US2804723A - Oscillating sanding machines - Google Patents

Description

Sept. 3, 1957 A. F. SWEENEY OSCILLATING SANDING MACHINES Filed Nov. 2, 1955 7 Shee'ts-Shee t l INVENTOR. ARMAND F. SWEENEY BY 2.9mm a? 01% Sept. 3, 1957 W N 2,804,723

OSCILLATING SANDING MACHINES Filed Nov. 2. 1955 7 Sheets-Sheet 2 N 3 g C) I Q m B W 3 Q 0' \r N O L Q N v II N Q 2% I, s Q & I n

KN) \X N 36 Q INVENTOR.

ARMAND F'. SWEENEY 7 Sheets-Sheet 3 Filed Nov. 2, 1955 INVENTOR.

ARMAND F- WEENEY Sept. 3, 1957 A. F. SWEENEY 2,804,723

OSCILLATING SANDING MACHINES Filed Nov. 2, 1955 7 Sheets-Sheet 4 FIG- 4- INVENTOR. ARM N'D F. SWEENEY R "imam 3%" p 3, 1957 A. E SWEENEY 2,804,723

'OSCILLATING SAND ING MACHINES Filed Nov. 2. 1955 7 Sheets-Sheet 5 ENTOR. ARMAND F. SWEENEY FIG- 6.

Sept. 3, 1957 A. F. SWEENEY OSCILLATING SANDING MACHINES Filed Nov. 2, 1955 7 Sheets-Sheet 6 INVENTOR.

ARM N 'F. SWEENEY Sept. 1957 A. F. SWEENEY 2,804,723

OSC ILLATING SANDING MACHINES Filed Nov. 2, 1955 7 Sheets-Sheet 7 FIG. 9.

' INVENTOR. ARMANI) F. SWEENEY nited States Patent OSCILLATING SANDENG MACHINES Armand F. Sweeney, Chicopee Falls, Mass. Application November 2, 1955, Serial No. 544,499 6 Claims. (Cl. l-38) It is an object of this invention to provide a sanding machine that will finish the wood or object to be polished completely in one operation on one surface.

It is yet another object of the within invention to provide a sanding machine that is simple to manufacture and inexpensive in the costs of operation.

It is another object of the invention herein to provide sanding drums that oscillate over the surface of the wood being polished.

It is yet another object of the within invention to provide a self contained endless bed for feeding the wood through the operating surfaces.

It is another object of the within invention to provide means for adjusting both the distance between the sanding drums and the endless bed as well as the distances between the bottom of the drum and the top of the wood being polished.

It is still another object of the within invention to elimimate the jamming and slipping of the wood to be polished.

And another object of the invention is to provide a sanding machine that conserves the sandpaper in use.

A series of sanding drums are mounted within pressure bars which are sufficiently spaced apart to allow the sur faces of the sanding drums to protrude over an endless bed that feeds the stock. The pressure bars each have a fine adjustment for positioning the surfaces of the sanding drums at various levels with respect to the pressure bars. Because of this feature of a micrometric adjustment, it is possible to adjust the sanding drums to a predetermined level so as to remove from the object to be polished a predetermined amount of stock. This adjustment is figured independent of the speed of the sanding drums and the type of sanding paper in use which are essentially constants. There are individual motor drives for moving the endless beds and for moving the sanding drums in an oscillating motion back and forth laterally over the wood being polished. This oscillating action removes snake marks from the wood. The endless bed ties have rubber surfaces with indentions therein that prevent the slipping of the wood as it passes beneath the sanding drums. This arrangement enables stock as short as 4 inches to be sanded and polished efliciently.

These and many other objects may be better understood by reference to the following detailed description of the device in which:

Figure 1 is an end view of the machine.

Figure 2 is a side view of the machine looking toward the right of Figure 1.

Figure 3 is the other side view of the machine looking toward the left of Figure 1.

Figure 4 is a top view of the device looking down on Figure 1, but with the pulley system to the left.

Figure 5 is a bottom view of the device looking up into the machine shown in Figure 1.

Figure 6 is a side elevational view of the super structure that houses the sanding drums, showing in detail the adjustments that can be made. 7

Figure 7 is a top perspective view of the superstructure of Figure 6 showing the features within the sanding drum housing.

