GB2132968A - Multi-axis manipulator - Google Patents

Abstract

A multi-axis manipulator is disclosed which may be utilized to effect the transfer of a workpiece between a series of work stations such as for example plurality of presses. The apparatus is specifically designed for high speed production operation and employs the capability to selectively impart revolving, rotating, vertically translating and horizontally translating movement to the workpiece depending upon the system's constraints. A single barrel cam (20) is provided from which multiple cam followers (52,82) are actuated to impart portions of the desired movements. Additionally, the apparatus is reversible so that production flow may proceed in either direction. <IMAGE>

Description

SPECIFICATION Multi-axis manipulator The present invention relates generally to work transfer apparatus and more specifically to extremely high speed multiple axis transfer apparatus designed to effect the transfer and/or reorientation of workpieces between successive work stations.

In many manufacturing operations, it is necessary to transfer a workpiece through several stations with various types of operations being performed thereon at each location. During the time required to effect this transfer the operation performing means remain idle thus limiting the rate of production.

Additionally, the operation performing means often impose sever constraints on the ability of the transfer apparatus to accomplish its objectives such as for example the positioning of support or guide structure, tooling design constraints, etc.

Another problem often encountered is that the same group of operation performing means may be utilized to make more than one particular part. For example, a series of presses may all be utilized to progressively form a first part whereas only a portion of the same series may be required to form another part. Rather than allow the remaining machines to set idle, it is preferable to utilize them to manufacture yet a third part. However, because of physical space restrictions, it may be difficult to supply workpieces at a point intermediate the line of operation performing apparatus. Thus, the transfer apparatus should preferably be reversible so as to enable the workpieces to be fed in either direction through the series of machines and further should be easily changed over to accommodate for the differing part movements required.Additionally, it is important in such applications that the transfer apparatus be compact so as to enable it to be positioned to allow easy and free access to the operation performing means such as for changing of tooling or the like.

The present invention provides an extremely reliable positive acting multi-axis transfer apparatus which is particularly well suited for use in multistation manufacturing operations such as for example high speed progressive forming operations or the like. The apparatus includes a pair of arms positioned approximately perpendicular to each other. A cam drive arrangement is operative to extend the arms into an adjacent work station whereupon a partially formed part is grasped, raised and withdrawn from the station whereupon the arms are indexed to transfer the part to an adjacent idle station or the like. The other arm follows a similar sequence grasping another partially formed part from the idle station and placing it in the next adjacent work station.In order to offer maximum flexibility, the apparatus is designed to be operated in both a "forward" or "reverse" direction. When arranged in alternating position with a series of forming apparatus, it is possible to run one part through all the forming machines and also be able to thereafter run two parts requiring a lesser number of forming operations in opposite direction simultaneously with only a very minimal amount of changeover required. Additionally, the transfer apparatus is designed to angularly re-orient the part during the indexing operation should the particular operation require same. As mentioned previously, the apparatus is particularly designed for high speed production and is capable of fully cycling within 1.875 seconds.

Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.

Brief description of the drawings Figure 1 is a schematic plan view of a manufacturing line showing the alternating positioning of a multi-axis manipulator and associated manufacturing equipment in accordance with the present invention; Figure 2 is a fragmentary plan view shown partially in section of the present invention, the section being taken along line 2-2 of Figure 3; Figure 3 is a fragmentary side elevational view of the multi-axis manipulator apparatus shown in Figure 1 with portions thereof being broken away and shown in section; Figure 4 is another side elevational view with portions thereof being broken away similar to that of Figure 3 but showing the multi-axis manipulator shifted 90 .

