CA1229726A - Thermoplastic dispensing device with manually operated feed magazine - Google Patents
Thermoplastic dispensing device with manually operated feed magazineInfo
- Publication number
- CA1229726A CA1229726A CA000471893A CA471893A CA1229726A CA 1229726 A CA1229726 A CA 1229726A CA 000471893 A CA000471893 A CA 000471893A CA 471893 A CA471893 A CA 471893A CA 1229726 A CA1229726 A CA 1229726A
- Authority
- CA
- Canada
- Prior art keywords
- block
- chamber
- sleeve
- magazine
- thermoplastic material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Abstract of the Disclosure A device for dispensing molten thermoplastic material which an operator grips while using his thumb to press a solid block of the thermoplastic material through a sleeve and into a heated melting chamber from which the molten thermoplastic material is discharged through a nozzle. The device includes a magazine assembly adapted to hold a stack of thermoplastic material blocks which can be moved seriatim into the sleeve by reciprocation of a slide.
Description
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This inven-tion relates to devices for dispensing molten thermoplastic mi~terials.
Many devices are known for dispensing molten thermo-plastic materials, such as -the prior art devices described in United States Patents Nos. 3,204,828 and 3,298,572.
Generally, such devices comprise a barrel member having an internal melting chamber which communicates with an outlet opening through a nozzle, and a sleeve with a through opening having one end secured to the barrel member with its through open-ing communica-ting with -the end of -the melting chamber opposite the nozzle. The sleeve is adapted to receive an elongate cylindrical block of solid thermoplastic material which fits closely within the through opening in the sleeve, with one end portion of the block in the melting chamber and the other end portion projecting through t:he sleeve. Means are provided for heating the barrel member to melt the end portion of the block therein, and the device includes a handle positioned so that an operator can grip the hand].e with the fingers of one hand while pressing ~he bloclc through t:he sleeve and into the melting chamber with -the thumb of that hand to force molten thermoplastic material ou-t oE the melt-ing chamber through the nozzle.
While such devices function effect:ively, a problem can occur after the operator places a second block of thermoplastic material end to end with the block in the sleeve and presses on the outer end of the second block. The operator must hold the second block in place, thus occupying the operator's second hand, which may be needed elsewhere such as to manipulate articles to which the molten thermoplastic material is being applied. If the ~L,2~t~
This inven-tion relates to devices for dispensing molten thermoplastic mi~terials.
Many devices are known for dispensing molten thermo-plastic materials, such as -the prior art devices described in United States Patents Nos. 3,204,828 and 3,298,572.
Generally, such devices comprise a barrel member having an internal melting chamber which communicates with an outlet opening through a nozzle, and a sleeve with a through opening having one end secured to the barrel member with its through open-ing communica-ting with -the end of -the melting chamber opposite the nozzle. The sleeve is adapted to receive an elongate cylindrical block of solid thermoplastic material which fits closely within the through opening in the sleeve, with one end portion of the block in the melting chamber and the other end portion projecting through t:he sleeve. Means are provided for heating the barrel member to melt the end portion of the block therein, and the device includes a handle positioned so that an operator can grip the hand].e with the fingers of one hand while pressing ~he bloclc through t:he sleeve and into the melting chamber with -the thumb of that hand to force molten thermoplastic material ou-t oE the melt-ing chamber through the nozzle.
While such devices function effect:ively, a problem can occur after the operator places a second block of thermoplastic material end to end with the block in the sleeve and presses on the outer end of the second block. The operator must hold the second block in place, thus occupying the operator's second hand, which may be needed elsewhere such as to manipulate articles to which the molten thermoplastic material is being applied. If the ~L,2~t~
-2- 557-2857 operator does no-t hold the second block, in place and releases the pressure on the second block as mus-t be done to stop -the -Elow of the molten thermoplastic material, or applies pressure in some direction other tha.n axially along -the second block before its leading end enters the sleeve, the second block can fall or fly away from the block already in the sleeve, which is inconvenien-t, distracting, and wasteful of the operator's time.
A device for dispensing molten thermoplastic material described in United Sta-tes Patent 4,552,287 provides, among other things, means for holding and properly positioning a second block of solid thermoplastic material at the end of a block of that material already in a sleeve and a melting barrel of a device of the type described above, even before the second block enters the outer end of the sleeve, thereby freeing the use oE the operator's second hand for o-ther activities.
That: device, however, will hold a maximum of less than three bl.ocks of thermoplastic material, and thus frequent loading of the device is requlred if the device is used continuously.
Summary of the Invention The present invention is a modification of the device described in United States Patent 4,552,287.
Also, preferably at least one inner sidewall of the magazine is formed with a plurality of recesses parallel to the axis of the melting chamber and adapted to partially receive the sides of the blocks, which recesses partia].ly receive the sides of blocks in the stack and restrict them from moving out the open top end of the magazine assembly when the device is tipped on its side.
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A device for dispensing molten thermoplastic material described in United Sta-tes Patent 4,552,287 provides, among other things, means for holding and properly positioning a second block of solid thermoplastic material at the end of a block of that material already in a sleeve and a melting barrel of a device of the type described above, even before the second block enters the outer end of the sleeve, thereby freeing the use oE the operator's second hand for o-ther activities.
That: device, however, will hold a maximum of less than three bl.ocks of thermoplastic material, and thus frequent loading of the device is requlred if the device is used continuously.
Summary of the Invention The present invention is a modification of the device described in United States Patent 4,552,287.
Also, preferably at least one inner sidewall of the magazine is formed with a plurality of recesses parallel to the axis of the melting chamber and adapted to partially receive the sides of the blocks, which recesses partia].ly receive the sides of blocks in the stack and restrict them from moving out the open top end of the magazine assembly when the device is tipped on its side.
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-3- 557-2857 srief Description of -the Drawing The present invention will be fu:rther described wi-th reference to the accompanying drawing wherein like numbers refer to like parts in the several views, and wherein:
Figure 1 is a side view of a first embodiment of a dispensing device described in United States Patent 4,552,287;
Figure 2 is a sectional side view of the dispensing device o:E Figure 2;
Figure 3 is an enlarged fragmentary sectional view of a barrel member, a sleeve, and a barrier ring therebetween in the dispensing device of Figure l;
Figure 4 is an enlarged sectional view taken approxi-mately along lines 4-4 of Figure 2; and Figure 5 is an end vlew of the dispensing device of Figure l;
Figure 6 is a side view oE a dispensing device according to the pr.esent invention which is similar to the device o:E Figure 1 except tha-t :Lt includes a manually operabl.e magazine assembly for holding blocks of solid thermoplastic material to be dispensed through the devicei Figure 7 is an end view of the dispensing device of Figure 6;
Figure 8 is an enlarged fragmentary sectional view of the magazine assembly in the device of Figure 6;
Figure 9 is an enlarged perspective view of a slide included in the magazine assembly in the device of Figure 6; and Figure 10 is a fragmentary sectional view taken approxi-mately along line 10-10 of Figure 8.