Figure 8 is the end view of the Figure 1.

Figure 9 is a side view of the machine showing the endless bed raising and lowering mechanism.

Figure 10 is a perspective view of an endless bed tie.

For a better understanding and a more coherent disclosure, because of the many details of the machine, it will be more expeditious to explain the various component parts in each figure separately.

FIGURE 1 Figure l, which is an end view, discloses at the left hand side an oscillating motor which is mounted on the oscillator motor support 2. The motor 1 does not itself oscillate but causes its load to oscillate as will be hereinafter explained. For the sake of clarity it will be referred to as the oscillating motor. A side panel which is only shown in end view is designated as 3. At the top of the side panel 3 is a horizontal rail 4. This rail is substantially U-shaped in section, and runs down the length of the device. Rail 4 is on both sides of the machine as is the side panel 3. There is also a vertical rail 5 which is secured to the horizontal rail 4. The vertical rail 5 is also on each side of the machine.

At the bottom of the machine is a lower end horizontal rail 6 which is also U-shaped in section with the open portion facing the viewer. Mounted crossways from the side panel 3 is a table raising and lowering bar support designated as7. A transmission shaft 8 runs below the bar support 7. This shaft 8 is known as the table raising and lowering transmission shaft. Mounted on this shaft 8 is a left pinion or bevel gear 9 and at the other end a right pinion gear 10. In the middle of the shaft is a transmission shaft pinion gear 11 which meshes with a transmission pinion gear 12. At each end of the vertical rail 5 are mounted bearing supports 14. Atop these hearing. supports 14 are the adjustable bearing supports 45. Inside of the adjustable bearing supports 45 are the set screws for locking the adjustable bearing supports'indicated as 13. Interconnected with the bearing support 45 is an endless bed drive shaft 15. Mounted on the endless bed drive shaft are the sprockets 16a about which the endless bed chain 16 moves. Mounted on the endless bed chain 16 are the endless bed ties 17, which comprise a rubber portion 17o. An endless bed frame member 19 is mounted along the vertical rail 5. Mounted atop the endless bed frame member is the endless bed panel indicated as 18. Rail 19 is secured longitudinally from each of the vertical rails 5. The bolt 20 secures the side panel 3 to the horizontal rail 4.

On the right side of Figure l is the driving assembly for the endless bed. A drive shaft sprocket 21 is mounted on the endless bed drive shaft 15. An endless bed drive pulley chain 22 is mounted on top of the drive shaft sprocket 21. It also is mounted on top of the take-up sprocket 23 which is supported on the take-up support bar 23a. At the bottom of the pulley chain 22 is an idler sprocket 24 which is mounted on the idler sprocket bar 25. For a more complete understanding of the drive shaft.

device opposite from can be seen on the right side of Figure l. A belt from the motor ZScircumscribes a three step pulley 29 (see Pa a FIGURE 2 Reference is now made to the side view indicated as Figure '2 which is'a view looking toward the right side of Figure l. The numerical designations in Figure 2 are, ofcourse, similar to those in Figure 1. In addition to those elements already noted, a vibration take-up for the endless bed is indicated as the sprocket Wheel 31. This is to prevent slack in the endless bed so that the endless bed will run smoothly. 'A rail guide for the endless bed chain 22 is designated by the numeral 32 and is located just below the endlessbed chain.

As stated before, the pulley 29 comprises three different sections indicated as 2 9, 29a and 29b. The belt 30 is mounted on the middle section 2911 in the drawing. These various size pulleys obviously control the speed of motion of the endless bed. 011 the far right side of Figure 2 at the far end of the endless bed is an endless bed bearing 33. This'hearing 33 is'mounted in front of the endless bed bearing support 34.

. A motor is designated by the letter M. Mounted on the drive pulley of this motor is a belt 35. This belt 35 circumscribes a pulley 38 which is mounted on a sanding drum. (See Figure 4.) Connected to pulley 38 which comprises two sections is a belt which circumscribes a pulley 37. Pulley 37 is also in two sections and mounted on its other section is a belt 39 which circumscribes the pulley 36. Hereafter belt 40 shall be referred to as the middle drum belt, belt 39 as the rear drum belt, and belt 35 as the drum driving belt. The pulleys 36, 37, and 38 are mounted between the pressure bar supports 41. In these pressure bar supports '41 are'the elongated slots 42. Mounted within these'elongated slots 42 by means of bolt assemblies are the adjustable bars 43 (see Figure 7): At each end of the superstructure containing the pulleys 36, 37 and 38 are the side pressure support members 44.