Figure 5 is a fragmentary plan view of the present invention showing the arm assembly with portions thereof broken away; Figure 6 is an enlarged fragmentary detail view of the multi-axis manipulator showing one of the gripping arms in a first operating mode all in accordance with the present invention; Figure 7 is a view similar to that of Figure 6 but showing one ofthe gripping arms in a second operating mode; Figures 8a, b, and c are a schematic diagram showing the operating motion sequence by which the gripping arms are first extended and then maintained in the extended position while being elevated in accordance with the present invention; Figure 9 is a graphic representation of a manufacturing cycle showing both the manufacturing and transfer operation;; Figure 10 is a graphical representation of the various portions of the transfer operation all in accordance with the present invention; Figure 11 is a fragmentary view shown in perspective of another embodiment of the multi-axis manipulator in accordance with the present invention; Figure 12 is a fragmentary plan view of the embodiment shown in Figure 11; and Figure 13 is a fragmentary side elevation view of the embodiment of Figure 11 with portions thereof being shown in section.

Description of t}- 9 preferred embodiments Referrings now to the drawings and in particular to Figures 1-5, there is shown a multi-axis manipulator in accordance with the present invention indicated generally by reference number 10. As best seen with reference to Figure 1, it is contemplated that a series of multi-axis manipulators 10 will be positioned midway between and along the centerline line of the working area of a series of operating machines such as for example a series of forming presses 12. In the exemplary arrangement shown, a series of six presses 12 are arranged in aligned side by side relationship with a destacker 14 positioned at each end of the series. Destackers 14 serve to feed blanks to the first manipulator 10 which will transfer the blanks into the adjacent press 14.A series of seven manipulators 10 are positioned in alternating relationship therewith and will operate to sequentially transfer a workpiece between successive presses 12.

An idle station 16 is also provided being positioned directly in front of each of the manipulators 10. Idle stations 16 serve as a holding location for partially formed parts, It should be noted that as shown presses 14 are of the tilting variety and completed workpieces exitthereform from the rear being deposited in a suitable bin, conveyor, or the like.

Other arrangements may be equally feasible.

Manipulator 10 may be segregated for descriptive purposes into three major portions, those being the drive assembly 18, actuating assembly 20 and arm assembly 22 all of which are supported upon a common supporting base 24 of a shape and size suitable to enable it to be positioned midway and along the centerline of the manufacturing apparatus 12.

Drive assembly 18 comprises a barrel cam 26 drivenly connected to a clutch/brake gear reducer 28 which in turn is drivenly connected to a reversible electric driving motor 30. Barrel cam 26 has provided thereon three cam grooves 32,34,36, each of which is circumferentially continuous and operative to provide a full operational cycle for each 360 of revolution of the barrel cam 26. It should be noted that if desired clutch/brake gear reducer 28 may alternatively include means for reversing the direction of rotation of cam 26 thereby eliminating the need for a reversible motor 30. Alternatively, if reverse operation capability is not needed for the particular application, there is no need for either a reversible motor or reverse capability in gear reducer 28.

An elongated torque tube 38 is positioned below the end 40 of the barrel cam 26 immediately adjacent the clutch/brake gear reducer 28, being rotatably supported at opposite ends thereof by suitable bearing means. A crank arm 42 is secured thereto and extends upwardly alongside of barrel cam 26. A cam follower 44 is secured to the end of crank arm 42 and is positioned within a first one of the cam grooves which we shall identify as the vertical lift grooves 32. A pair of crank arms 46,48 are secured in spaced relationship adjacent the other end of torque tube 38 being angularly displaced from crank arm 42 approximately 90 . Suitable rollers 50,52 are secured to the outer ends of each of crank arms 46, 48 in facing relationship and are received within an annular groove 54 provided on cylindrical tube 56.

A second elongated torque tube 58 extends below the other end 60 of barrel cam 26 being positioned in generally parallel spaced relationship to torque tube 38 and is also rotatably supported at opposite ends thereof by suitable bearing means. Torque tube 58 also has a crank arm 62 secured thereto extending upwardly alongside barrel cam 26 adjacent end 60 thereof. A cam follower 64 is secured to the upper end thereof and is positioned within a second of the cam follower grooves which we shall identify as the extension drive groove 34. A pair of crank arms 66, 68 are also secured to torque tube 58 in slightly spaced relationship adjacent the other end thereof and are angularly displaced from crank arm 62 approximately 180 .