Figure 1 is a side view of a first embodiment of a dispensing device described in United States Patent 4,552,287;
Figure 2 is a sectional side view of the dispensing device o:E Figure 2;
Figure 3 is an enlarged fragmentary sectional view of a barrel member, a sleeve, and a barrier ring therebetween in the dispensing device of Figure l;
Figure 4 is an enlarged sectional view taken approxi-mately along lines 4-4 of Figure 2; and Figure 5 is an end vlew of the dispensing device of Figure l;
Figure 6 is a side view oE a dispensing device according to the pr.esent invention which is similar to the device o:E Figure 1 except tha-t :Lt includes a manually operabl.e magazine assembly for holding blocks of solid thermoplastic material to be dispensed through the devicei Figure 7 is an end view of the dispensing device of Figure 6;
Figure 8 is an enlarged fragmentary sectional view of the magazine assembly in the device of Figure 6;
Figure 9 is an enlarged perspective view of a slide included in the magazine assembly in the device of Figure 6; and Figure 10 is a fragmentary sectional view taken approxi-mately along line 10-10 of Figure 8.
-4- 557-2857 BrieE Description oE -the Drawing Referring now -to the drawing -the:re is shown in ~igures 1 through 5 a dispensing device Eor mol-ten thermoplastlc ma-terial generally des:ignated by the reference numeral 10, which was described in United States Patent 4,552,287.
Like known prior art dispensing devices for -thermo-plastic material, -the dispensing device lO comprises a two part Erame 12, a barrel member 14 mounted between the parts oE the Erame 12 and having an internal melting chamber 16 communicating via a discharge passageway 17 through a valve assembly 18 wi-th an outlet opening l9 through a nozzle 21, and a sleeve 20 with a cylindrical through opening 22 having one end secured to the barrel member 14 with its through opening 22 communicating with the end of the melting chamber 16 opposite the discharge passage-way 18. The sleeve 20 is adapted to receive a cylindrical block 24 of solid thermoplastic material within the cylindrical -through opening 22 with a slight clearance fi-t even when the diameter o:E
the block 24 is at the large end of i-ts tolerance range, with one end portion of the block 24 in the mel-ting chamber 16 and the block 24 37~
projecting through the opening 22 in the ~leeve 20. Means are provided in the device 10 for heating the barrel member 14 to melt the end portion of the block 24 therein. The frame 12 includes a handle 26 positioned 30 that an operator can grip the handle 26 with the fingers of one hand while applying pre~sure with the thumb of that hand to press the b:Lock 24 through the sleeve 20 and into the melting chamber 1~ and force molten thermoplastic material out of the melting chamber 16 through the valve assembly 18 and nozzle 21.
Unlike known prior art devices, the device 10 further includes a bracket as~embly 28 at the end of the sleeve 20 opposite the barrel member 14, which bracket assembly 28 includes means adapted for receiving and for lS holding a second block 24 of solid thermoplastic material in aligned end-to-end relationship with the block 24 of thermopla~tic material in the sleeve 20 while affording the application of force by the thumb of an operator on the end of the block 24 opposite the sleeve 20 to press the second block 24 through the sleeve 20 and into the melting chamber 16.
As illustrated, the bracket assembly 28 comprise~
spaced opposed gripping parts 30 of the frame 12 (Figure 5) that project toward the handle 26 in a position spaced from the outer end of the sleeve 20 and on opposite sides of an extension of the axis for the sleeve 20. The gripping parts 30 are biased toward each other by spring means comprising a channel-like member 29 of spring ~teel engaged around the top ~urfaces of the two parts of the frame 12 to help hold the two partC of the frame 12 t:ogether, and having opposed arcuate projecting portions 27 that are biased against the outer surfaces on the gripping parts 30 of the frame 12 The gripping partR 30 have distal ends spaced at a disltance that is les~ than the diameter oE the cylindrical block 24 of thermoplastic material, but which di~tance is sufficient so that thle block 24 can be trans-versely pressed therebetween to r~esiliently move the ~.Z~ 2~
gripping parts 30 away from each other in opposition to the biasing of the projecting portionq 27 and afford movement of the block 24 therebetween. Also, the gripping parts 30 have concave opposed inner surfaces adapted to conform to and engage the cylindrical side 3urfaces of a block 24 of thermoplasti.c material therebetween to hold the block 24 in alignment with a block 24 in the sleeve 20, while affording axial sliding movement of the block 24 and movement of the thumb of the operator between the gripping parts 30 to move the second block 24 into the sleeve 20.
The device also comprises a pressure plate 32 adapted to abut the end of the outermo~t block 24 of thermoplastic material opposite the melting chamber 16 and to be positioned between the block 2~ and the user' B thumb to transfer force therebetween. The plate 32 includes an elongate slide portion 33 (Figure 2) at one edge slideably mounted in a track 34 defined between the parts of the frame 12 to afford movement of the plate 32 with the block 24 and is shaped to paiss between the gripping parts 30 so that the plate 32 can be used to push the block 24 fully into tile sleeve 20 while directing forces applied to the plate 32 in the longitudinal direction of the block 24, and protecl:s an operator'~ thumb from contact with the thermo-plastic block 24 and from contact with any molten thermo-pla9tic material that (under unusual condLtions) mightextrude to the outer end of the sleeve 20. The pressure plate 32 includes two wing portionis 35, one projecting from each side, which wing portions 35 are positioned to pass under the gripping parts 30 as the pressure plate 32 is used to press the block 24 into the sleeve 20, and either of which wing portions 35 can be manually engaged to move the pressure plate 32 away from the sleeve 20 to facilitate placing a new block 24 of thermoplastic material between the gripping parts 30 after a previous block 24 has been pushed into the i~leeve 20.
The two parts of the frame 12 are molded of a suitable high-temperature resistant polymeric material '3'~2t~
~(e.g., the material commercially designated Dupon, Zytel FR50-NC10 available from E. I. duPont deNemours, Wilmington, Delaware). Both parts of the frame 12 are formed with spaced posts 36 projecting generally radially outwardly of the barrel member 14, which posts 36 can provide means for spacing the major side surface of the frame 12 and the nozzle 21 of the device 10 from a horizontal surface on which the device 10 is laid, and wh~ch posts 36 have sockets 37 adapted to receive end portions of a generally U-shaped wire 31 (Figure 5) to further space the device 10 away from such a surface should that be desired.