FIGURE 3 Reference is now made to Figure 3 which is a view looking at the left side of Figure l. 1

The oscillator motor assembly 1 has a drive shaft 48 extending to the left of it in Figure 3. This oscillator motorshaft 48 enters a shaft coupling 49 which is connected to a shaft 50 that runs almost the complete length of the machine. A hearing shaft support 51 is mounted on a support bracket 52. Within this bearing shaft support 51 passes the shaft 50. The dimensions of the hearing shaft support 51 are such that the shaft 50 will rotate within it. Mounted on the shaft 50 are the eccentries-53 which are part of the oscillating circuit. These eccentrics 53 are within the eccentric bearings 54. Eccentric bearings 54 are connected to the forks 56. These forks 56 have the bifurcated arms 55. Mounted within the bifurcated arms 55 are the sanding drumshafts 60. The -forks 56 are mounted on the member support brackets 57. Y V

The fork 56 has in its arms 55 an elongated slot 90 through which the bolt 91 passes. Bolts 91 support the thrust collars 59. The elongated slot 90 is for vertical adjustment of the sanding drums and enables the height of the collars 59 to be raised or lowered by the setting of the bolt 91; i

'-At the extremeleft end in Figure 3 of the shaft 50 is a collar 58 which prevents longitudinal motion of the shaft 50.

Mounted on the sanding drum shaft 60 and between the bifurcated arms 55 of the fork 56 are the oscillating thrust collars 59. At the lower left side of Figure 3 can be seen a circular shaped crank 63 which controls the adjustments of the endless bed as will be explained hereinafter.

FIGURE 4 Reference is now made to Figure 4 which is a view looking down on the top of Figure 3 and Figure 2.

In addition to those elements already disclosed in the previous figures, certain features that were hidden behind the other views can now be explained.

The endless bed shaft bearing 45 is seen in this view in detail. It comprises the adjustment for the endless bed chain 46 and the rotatable bolt or set screw 47.

Mounted on the sanding drum shaft 60 are bearings 61 for the drum shafts 60. The bearings 61 maintain the drums 36a, 37a, and 38a in a fixed position on the shafts 60. The pressure bar adjustment plates are also in view for the first time and are indicated as 43. The pressure bars 62 interconnect the pressure bar supports 41. The end pressure bar 82 can be seen in more detail in Figure 7 and will be explained under that heading. The pressure bars 84 press the work down onto the endless bed as later explained.

FIGURE 5 Reference is now made to Figure 5 which is a bottom view looking up into the device. It is a view looking up into the bottom of Figure 4. The longitudinal bot tom frame members 64 are connected to the bottom latitudinal frame members 65. Connected to the table bed adjusting wheel 63 is a drive shaft 70. Mounted on this drive shaft is a pinion, or beveled gear 71, hereinafter called the drive shaft pinion gear 71. This drive shaft pinion gear 71 meshes with a drive shaft pinion gear 72 which is connected to and rotates the elevational shaft 73 (see Figure 9). The numeral 74 is employed to indicate a threaded stud which engages the endless bed table raising screw 86 as will be explained in the description under the heading of Figure 9.

Also mounted on the drive shaft 70 is another pinion gear 69 which is also a drive shaft pinion gear. This gear 69 meshes with the transmission shaft pinion gear 68. The transmission pinion gear 68 is at the end of the table bed longitudinal drive shaft 66. This drive shaft 66 is mounted a short distance from the pinion gear 69 by a shaft transmission support 67. It is also mounted at its far end (right side) by another shaft transmission support '67. At its far end (right side)'transmission shaft 66 has mounted a transmission shaft pinion gear 12, which'was referred to in the explanation of Figure l. Meshing with pinion gear 12 is a pinion gear 11 which is mounted on shaft 8 Also mounted on shaft 8 are the pinion gears 9 and 10. Thesepinion gears 9 and 10 rotate gears 72a and '10 which are mounted on elevational shafts that are similar to shaft 73 but cannot be seen in this view. a

A better understanding of these transmission members may be had by reference to the description of Figure 9, and the operation ofthe table raising and lowering mechanism.