A suitable roller member 70 is positioned between and supported by the other ends of crank arms 66, 68, roller 70 being received within an elongated slot 72 provided in a crank arm 74 secured to a third relatively short torque tube 76. Torque tube 76 is positioned directly below and in substantially axially parallel vertically aligned relationship with torque tube 58. A second pair of crank arms 78,80 are secured to torque tube 76 in axially spaced relationship and are angularly spaced from crank arm 74 approximately 904 The outer ends of crank arms 78, 80 are also each provided with suitable rollers 82,84 positioned in opposed facing relationship and are received within an annular groove 86 provided on the lower end of a shaft 88.While it may be possible to eliminate torque tube 76 and the associated crank arms 74, 78, and 80 and provide a direct operational coupling between crank arms 66, 68 and shaft 88, this wou Id require substantially greater free area to accommodate the swing of an elongated crank arm.

Hence, the use of a second torque tube 76 as thus described offers the advantages of a significantly more compact design.

A gear segment 90 positioned in a generally horizontal plane is rotatably supported on the base 24 and includes an arm portion 92 extending below barrel cam 26 and a gear toothed portion 94 extending outwardly in the opposite direction. In a preferred embodiment, gear toothed portion 94 is required to rotate through approximately 45' thus toothed portion 94 extends over an arc of approximately 60 (providing a 7 safety factor at either end) although a greater or lesser arc may be provided as necessary.

Secured to and extending upwardly from arm portion 92 is a third cam follower 96 which is received and driven by a third groove 36 provided on barrel cam 26. This third groove shall be identified as the index groove 36.

The actuating assembly 20 comprises an outer cylindrical vertically extending tube 56, the lower end of which has an annular groove 54 provided on an enlarged diameter portion thereof and is defined by upper and lower radially outwardly extending annular flanges 98, 100. Arm assembly 22 is supported on and non-rotatbly secured to the upper end of tube 56. Tube 56 is designed to be rotatably driven by means of a gear 102 which is rotatably supported on lower bearing assembly 104 secured to the supporting base 24. A plurality of elongated pin members 106 are secured to and project axially upwardlyfrom gear 102 through openings 108 in the enlarged diameter portion of tube 56.Suitable ball bushings 110 are provided within openings 108 so as to enable vertical movement of tube 56 with respect to gear 102 while maintaining the driving relationship therebetween.

Gear 102 is positioned in meshing engagement with gear segment 90 and thus will operate to rotatably drive tube 56. In a preferred embodiment, gear segment 90 will have a diameter twice that of gear 102. Thus, to effect a rotation to tube 56 through a 90 arc, gear segment 90 will be required to move only through a 45^ arc. This step up drive arrangement enables the use of a smaller barrel cam 26 and direct mounting of cam follower 96 on the arm extension 92 of gear 90 thereby avoiding the need for other complex linkage or a larger more cumbersome and costly barrel cam in order to reduce the chordal effects.It should be noted that a higher gear ratio may be used which would further reduce the required length and hence also the required diameter of the barrel cam 26 although this would increase the stresses on the cam follower and other drive components.

Tube member 56 is rotatably supported by an elongated generally cylindrically shaped collar member 112 having a pair of diametrically opposed outwardly extending arms 114,116. Depending from and secured to the outer end of each of the arms 114, 116 are cylindrical guide tubes 118, 120 each of which is telescopically received within a housing 122, 124 extending upwardly from the supporting base 24. Preferably a pair of suitable axially spaced ball bushing orthe like will be provided within each of the housings 122, 124 to provide the desired stability as well as to allow free vertical telescopic movement of the guide tubes 122, 124 therein. As best seen with reference to Figure 4, housing 124 is positioned coaxially with and extends upwardly from base 24 through an opening 126 in gear segment 90.

A radially outwardly extending axially upwardly facing shoulder 128 is also provided on collar member 112 intermediate the ends thereof upon which a bevel gear 130 issupportinglysecured.

Bevel gear 130 is non-rotatably mounted and de signed to mesh with another bevel gear 132 forming a part of the arm assembly 22 and operates to effect angular rotational translation of the workpiece dur ing the transfer operation as described in greater detail below.