The sleeve 20 is made of a ~tiff heat-resistive polymeric material (e.g., Teflon~) made by an extrusion process to provide a polished inner surface with micro-scopic longitudinally extending scratches that facilitates movement of the thermop]astic material through the sleeve 20, particularly after molten thermoplastic has cooled in the sleeve 20 and is again heated by the device 10.
The sleeve 20 is coupled to the barrel member 14 by a metal barrier ring 38 (Figures 2 and 3) that is heated by the means for heating the barrel member 14, which barrier ring 38 provides means for restricting the extru-sion of mo:Lten thermoplastic material between the block 24 and t:he inner surface of the sleeve 20. The inlet barrier ring 38 is a generally cylindrical member having axially spaced radically outwardly projecting ribs 39 at one end positioned in a cylindrical socket in tlle end of the barrel member 14, between which ribs 39 is a sealing strip 40 pressed between the barrier ring 38 and barrel member 14 to provide a seal therebetween. An end portion 41 of the barrier ring 38 opposite the barrel member 14 is press fit into an internally relieved area of the sleeve 20. The barrier ring 38 has a cylindrical inside surface that is smaller in diameter than the inside dia0eter of the sleeve 20 (which sleeve 20 is adapted to always receive a block 24 with a slight clearance fit even when the diameter of the block 24 is at the upper end of its tolerance limits) ~o ~Y 7 ~ e~
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that the barrier ring 38 will receive a block 24 having a diameter at the upper end of its tolerance limitq with a slight interference fit (e.g., an interference of up to 0.025 cm) or will receive a block 24 having a diameter at the lower end oE it~ tolerance range with a clearance fit of about 0.050 cm. Surprisingly those blocks 24 with a diameter that prc,vides such a slight interference fit with the barrier ring 38 will be melted sufficiently around their periphery by the heated barrier ring 38 that they can be easily pressed into the melting chamber 16, and blocks 24 of thermoplastic material with diameters that provide either such slight interference fits or clearance fits fit ~uf~iciently close Ln the barrier ring 38 so that no signi-ficant amount of molten polymeric material will extrude out of the melting chamber 16 between the block 24 and the barrier ring 38 and toward the outer ënd of the sleeve 20 between the block 24 and the sleeve 20.
The device 10 also includes three metal (pre~er-ably brass) cooling flanges around the outer periphery of the s]eeve 20 that provide means for developing predeter-mined temperature zones in the sleeve 20, includinq two closely spaced regulating flanges 45 at the end of the sleev6! 20 adjacent the barrier ring 38 which cool and regulate the temperature of the molten thermoplastic materLal in the area between the barrier ring 3~ and the sleeve 20, and a cooling flange 48 about centered along the length of the sleeve 20 that cools the sleeve to restrict the thermoplastic material from becoming molten past that area along the sleeve 20, even if the heating means is activated for a long period of time during which molten thermoplastic material is not being dispensed from the device 10.
The barrel member 14 is of a ~uitable metal (e.g., aluminum). The melting chamber 16 in the barrel 14 is defined by a generally frustoconical inner surface tapered toward the valve assembly 18 to direct the molten polymeric material to the dicharcle passageway 17 through 7Z~
g the valve assembly 18, and four eq~ally ~paced radially inwardly projecting ribs 42 which provide heated contact surfaces in addition to the frustoconical inner s~rface for engaging and ~elting the block~ 24 of thermoplastic material as they are pressed into the chamber 16. An electric heating element 43 which heats both the barrel member 14 and the barrier ring 38 is positioned in a socket 44 in the barrel member 14 beneath the chamber 16, and a thermostat 46 is fixed in a channel below the heating element 43 to di~connect electrical power normally supplied the heating element 43 via a power cord 47 and the thermo-stat 46 when the temperature of the ba~rel member 14 at the thermostat 46 exceeds a predetermined maximum (e.g., 200C).
The valve assembly 18 between the barrel member 14 and the nozzle 21 provides valve means for restricting molten thermoplastic material from running out of the nozzle 21 until a predetermined amount of force te.g., about 0.9 to 1.8 kilograms) is manually applied to the block 24 of thermostatic material 24 to cause pressure in the molten thermoplastic material in the melting chamber 16. The valve assembly 18 is of the poppet valve type and includes a valve body 49 secured between the barrel member 14 and nozzle 21, which valve body 49 defines the dic~charge passageway 17 communicating between the melting chamber 16 and the opening 19 through the noæzle 21. The discharge passageway 17 through the valve body 49 is normally closed by a head 50 on a valve normally biased against a valve seat on the end of the valve body 49 adjacent the nozzle 21 by a spring 52 compressed between a flanc~e on the valve body 49 and a perforated retaining disk 54 fixed on a stem 53 of the valve~ which disk 54 is axially slidably mounted in the valve body 49. Pressure from molten thermoplastic material in the melting chamber 16 and discharge passageway 17 caused by pressure manually applied to the block 24 of thermoplastic material can move the valve head 50 away from its seat against: the bias of the spring 52 and allow molten 2~j thermopla~tic material to pass the valve head 50 and be discharged through the nozzle 21. When the opera~or releases such pressure, however, the valve head 50 will again move to its seat under the influ0nce of the spring 52 to prevent any more molten thermoplastic material within the melting chamber 16 and discharge passageway 17 from escaping through the nozzle 21.