FIGURE 6 Reference is now made to Figure 6 which is a view of the superstructure shownin the side views of Figures 2 and 3.. That is to say, it is the structure in detail that contains the sanding drums. Essentially Figure 6 is an exploded view to show the details'of adjustment that can be made tojcontrol the position of the drums 36a, 37a, and 38a. .A time thread adjustment screw 78 is mounted in a threaded uppersupport 80. At the bottom of this screw are lock pins 81. These lock pins 81 extend into the bottom support 79. Lock pins 81retain the screw 78 within the bottom support 79. Q

It is to be noted that the other elements. have already been discussed and the detailed explanations of Figures 2 and 3 and the details ofstructure are more clearly brought out here in Figure 6.

The fine thread adjustment screws 78a are mounted in the upper support member 80a which are bridged between the pressure bar supports 41 above the sanding drums 36a, 37a, and 38a. The adjustment screws 78:: extend into a bottom support 79a, for the screw 78a, which is also bridged between the pressure bar supports 43 below 80a. Lock pins 81a retain screw 78a within the bottom support 79a. 7

The fine thread adjustment screw 78b is mounted in an upper support bracket 80b which is bridged between the two pressure bar support members 62. The bottom of the screw 78b is journaled in a lower bracket 79b similarly to the Way screw 78 is set within bracket 79. That is to say that a pin 81b locks the screw 78b within the bracket 7% and yet allows it to be rotated as will be explained hereinafter. The pins 81, 81a, and 81b swivelly connect the screws 78, 78a, and 78b, respectively, to the brackets 79, 79a, and 79b, respectively.

The brackets 79 may be bolted or welded to the adjustment plate 44. The bracket 79a is similarly secured to the pressure bar adjustment plate 43. The bracket 79b is also similarly secured to the pressure bar adjustment plate 62. The explanation under the heading Setting the machine for operation will bring out the exact function of the micrometer thread adjustment screw 78.

FIGURE 7 Figure 7, which is the top view looking down into the superstructure of Figure 6, shows one of the sanding drums removed. It can be easily seen that the end pressure bars 82 are L-shaped. The middle pressure bars 84 are also L-shaped. That is to say that they have flat horizontal surfaces at right angles to their vertical surfaces. Between the bottom of the pressure bars are openings 88 which enable the lower portion of the sanding drums 36a, 37a, and 38a to contact the surface of the wood to be polished.

FIGURE 8 The view of Figure 8 is the opposite end from the view of Figure 1. Each of the component parts shown in this view have been described in the discussion of the other figures.

FIGURE 9 Because of the inability to teach the details of the endless bed lowering and raising mechanism from the bottom view of Figure 5, it was felt that Figure 9 showing the actual engagement of the moving parts of the transmission system with the endless bed chassis would more expeditiously teach this important feature of the invention. The elevational shafts 73 have at their bottoms, the elevational shaft pinion gears 72 and 72a. It is to be noted that the elevational shafts 73 have the threads 86 which engage the studs 74. The studs 74 are mounted in the endless bed rail 19. The drive shaft 70 shown in Figure 5 having at one of its ends a pinion gear 71 is mounted in a bracket 87. There is a similar bracket 87 for each of the drive shafts, 70 and 8.

FIGURE 10 The ties 17 of the endless bed have a rubber pad sur' face 17a which have half moon shapes 17b. These half moons 17b are indentations and are for creating a suction so that the wood which is setting on the rubber surface 17a will not slip as the endless bed moves beneath the sanding drums. The bottom portion of the tie 17 is made of an alloyed truss steel.

Setting the machine for operation ADJUSTMENT OF THE SANDING DRUMS The first step is to adjust the sanding drums 36a, 37a and 38a to the proper levels in the space '88 (see Figure cured to it the bracket 79. The inside of the upper bracket 88 is threaded. With respect to bracket 80, the pressure bar 44 may be moved closer or further away as adjustment screw 78 is turned. Assuming that the drum 38a has been properly positioned, the lowering or raising of the pressure bar 44 will determine in part the amount of stock that will be removed from the wood by the sanding paper on drum 38a.

The sanding drum 38a has an adjustment plate 43 to which is afiixed the lower bracket 79a. The lowering or raising of the adjustment plate 43 will control the height of the drum 38a. In other words, the turning of the adjustment screw 78a will force the adjustment plate to go up or down in the slots 42 bringing with it the sanding drum 38a. The adjustment of the height of the sanding drum 38a will also partially determine the amount of stock to be removed from the wood by the sanding paper on drum 38a.

There is a certain amount of resiliency because of the rubber 17a on the ties 17 of the endless bed. The height of the pressure bars 84 and 82 as well as the height of the sanding drums 36a, 37a and 38a in the openings (see 88 in Figure 7) exert a pressure on the wood travelling on the ties 17a. The surface of the ties 17a, being of rubber and creating a suction with the lower surface of the wood, prevent the wood from slipping as the drums 36a, 37a and 38a rotate over its upper surface.

The adjustments for each of the sanding drums 36a, 37a and 38a are performed in the same manner although the heights of the respective pressure bars 82 and 84 proximate the respective drums, are varied since the thickness of the wood is less after it has passed beneath a drum.

THE RAISING AND LOWERING OF THE ENDLESS BED In order to follow this portion of the specification, ref erence is made principally to Figure 9 along with Figures 1, 5 and 8. 7

Because the wood to be sanded and polished may vary in size, it was necessary to design the machine so that wood of both small and large sizes can pass over the endless bed.

A wheel 63 is integral and mounted on a shaft 70. Also on shaft 70 are the pinion types gears 69 and 71. Upon the operator rotating wheel 63, shaft 70 rotates causing the gears 69 and 71 to rotate. Meshing with the gears 71 are the separate gears 72 and 75, respectively. Both of these gears rotate causing the shafts 73 and 76, respectively, on which they are mounted to rotate. The upper portion of the shafts 73 and 76 are threaded as indicated by the numeral 86. The endless bed rail 19 has at its bottom flange a threaded opening 74 into which the threaded portion 86 of the-shafts 73 and 76 are threaded. As the shafts 73 and 76 rotate, the rail 19 moves upon or down depending on the direction of rotation. Since the entire endless bed assembly is mounted about the rails 19, as rail 19 moves so will the endless bed assembly, which, of course, comprises the chain 16, sprocket 16a as well as the ties 17.

The gear 69 causes the gear 68 (Figure 5) to rotate. Shaft 66 on which gear 68 is mounted rotates with gear 66. Gear 12 which is mounted on shaft 66 rotates and meshes with gear 11 which is mounted on shaft 8. Shaft 8 rotates its gears 9 and 10. Gears 68a and 72a mesh with gears 10 and 9 respectively and rotate when 10 and 9 rotate. Gear 72a is mounted on shaft 73a and 73a rotates with 72a. Like shaft 73, shaft 73a is threaded at 86 and is within an opening 74 in the rail 19.

Gear 68a is mounted on shaft 76a and 76a rotates with 68a. Like shaft 73 shaft 76a is threaded at 86 and is within an opening 74 in the rail 19.

When shafts 76a and 73a rotate, the rail 19 will move THE POLISHING OF ONE WOOD PIECE Once the machine has been set up so that the endless bed is at the proper level for the size of the wood to be polished and once the sanding drums have been properly leveled to remove the amount of stock desired, the various motors 1, M, and 28 may be energized.

THE OSCILLATING MOTION The motor 1, which is the oscillating motor (see Figures 3 and 4), rotates the oscillating motor shaft 48. The shaft 48 is coupled to the shaft 50 by the coupling 49. Shaft '50 rotates with shaft 48. The shaft 50 passes through the eccentrics 53 and the eccentric bearings 54. As shaft50 rotates, it causes the eccentrics 53 to actuate the bifurcated arms 55 and fork 56 and they (55 and 56) move back and forth toward the sanding drums in an oscillating motion. The shafts 60 of the sanding drums 36a, 37a and 38a are connected with the oscillating fork thrust bearings 59 which are mounted between the arms '55. Accordingly, shafts 60 are moved back and forth with the forks 56 causing the drums 36a, 37a and 38a to move back and forth in an oscillating motion. It is to be noted that the motor 1 used in the embodiment herein is of the ratio type for reducing the speed of rotation.