'rO use the dispensing device 10, an operator first connects the power cord 47 to a source of electrical power so that the barrel member 14 and barrier ring 28 are heated by the heating element 43. The operator then places the block 24 of thermoplastic material in the opening 22 through the ~leeve 20, grabs the handle 26 with one hand, and u~es the thumb of that hand to pres3 against the pressure plate 32 to slide it along the track 34 into engagement w:ith the block 24 and thereby press the block 24 through the sleeve 20 and barrier ring 38 and into the melting chamber 16 in the barrel member 14 where the end portion of the block 24 will be made molten by contact with the inner surface of the barrel member 14, including the inwardly projecting ribs 42. While the inner surface of the sleeve 20 will provide a clearance fit with the periphery of the block 24, even if the diameter of the block 24 is at the upper limit of its tolerance range, the barrier ring 3~ has a cylindrical inner surface with a ~lightly smaller inner diameter than the inner diameter of the sleeve 20 and will provide a slight interference fit or a very close clearance fit with the block 24, depending on whether the diameter of the block 24 is at the upper or lower limit of its tolerance range. If there is an inter-ference fit, the barrier ring 38 will melt the periphery ofthe thermoplastic block 24 sufficiently to allow it to easily pass; and in either event the barrier ring 38 will greatly restric:t extrusion of thermopla~itic material from the melting chcamber 16 back between the block 24 and the barrier ring 3~ and thus between the block 24 and the inner surface of the sleeve 20. Sufficient pressure in the 37~
molten thermoplastic within the melting chamber 16 caused by manual pressure on the pres~ure plate 32 and block 2~
will cause the head 50 of the value to move away from its valve seat against the bias o the spring 52 so that the molten thermoplastic can flow around the head 50 and out the outlet opening 19 of the nozzle 21. When manual pres3ure is released on the pres3ure plate 32, the head 50 will again move to its seat under the influence of the ~3pring 52 which stops the flow of molten material through the nozzle 21 and restricts air from reaching the molten thermoplastic material in the melting chamber 16, thereby restricting oxidation of the molten thermoplastic in the valve a~3sembly 18. IE the heating element 43 remains activated for a long time while no molten thermoplastic material is dispensed through the nozzle 21, heat buildup can cause the block 24 to melt (at least around its periphery), to about the midpoint of the sleeve 20 where such melting will be restricted by the cooling effect of the cooling flange 4~. If the power is then disconnected so that this molten thermoplastic material cools and solidifies, and the power is then again connected to heat the heating element 43, the thermoplastic material in the valve assembly 18 will be some of the first thermoplastic material melted and the valve a~sembly 18 can act as a relief valve for pressure developed in the barrel member 14 as the rest of the thermoplastic material in the barrel member 14 melts. Also~ the smooth longit:udinally micro-grooved inner surface of the sleeve 20 wi.ll facilitate breaking loose of the block 24 from the sleeve 20 to press it through the barrier ring 38 and into l:he melting chamber 16 to again cause the molten thermoplastiic material to flow out of the nozzle 21.
When the outer end of the bloc]c 24 of thermo-plastic materia:l reaches the outer end of the sleeve 20, the operator can manually retract the pressure plate 32 along it~3 track 34 via one of the wing portions 35 and press a new block 24 of thermoplastic material transversely 7~
between the gripping part~ 30 of the holding bracket 2~, whereupon the new block 24 will be held in proper alignment with the sleeve 20, and the operator can again u~e the pre~sure plate 32 to pre~s the new block 24 into the melting chamber 16.
Referring now to Figures 6 through 10 of the drawing there is ~hown a dispensing device 60 for molten thermopla~tic material according to the present invention which device 60 has the same structure as the device 10 except that the bracket assembly 28 and slide portion 33 of the device 10 have been replaced by a manually operated magazine assembly 62. Parts of the device 60 that have the ~ame ~tructures as parts of the device 10 have been given the same reference numerals to which have been added the suffix "an.
Like the dispen~ing device 10 the device 60 comprises a two part frame 64, a barrel member 14a mounted between the parts of the frame 64 and having an internal melting chamber communicating via a di~charge passageway through a valve assembly 18a with an outlet opening through a nozzle 21a, and a sleeve 20a with a cylindrical through opening 22a having one end secured to the barrel member 14a with its through opening 22a communicating with the end of the melting chamber opposite the discharge passageway. The slQeve 20a i~ adapted to receive a cylindrical block 24 of solid thermoplastic material within the cylindrical through opening 22a with a slight clearance fit even when the diameter of the block 24 is at the large end of its tolerance range, with one end portion of the block 24 in the melting chamber and the block 24 projecting through the opening 22a in the sleeve 20a. Means are provided in the device 60 for heating the barrel member t:o melt the end portion of the block 24 therein. The frame 64 includes a handle 26a posil:ioned 90 that an operator can grip the handle 26a with the fingers of one hand while applying pressure with the thumb of that hand to press the block 24 through the sleeve 20a and into the melting chamber to force molten thermoplastic material out of the melting chamber through the valve assembly 18a and nozzle 21a.
Unlike the device 10, the device 60 includes the magazine assembly 62 at the end of the sleeve 20a opposite the barrel member 14a, which magazine a~sembly 62 includes mean~ adapted for receiving and for holding a stack of the blocks 24 of solid thermoplastic material with the lowermost block 24 of the stack in aligned end-to-end relationship with a block 24 of thermoplastic material in the s~eeve 20a~ while affording the application of force by the thumb of an operator on the end of the lowermost block 24 opposite the sleeve 20a to pres~ it into the sleeve 20a toward the melting chamber.
As illustrated, the magazine a~sembly 62 comprises (1) wall means or walls included in the frame 64 that define an open topped magazine chamber 66 adapted to hold a stack of the solid thermoplastic material blocks 24 with the lowermost block 24 of the stack in aligned end-to-end relationship with a block 24 of thermoplastic materLal in the sleeve 20a; and (2) an elongate slide 68 having an end ~urface 69 adapted to engage the end of the lowermost block 24 opposite the sleeve 20a, a shape adapted to replace the lowermo~t block 24 in the stack, and an upper surface 70 adapted to support the other blocks 2~ in the stack. Also, the slide 68 has portions projecting away from its side opposite its surface 70 that are longitudinally spaced to provide! a notch 72 therebetween opening through its side. The notch 72 is adapted to receive the end portion of an operator's thumb. The slide 68 is mounted on the frame 64 for movement along a path generally aligned with the melting chamber (1) from a retracted position (Figures 6 and 8) with the slide 68 out of the magazine chamber 66 and its first end surface 69 adjacent the end of the lowermost block in the magazine chamber 66 opposite the melting chamber (2) to an advanced position (dotted outline in Figure 6) with the slide 68 extending across the bottom of the magazine chamber 66 to ~ 2;~ 2~i pres~ the lowermo~t block 24 in the magazine chamber 66 toward the melting chamber by engagement between its first end surface 69 and the block 24, in which advanced position the slide 68 supports the other blocks 24 in the magazine chamber 66 on its upper surface 70 and (3) back to its retracted position to allow the block 24 in the stack adjacent its uppe!r surface 70 to move into alignment with the melting chamber so that the cycle can be repeated. The notch 72 is accessible by the thumb of an operator gripping the handle 26a to afford manual reciprocation of the slide 68 between its retracted and advanced positions by the operator.
The walls of the frame 64 which define the magazine chamber 66 include spaced opposed ledges 74 which define a bottom wall for the magazine chamber 66, and the slide 68 has opposite longitudinally grooves extending receive the ledges 74 to afford reciprocation of the slide 68 along the ledges 74 between its retracted and advanced positions.
Also the walls of the frame 64 defining the magazLne chamber 66 include spaced vertically extending side walls 76. At least one of the side walls 76 has a plurality of recesses 78 parallel to each other and to the axis of the melting chamber along its inner surface. The reces~es 78 are spaced and adapted to partially receive the sides of blocks 24 in the stack of blocks 24 in the magazine chamber 66 to restrict the blocks 24 from moving out the open top of the magazine chamber 66 when the device 60 i9 tipped on its ~ide adjacent the recesses 78. Two resilient spring fingers 77 with enlarged inwardly projecting head~ on their distal ends and po~itioned adjacent the open end of the magazine chamber 66 also help to retain the stack of block~ 24 in the magazine chamber 66, while beincl re~iliently bendable so that their heads will be cammed out of the magazine chamber as blocks 24 are added to the sl:ack in the magazine assembly 62.
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To use the dispensing device 60, an operator fir~t connects its power cord 47 to a source of electrical power so that the barrel member and barrier ring are heated by its heating element. After insuring the slide 68 is then it it~ retracted position (Figures 6 and a), the operator then places a series of blocks 24 of thermoplastic material in the open end o the magazine chamber 66, grabs the handle 26a with one hand, engages the thumb of that hand in the notch 72 in the slide 68 and uses his thumb to move the slide 68 along the ledges 74 into engagement with the lowermost block 24 in the stack to thereby press that block 24 toward the sleeve 20a and into the melting chamber in the barrel member 14a where the end portion of the block 24 will be made molten by contact with the inner surface of the barrel member 14a. As the slide 68 is thu~ moved from its retracted position toward it~ advanced position (dotted outline in Figure 6) it will replace the lowermost block 24 in the magazine chamber and support the other blocks in the magazine chamber 66 on its upper surface 70.
When the outer end of the thermopla~tic material and the end surface 69 of the slide 68 reach the outer end of the sleeve lOa~ (the advance position of the slide 68) the operator can manually retract the slide 68 along the ledges 74 by engagement of hi~ thumb in the notch 72 or on one of a pair of projecting wing portions 79, 80 that the lowermost block 24 of thermoplastic material remaining in the magazine chamber will move to the bottom o the magazine chamber 66 in proper alignment with the sleeve 20a, and the operator can again manipulate the slide 68 with his thumb to press the new lowermost block 24 in the magazine chamber 66 into the sleeve 20a and the melting chamber.
The present invention has now been described with reference to one embodiment thereof. It will be apparent to those skilled in the art that many change~ can be made in the embodiment described witllout departing from the scope of the present invention. For example, the device 60 2~i could incorporate the features described with reference to drawing Figures 6 and 7 of United States Paten-t 4,552,287. Also recesses 78 of the type illustrated could be used on the other sidewall defining the magazine chamber 66 instead of the spring fingers 77.
Thus the scope of the present invention should not be limited to the structures described in this application, but only by struc-tures described by the language of the claim and their equivalents.
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Like known prior art dispensing devices for -thermo-plastic material, -the dispensing device lO comprises a two part Erame 12, a barrel member 14 mounted between the parts oE the Erame 12 and having an internal melting chamber 16 communicating via a discharge passageway 17 through a valve assembly 18 wi-th an outlet opening l9 through a nozzle 21, and a sleeve 20 with a cylindrical through opening 22 having one end secured to the barrel member 14 with its through opening 22 communicating with the end of the melting chamber 16 opposite the discharge passage-way 18. The sleeve 20 is adapted to receive a cylindrical block 24 of solid thermoplastic material within the cylindrical -through opening 22 with a slight clearance fi-t even when the diameter o:E
the block 24 is at the large end of i-ts tolerance range, with one end portion of the block 24 in the mel-ting chamber 16 and the block 24 37~
projecting through the opening 22 in the ~leeve 20. Means are provided in the device 10 for heating the barrel member 14 to melt the end portion of the block 24 therein. The frame 12 includes a handle 26 positioned 30 that an operator can grip the handle 26 with the fingers of one hand while applying pre~sure with the thumb of that hand to press the b:Lock 24 through the sleeve 20 and into the melting chamber 1~ and force molten thermoplastic material out of the melting chamber 16 through the valve assembly 18 and nozzle 21.
Unlike known prior art devices, the device 10 further includes a bracket as~embly 28 at the end of the sleeve 20 opposite the barrel member 14, which bracket assembly 28 includes means adapted for receiving and for lS holding a second block 24 of solid thermoplastic material in aligned end-to-end relationship with the block 24 of thermopla~tic material in the sleeve 20 while affording the application of force by the thumb of an operator on the end of the block 24 opposite the sleeve 20 to press the second block 24 through the sleeve 20 and into the melting chamber 16.
As illustrated, the bracket assembly 28 comprise~
spaced opposed gripping parts 30 of the frame 12 (Figure 5) that project toward the handle 26 in a position spaced from the outer end of the sleeve 20 and on opposite sides of an extension of the axis for the sleeve 20. The gripping parts 30 are biased toward each other by spring means comprising a channel-like member 29 of spring ~teel engaged around the top ~urfaces of the two parts of the frame 12 to help hold the two partC of the frame 12 t:ogether, and having opposed arcuate projecting portions 27 that are biased against the outer surfaces on the gripping parts 30 of the frame 12 The gripping partR 30 have distal ends spaced at a disltance that is les~ than the diameter oE the cylindrical block 24 of thermoplastic material, but which di~tance is sufficient so that thle block 24 can be trans-versely pressed therebetween to r~esiliently move the ~.Z~ 2~
gripping parts 30 away from each other in opposition to the biasing of the projecting portionq 27 and afford movement of the block 24 therebetween. Also, the gripping parts 30 have concave opposed inner surfaces adapted to conform to and engage the cylindrical side 3urfaces of a block 24 of thermoplasti.c material therebetween to hold the block 24 in alignment with a block 24 in the sleeve 20, while affording axial sliding movement of the block 24 and movement of the thumb of the operator between the gripping parts 30 to move the second block 24 into the sleeve 20.
The device also comprises a pressure plate 32 adapted to abut the end of the outermo~t block 24 of thermoplastic material opposite the melting chamber 16 and to be positioned between the block 2~ and the user' B thumb to transfer force therebetween. The plate 32 includes an elongate slide portion 33 (Figure 2) at one edge slideably mounted in a track 34 defined between the parts of the frame 12 to afford movement of the plate 32 with the block 24 and is shaped to paiss between the gripping parts 30 so that the plate 32 can be used to push the block 24 fully into tile sleeve 20 while directing forces applied to the plate 32 in the longitudinal direction of the block 24, and protecl:s an operator'~ thumb from contact with the thermo-plastic block 24 and from contact with any molten thermo-pla9tic material that (under unusual condLtions) mightextrude to the outer end of the sleeve 20. The pressure plate 32 includes two wing portionis 35, one projecting from each side, which wing portions 35 are positioned to pass under the gripping parts 30 as the pressure plate 32 is used to press the block 24 into the sleeve 20, and either of which wing portions 35 can be manually engaged to move the pressure plate 32 away from the sleeve 20 to facilitate placing a new block 24 of thermoplastic material between the gripping parts 30 after a previous block 24 has been pushed into the i~leeve 20.