A mechanical advantage system of the proper size that slows down the speed of rotation and increases the power would be within the spirit of this invention. It is important to appreciate that on some types of wood the speed of oscillation should be increased and others decreased. The gears in the ratio motor may be used for controlling this speed of oscillation. The better practice is to change the size of the pulleys. As stated previously, this oscillating motion removes the snake marks from the wood.

ROTATION OF SANDING DRUMS In Figures 2 and 4, there is shown the best views for understanding the operation of the sanding drums 36a, 37a and 38a.

'A motor M has connected to its drive shaft (not shown) a belt 35. This belt 35 is connected with one section of the pulley 38. The other section of pulley 38 has a belt 40 circumscribing it. The belt 40 is connected to one section of the pulley 37. Pulley 37 has circumscribing it a belt 39 which is connected to pulley 36. When the motor M is energized, the pulleys are operated by the respective belts that impart rotation thereto. Since the drums 36a, 37a, and 38a are mounted on the shafts 60 which are connected to the pulleys 36, 37 and 38, the drums 36a, 37a, and 38:: also rotate with the rotation of the pulleys. The bearings 61 maintain the drum shafts 60 steady and firm in the pressure bar supports 41.

OPERATION OF ENDLESS BED The endless bed which comprises the ties 17 and the chains 16 is operated under the energy taken from the motor 28 which drives the ratio motor or mechanical advantage system 27 by means of the drive belt 30 which is mounted on a triple section pulley 29. (In Figure 2 it is on the middle section 29a.)

The chain 22 is connected to a sprocket driven by the ratio motor 28. This sprocket is not shown in the drawings, but is connected to the drive shaft of the ratio motor 27 The chain 22 passes over a take up sprocket 23 which is mounted in the side panel 3, over the endless bed drive shaftsprocket 21, which .is mounted on the endhas bad ri shaft C ain a passes e t idler sprocket 24 which is also mounted on the side panel 3. When the chain 22 moves, it rotates the endless bed drive shaft 15. Mounted on 15 are the sprockets 16a for the endless bed. As 15 rotates so also do the sprockets 16a. The chains 16 of the endless bed assembly rotate moving along-the ties 17 which are mounted thereon. Thus the endless bed rotates.

At the right end of Figure 2 and Figure 8 can be seen the front endless bed bearing 33 which retains the shaft 33a at this end of the endless bed. On shaft 33a are the sprockets 16b which are rotated by the chains 16.

The piece of wood to be sanded is passed beneath the drums 36a, 37a, and 38a on top of the ties 17 of the endless bed assembly. The drums have sanding paper or abrasive surfaces of various textures usually coarse, medium and fine in that order. This abrasive surface is rotated over the wood by the drums 36a, 37a, and 38a and is also passed laterally back and forth in an oscillating motion. The speed of the endless bed, the velocity of oscillation and rotation of the drums, the height of the endless bed with respect to the surface of the drums, all being variable, enable the operator of the machine to completely finish and polish one surface of the wood as it passes on the endless bed from one end of the machine to the other.

The fact that there are so many variables makes it easy for the operator to adjust the machine to get the best performance. The speeds of all the moving parts may be altered or varied. The speed of the motor 28 whose energy is used to drive the endless bed assembly is varied by changing pulleys. The oscillating speed is similarly controlled by changing the pulley (not shown) of the motor 1. The speed of the rotating drums 36a, 37a, and 38a may be similarly controlled by the change of pulleys (not shown).

The dust from the wood that is being sanded is retained in a housing covering the superstructure of Figure 6. It is connected to a suction system and is carried away.

I claim:

1. A sanding machine comprising at least two sanding drums having abrasive material covering their surfaces, a fine adjustment means for controlling the abrading action of said sanding drums, said adjustment consisting of a fine thread adjusting screw, a separate threaded upper support located above and near the ends of each of said drums, a separate said thread adjusting screw mounted in each of said supports, a separate lower support beneath each of said screws, said screws being engaged therein, pressure bars proximate the drums, each of said lower supports integral with a separate said pressure bar, whereby a rotational movement of said screw transmits a vertical movement to said pressure bar, an endless bed assembly beneath said sanding drums, said endless bed assembly having a pair of parallel chains connected to each other by a plurality of ties, said chains and ties mounted at each end by sprockets, said sprockets integral with shafts at each of said ends, a chassis for the endless bed assembly, said shafts supported by said chassis, a system of transmission shafts and gears for raising and lowering the said chassis, means connected to one of said sprocket shafts for imparting motion thereto whereby said endless bed moves continuously about said sprockets.