The two parts of the frame 12 are molded of a suitable high-temperature resistant polymeric material '3'~2t~
~(e.g., the material commercially designated Dupon, Zytel FR50-NC10 available from E. I. duPont deNemours, Wilmington, Delaware). Both parts of the frame 12 are formed with spaced posts 36 projecting generally radially outwardly of the barrel member 14, which posts 36 can provide means for spacing the major side surface of the frame 12 and the nozzle 21 of the device 10 from a horizontal surface on which the device 10 is laid, and wh~ch posts 36 have sockets 37 adapted to receive end portions of a generally U-shaped wire 31 (Figure 5) to further space the device 10 away from such a surface should that be desired.
The sleeve 20 is made of a ~tiff heat-resistive polymeric material (e.g., Teflon~) made by an extrusion process to provide a polished inner surface with micro-scopic longitudinally extending scratches that facilitates movement of the thermop]astic material through the sleeve 20, particularly after molten thermoplastic has cooled in the sleeve 20 and is again heated by the device 10.
The sleeve 20 is coupled to the barrel member 14 by a metal barrier ring 38 (Figures 2 and 3) that is heated by the means for heating the barrel member 14, which barrier ring 38 provides means for restricting the extru-sion of mo:Lten thermoplastic material between the block 24 and t:he inner surface of the sleeve 20. The inlet barrier ring 38 is a generally cylindrical member having axially spaced radically outwardly projecting ribs 39 at one end positioned in a cylindrical socket in tlle end of the barrel member 14, between which ribs 39 is a sealing strip 40 pressed between the barrier ring 38 and barrel member 14 to provide a seal therebetween. An end portion 41 of the barrier ring 38 opposite the barrel member 14 is press fit into an internally relieved area of the sleeve 20. The barrier ring 38 has a cylindrical inside surface that is smaller in diameter than the inside dia0eter of the sleeve 20 (which sleeve 20 is adapted to always receive a block 24 with a slight clearance fit even when the diameter of the block 24 is at the upper end of its tolerance limits) ~o ~Y 7 ~ e~
~1 2~97~
that the barrier ring 38 will receive a block 24 having a diameter at the upper end of its tolerance limitq with a slight interference fit (e.g., an interference of up to 0.025 cm) or will receive a block 24 having a diameter at the lower end oE it~ tolerance range with a clearance fit of about 0.050 cm. Surprisingly those blocks 24 with a diameter that prc,vides such a slight interference fit with the barrier ring 38 will be melted sufficiently around their periphery by the heated barrier ring 38 that they can be easily pressed into the melting chamber 16, and blocks 24 of thermoplastic material with diameters that provide either such slight interference fits or clearance fits fit ~uf~iciently close Ln the barrier ring 38 so that no signi-ficant amount of molten polymeric material will extrude out of the melting chamber 16 between the block 24 and the barrier ring 38 and toward the outer ënd of the sleeve 20 between the block 24 and the sleeve 20.
The device 10 also includes three metal (pre~er-ably brass) cooling flanges around the outer periphery of the s]eeve 20 that provide means for developing predeter-mined temperature zones in the sleeve 20, includinq two closely spaced regulating flanges 45 at the end of the sleev6! 20 adjacent the barrier ring 38 which cool and regulate the temperature of the molten thermoplastic materLal in the area between the barrier ring 3~ and the sleeve 20, and a cooling flange 48 about centered along the length of the sleeve 20 that cools the sleeve to restrict the thermoplastic material from becoming molten past that area along the sleeve 20, even if the heating means is activated for a long period of time during which molten thermoplastic material is not being dispensed from the device 10.
The barrel member 14 is of a ~uitable metal (e.g., aluminum). The melting chamber 16 in the barrel 14 is defined by a generally frustoconical inner surface tapered toward the valve assembly 18 to direct the molten polymeric material to the dicharcle passageway 17 through 7Z~
g the valve assembly 18, and four eq~ally ~paced radially inwardly projecting ribs 42 which provide heated contact surfaces in addition to the frustoconical inner s~rface for engaging and ~elting the block~ 24 of thermoplastic material as they are pressed into the chamber 16. An electric heating element 43 which heats both the barrel member 14 and the barrier ring 38 is positioned in a socket 44 in the barrel member 14 beneath the chamber 16, and a thermostat 46 is fixed in a channel below the heating element 43 to di~connect electrical power normally supplied the heating element 43 via a power cord 47 and the thermo-stat 46 when the temperature of the ba~rel member 14 at the thermostat 46 exceeds a predetermined maximum (e.g., 200C).
The valve assembly 18 between the barrel member 14 and the nozzle 21 provides valve means for restricting molten thermoplastic material from running out of the nozzle 21 until a predetermined amount of force te.g., about 0.9 to 1.8 kilograms) is manually applied to the block 24 of thermostatic material 24 to cause pressure in the molten thermoplastic material in the melting chamber 16. The valve assembly 18 is of the poppet valve type and includes a valve body 49 secured between the barrel member 14 and nozzle 21, which valve body 49 defines the dic~charge passageway 17 communicating between the melting chamber 16 and the opening 19 through the noæzle 21. The discharge passageway 17 through the valve body 49 is normally closed by a head 50 on a valve normally biased against a valve seat on the end of the valve body 49 adjacent the nozzle 21 by a spring 52 compressed between a flanc~e on the valve body 49 and a perforated retaining disk 54 fixed on a stem 53 of the valve~ which disk 54 is axially slidably mounted in the valve body 49. Pressure from molten thermoplastic material in the melting chamber 16 and discharge passageway 17 caused by pressure manually applied to the block 24 of thermoplastic material can move the valve head 50 away from its seat against: the bias of the spring 52 and allow molten 2~j thermopla~tic material to pass the valve head 50 and be discharged through the nozzle 21. When the opera~or releases such pressure, however, the valve head 50 will again move to its seat under the influ0nce of the spring 52 to prevent any more molten thermoplastic material within the melting chamber 16 and discharge passageway 17 from escaping through the nozzle 21.
'rO use the dispensing device 10, an operator first connects the power cord 47 to a source of electrical power so that the barrel member 14 and barrier ring 28 are heated by the heating element 43. The operator then places the block 24 of thermoplastic material in the opening 22 through the ~leeve 20, grabs the handle 26 with one hand, and u~es the thumb of that hand to pres3 against the pressure plate 32 to slide it along the track 34 into engagement w:ith the block 24 and thereby press the block 24 through the sleeve 20 and barrier ring 38 and into the melting chamber 16 in the barrel member 14 where the end portion of the block 24 will be made molten by contact with the inner surface of the barrel member 14, including the inwardly projecting ribs 42. While the inner surface of the sleeve 20 will provide a clearance fit with the periphery of the block 24, even if the diameter of the block 24 is at the upper limit of its tolerance range, the barrier ring 3~ has a cylindrical inner surface with a ~lightly smaller inner diameter than the inner diameter of the sleeve 20 and will provide a slight interference fit or a very close clearance fit with the block 24, depending on whether the diameter of the block 24 is at the upper or lower limit of its tolerance range. If there is an inter-ference fit, the barrier ring 38 will melt the periphery ofthe thermoplastic block 24 sufficiently to allow it to easily pass; and in either event the barrier ring 38 will greatly restric:t extrusion of thermopla~itic material from the melting chcamber 16 back between the block 24 and the barrier ring 3~ and thus between the block 24 and the inner surface of the sleeve 20. Sufficient pressure in the 37~
molten thermoplastic within the melting chamber 16 caused by manual pressure on the pres~ure plate 32 and block 2~
will cause the head 50 of the value to move away from its valve seat against the bias o the spring 52 so that the molten thermoplastic can flow around the head 50 and out the outlet opening 19 of the nozzle 21. When manual pres3ure is released on the pres3ure plate 32, the head 50 will again move to its seat under the influence of the ~3pring 52 which stops the flow of molten material through the nozzle 21 and restricts air from reaching the molten thermoplastic material in the melting chamber 16, thereby restricting oxidation of the molten thermoplastic in the valve a~3sembly 18. IE the heating element 43 remains activated for a long time while no molten thermoplastic material is dispensed through the nozzle 21, heat buildup can cause the block 24 to melt (at least around its periphery), to about the midpoint of the sleeve 20 where such melting will be restricted by the cooling effect of the cooling flange 4~. If the power is then disconnected so that this molten thermoplastic material cools and solidifies, and the power is then again connected to heat the heating element 43, the thermoplastic material in the valve assembly 18 will be some of the first thermoplastic material melted and the valve a~sembly 18 can act as a relief valve for pressure developed in the barrel member 14 as the rest of the thermoplastic material in the barrel member 14 melts. Also~ the smooth longit:udinally micro-grooved inner surface of the sleeve 20 wi.ll facilitate breaking loose of the block 24 from the sleeve 20 to press it through the barrier ring 38 and into l:he melting chamber 16 to again cause the molten thermoplastiic material to flow out of the nozzle 21.
When the outer end of the bloc]c 24 of thermo-plastic materia:l reaches the outer end of the sleeve 20, the operator can manually retract the pressure plate 32 along it~3 track 34 via one of the wing portions 35 and press a new block 24 of thermoplastic material transversely 7~
between the gripping part~ 30 of the holding bracket 2~, whereupon the new block 24 will be held in proper alignment with the sleeve 20, and the operator can again u~e the pre~sure plate 32 to pre~s the new block 24 into the melting chamber 16.
Referring now to Figures 6 through 10 of the drawing there is ~hown a dispensing device 60 for molten thermopla~tic material according to the present invention which device 60 has the same structure as the device 10 except that the bracket assembly 28 and slide portion 33 of the device 10 have been replaced by a manually operated magazine assembly 62. Parts of the device 60 that have the ~ame ~tructures as parts of the device 10 have been given the same reference numerals to which have been added the suffix "an.
Like the dispen~ing device 10 the device 60 comprises a two part frame 64, a barrel member 14a mounted between the parts of the frame 64 and having an internal melting chamber communicating via a di~charge passageway through a valve assembly 18a with an outlet opening through a nozzle 21a, and a sleeve 20a with a cylindrical through opening 22a having one end secured to the barrel member 14a with its through opening 22a communicating with the end of the melting chamber opposite the discharge passageway. The slQeve 20a i~ adapted to receive a cylindrical block 24 of solid thermoplastic material within the cylindrical through opening 22a with a slight clearance fit even when the diameter of the block 24 is at the large end of its tolerance range, with one end portion of the block 24 in the melting chamber and the block 24 projecting through the opening 22a in the sleeve 20a. Means are provided in the device 60 for heating the barrel member t:o melt the end portion of the block 24 therein. The frame 64 includes a handle 26a posil:ioned 90 that an operator can grip the handle 26a with the fingers of one hand while applying pressure with the thumb of that hand to press the block 24 through the sleeve 20a and into the melting chamber to force molten thermoplastic material out of the melting chamber through the valve assembly 18a and nozzle 21a.
Unlike the device 10, the device 60 includes the magazine assembly 62 at the end of the sleeve 20a opposite the barrel member 14a, which magazine a~sembly 62 includes mean~ adapted for receiving and for holding a stack of the blocks 24 of solid thermoplastic material with the lowermost block 24 of the stack in aligned end-to-end relationship with a block 24 of thermoplastic material in the s~eeve 20a~ while affording the application of force by the thumb of an operator on the end of the lowermost block 24 opposite the sleeve 20a to pres~ it into the sleeve 20a toward the melting chamber.
As illustrated, the magazine a~sembly 62 comprises (1) wall means or walls included in the frame 64 that define an open topped magazine chamber 66 adapted to hold a stack of the solid thermoplastic material blocks 24 with the lowermost block 24 of the stack in aligned end-to-end relationship with a block 24 of thermoplastic materLal in the sleeve 20a; and (2) an elongate slide 68 having an end ~urface 69 adapted to engage the end of the lowermost block 24 opposite the sleeve 20a, a shape adapted to replace the lowermo~t block 24 in the stack, and an upper surface 70 adapted to support the other blocks 2~ in the stack. Also, the slide 68 has portions projecting away from its side opposite its surface 70 that are longitudinally spaced to provide! a notch 72 therebetween opening through its side. The notch 72 is adapted to receive the end portion of an operator's thumb. The slide 68 is mounted on the frame 64 for movement along a path generally aligned with the melting chamber (1) from a retracted position (Figures 6 and 8) with the slide 68 out of the magazine chamber 66 and its first end surface 69 adjacent the end of the lowermost block in the magazine chamber 66 opposite the melting chamber (2) to an advanced position (dotted outline in Figure 6) with the slide 68 extending across the bottom of the magazine chamber 66 to ~ 2;~ 2~i pres~ the lowermo~t block 24 in the magazine chamber 66 toward the melting chamber by engagement between its first end surface 69 and the block 24, in which advanced position the slide 68 supports the other blocks 24 in the magazine chamber 66 on its upper surface 70 and (3) back to its retracted position to allow the block 24 in the stack adjacent its uppe!r surface 70 to move into alignment with the melting chamber so that the cycle can be repeated. The notch 72 is accessible by the thumb of an operator gripping the handle 26a to afford manual reciprocation of the slide 68 between its retracted and advanced positions by the operator.