2. A sanding machine comprising a plurality of abrading drums, fine means for controlling and positioning the elevation of said drums, a movable endless bed, a chassis for said endless bed, a plurality of vertical shafts adjustably engaging said chassis, gears at the lower ends of each of said shafts, a separate gear on a horizontal shaft meshing with each of said first mentioned gears, a transmission system for synchronously rotating said horizontal shafts whereby the said chassis is raised and lowered, means for rotating said drums, means for oscillating said drumsand means for moving said endless bed.

3. VA sanding machine comprising, atleast two sanding drums having abrasive material covering their surfaces, a fine thread adjusting screw, a separate threaded upper support above and to the side of each of said drums, a separate said thread adjusting screw mounted in each of said supports, a separate lower support beneath each of said screws, said screws being engaged therein, pressure bars proximate the drums, each of said lower supports integral with a separate pressure bar, whereby a rotational movement of said screw transmits a vertical movement to said pressure bar, means for rotating the drums, a movable endless bed beneath the said drums, an oscillating means, means for transmitting oscillations from the said oscillating means causing said sanding drums to move back and forth laterally over the endless bed, and means for raising and lowering the endless bed.

4. A sanding machine comprising a plurality of rotating drums, said drums having secured thereto abrasive surfaces, vertical support members on each side of said drums, drum shafts secured to said support member and passing within the said drums, fork means mounted on one side adjacent to each of said drums, a thrust bearing interconnecting said fork means and said shaft, a separate longitudinal shaft connected with each of said fork means, means for oscillating said shafts whereby said drums oscillate back and forth in the direction of the said drum shafts, a plurality of fine thread adjusting screws, a separate threaded upper support above and to the side of each of said drums, a separate said thread adjusting screw mounted in each of said supports, a separate lower support beneath each of said screws, said screws engaged therein, pressure bars proximatethe drums, each of said lower supports integral with a separate pressure bar, whereby a rotational movement of said screw transmits a vertical movement to said pressure bar.

5. A sanding machine comprising a plurality of rotating drums having abrasive surfaces, fine adjustable means for raising and lowering said drums, said means consisting of a plurality of a fine thread adjusting screw, a separate threaded upper support above and to the side of each of said drums, a separate said thread adjusting screw mounted in each of said supports, a separate lower support beneath each of said screws, said screws engaged therein, pressure bars proximate the drums, each of said lower supports integral with a separate pressure bar, whereby a rotational fine movement of said screw transmits a vertical fine movement to said pressure bar, a shaft within each of said drums, fork means having bifurcated arms, thrust collars on said shafts interconnected with said fork arms, and means for transmitting oscillating motion to said drum shafts, consisting of a motor, eccentrics, a transmission shaft for imparting rotary motion from said motor to said eccentrics, a separate eccentric interconnecting said drive shaft and a separatefork causing said shafts within the drums to oscillate longitudinally as said shaft rotates.

6. A sanding machine as recited in claim 5 including an endless bed located beneath said drums, a chassis for supporting said endless bed, a raising and lowering wheel for said chassis, a rotatable transmission shaft connected to said wheel, three pinion gears mounted on said shaft, two of said gears meshing with pinion gears on vertical shafts, the other of said gears meshing with a gear on a longitudinal shaft, said vertical shafts adjustably connected with said chassis, said longitudinal shaft interconnected with a shaft substantially parallel to said first mentioned transmission shaft, this latter shaft having two pinion gears mounted thereon and meshing with pinion gears on other vertical shafts adjustably connected to said chassis whereby when wheel is rotated the vertical shafts are rotated causing said endless bed to be raised or lowered.

References Cited in the file of this patent UNITED STATES PATENTS 444,155 Swift Jan. 6, 1891 657,357 Perry Sept. 4, 1900 1,618,207 Lane Feb. 22, 1927 1,653,741 Solem Dec. 27, 1927 1,862,671 Field June 14, 1932

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