The walls of the frame 64 which define the magazine chamber 66 include spaced opposed ledges 74 which define a bottom wall for the magazine chamber 66, and the slide 68 has opposite longitudinally grooves extending receive the ledges 74 to afford reciprocation of the slide 68 along the ledges 74 between its retracted and advanced positions.
Also the walls of the frame 64 defining the magazLne chamber 66 include spaced vertically extending side walls 76. At least one of the side walls 76 has a plurality of recesses 78 parallel to each other and to the axis of the melting chamber along its inner surface. The reces~es 78 are spaced and adapted to partially receive the sides of blocks 24 in the stack of blocks 24 in the magazine chamber 66 to restrict the blocks 24 from moving out the open top of the magazine chamber 66 when the device 60 i9 tipped on its ~ide adjacent the recesses 78. Two resilient spring fingers 77 with enlarged inwardly projecting head~ on their distal ends and po~itioned adjacent the open end of the magazine chamber 66 also help to retain the stack of block~ 24 in the magazine chamber 66, while beincl re~iliently bendable so that their heads will be cammed out of the magazine chamber as blocks 24 are added to the sl:ack in the magazine assembly 62.
2~
To use the dispensing device 60, an operator fir~t connects its power cord 47 to a source of electrical power so that the barrel member and barrier ring are heated by its heating element. After insuring the slide 68 is then it it~ retracted position (Figures 6 and a), the operator then places a series of blocks 24 of thermoplastic material in the open end o the magazine chamber 66, grabs the handle 26a with one hand, engages the thumb of that hand in the notch 72 in the slide 68 and uses his thumb to move the slide 68 along the ledges 74 into engagement with the lowermost block 24 in the stack to thereby press that block 24 toward the sleeve 20a and into the melting chamber in the barrel member 14a where the end portion of the block 24 will be made molten by contact with the inner surface of the barrel member 14a. As the slide 68 is thu~ moved from its retracted position toward it~ advanced position (dotted outline in Figure 6) it will replace the lowermost block 24 in the magazine chamber and support the other blocks in the magazine chamber 66 on its upper surface 70.
When the outer end of the thermopla~tic material and the end surface 69 of the slide 68 reach the outer end of the sleeve lOa~ (the advance position of the slide 68) the operator can manually retract the slide 68 along the ledges 74 by engagement of hi~ thumb in the notch 72 or on one of a pair of projecting wing portions 79, 80 that the lowermost block 24 of thermoplastic material remaining in the magazine chamber will move to the bottom o the magazine chamber 66 in proper alignment with the sleeve 20a, and the operator can again manipulate the slide 68 with his thumb to press the new lowermost block 24 in the magazine chamber 66 into the sleeve 20a and the melting chamber.
The present invention has now been described with reference to one embodiment thereof. It will be apparent to those skilled in the art that many change~ can be made in the embodiment described witllout departing from the scope of the present invention. For example, the device 60 2~i could incorporate the features described with reference to drawing Figures 6 and 7 of United States Paten-t 4,552,287. Also recesses 78 of the type illustrated could be used on the other sidewall defining the magazine chamber 66 instead of the spring fingers 77.
Thus the scope of the present invention should not be limited to the structures described in this application, but only by struc-tures described by the language of the claim and their equivalents.
.
Claims (3)
1. A device for dispensing molten, thermoplastic material comprising a frame including a handle positioned so that an operator can grip the handle with the fingers of one hand; a barrel member mounted on said frame and having an internal melting chamber communicating with an outlet opening through a nozzle; a sleeve with a through opening having one end secured to said barrel member with said through opening communicating with the end of said melting chamber opposite said outlet openings said sleeve being adapted to receive a block of solid thermoplastic material with one end portion of the block in the melting chamber and the block projecting through said sleeve; and means for heating said barrel member to melt the end portion of the block therein wherein said device further includes a magazine assembly at the end of said sleeve opposite said melting chamber comprising walls included in said frame and defining an open topped magazine chamber adapted to hold a stack of solid thermoplastic material blocks with the lowermost block in aligned end-to-end relationship with a said block of thermoplastic material in said sleeve, and a slide having an end surface adapted to engage the end of a said block opposite said sleeve, a shape adapted to replace the lowermost block in the stack, an upper surface adapted to support blocks in the stack on said upper surface, having a notch opening through its side opposite said upper surface adapted to receive the end portion of an operator's thumb, and being mounted on said frame for movement along a path generally aligned with the melting chamber (1) from a retracted position with the slide out of the magazine chamber and said end surface adjacent an end of the lowermost block; in the magazine chamber opposite said melting chamber (2) to an advanced position with said slide extending across the bottom of said magazine chamber to press the lowermost block in the magazine chamber toward the melting chamber by engagement between said end surface and the block and to support the other blocks in the magazine chamber on said upper surface, and (3) back to said retracted position to allow another block in the stack to move into alignment with the melting chamber, said notch being accessible by the thumb of an operator gripping said handle portion to afford manual reciprocation of said slide between said retracted and advanced positions by the operator.
2. A device according to claim 1 wherein said walls defining said magazine chamber comprise spaced opposed ledges defining a bottom wall for said magazaine chamber, and said slide has opposite longitudinal grooves receiving said ledges to afford reciprocation of said slide along said ledges between said retracted and advanced positions.
3. A device according to claim 1 wherein said walls defining said magazine chamber include spaced vertically extending side walls, and at least one of said side walls has a plurality of recesses parallel to the axis of the chamber along its inner surface, said recesses being spaced and adapted to partially receive the sides of blocks in a said stack of blocks in the magazine chamber to restrict the blocks from moving out the open top of the magazine chamber when the device is tipped on its side.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/456,346 US4552287A (en) | 1983-01-07 | 1983-01-07 | Thermoplastic dispensing device |
| US456,346 | 1983-01-07 | ||
| US57024584A | 1984-01-12 | 1984-01-12 | |
| US570,245 | 1984-01-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1229726A true CA1229726A (en) | 1987-12-01 |
Family
ID=27038197
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000471893A Expired CA1229726A (en) | 1983-01-07 | 1985-01-11 | Thermoplastic dispensing device with manually operated feed magazine |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1229726A (en) |
-
1985
- 1985-01-11 CA CA000471893A patent/CA1229726A/en not_active Expired
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| MKEX | Expiry |