Actuating assembly 20 also includes an elongated center arm extension drive shaft member 88 extend ing coaxially through tube 56, gear 102 the associ ated bearing support 104 and outwardly Through both the top of arm assembly 20 and bottom of the bearing support 104. Suitable bushing means are provided within tube 56 to allow relatively free vertical movement of shaft 88 with respect thereto.

As previously mentioned, the lower end of drive shaft 88 has an annular groove 86 provided thereon which is defined by a pair of spaced generally radially outwardly extending flange portions 134, 136. The upper end 138 of drive shaft 88 is generally square in cross section and has provided on two adjacent side surfaces 140. 142 thereof a plurality of rack teeth.

Arm assembly 22 includes a supporting platform 144 secured to a flange portion provided on the upper end of tube 56 from which a pair of arms generally indicated by reference numbers 146 and 148 are supported in cantilevered relationship and extend generally radially outwardly with respect to the axis of tube 56 and at substantially right angles to each other.

Arm 146 includes a pair of elongated supporting rods 150,152 positioned in substantially parallel spaced relationship, each being supported by a pair of axially spaced ball bushings 164,156,158,160 mounted at opposite sides of supporting platform 144. A generally T-shaped support member 162 extends between and is secured to one end of each of the rods 150, 152 and includes a depending center section 164 having a relatively large diameter opening 166 therethrough.A generally cylindrically shaped flanged member 168 is rotatably supported within opening by means of suitable bearings 170, 172 and includes a pair of axially spaced radially outwardly extending flange portions 174, 176. A pair of support flanges 178,180 are secured to and project outwardly from the outer surface 182 of flange member 176 and are designed to have a pair of elongated support arms 184,186 secured thereto.

A suitable air actuated gripperjawassembly 188 is supportingly secured between the outer ends of support arms 184,186 with the jaw members 190 extending outwardly therefrom. As shown by a comparison of Figures 3 and 6, the actual maximum reach of arms 146 and 148 into the adjacent operating machine may be easily varied by altering the length of support arms 184, 186. Thus, relatively long arms 184', 186' such as shown in Figure 3 may be used for relatively small parts whereas larger parts requiring a short reach may be accommodated by the use of relatively shorter arms 184,186 as shown in Figure 6.Preferably in order to provide high speed response time for actuation of jaw assembly 188, a suitable solenoid operated air valve orthe like may be secured to member 162 with a high pressure air line being connected thereto. As best seen with reference to Figure 6, an air valve may be secured to the upper surface of member 162 with outlets connected to a pair of actuating air passages 1 as, 191 provided extending downwardly through support members 162 and opening into respective annular grooves 193, 195 provided within opening 166. Respective passages 197 and 201 which communicate with respective ones of annular grooves 193 and 195 are provided in flanged member 168 extending outwardly through flange 176. Suitable flexible hoses 203 and 205 may be provided to connect to the actuating cylinder of jaw assembly 188. As shown jaw assembly utilizes a double action actuating cylinder, however, in some situations a single action cylinder may be desired in which case only a single passage will be required. By mounting the valve in close proximity to the operating jaw assembly, it is possible to significantly reduce the response time operation of the jaw assembly as compared to a more remote location thereof. This is particularly important in high speed operation for which the present invention is particularly well suited.

An elongated rack 192 is also provided being positioned between supporting rods 150, 152 and extending generally parallel thereto with one end of rack 192 being secured to support member 162 between supporting rods 150 and 152. A pair of gears 194 and 196 are secured together and rotatably supported by suitable bearing means 198,200 in coaxial side by side relationship on platform 144.

Gear 196 is preferably about twice the diameter of gear 194 and is positioned in overlying meshing engagement with rack 192. Gear 194 is positioned so as to engage the rack teeth provided on side 140 of the upper end 138 of shaft 88. Thus, vertical movement of shaft 88 will operate to rotatably drive gear 194 which in turn will effect horizontal movement of arm 146 via the meshing engagement between gear 196 and rack 192. Because of the 2:1 gear ratio of gear 196 to gear 194, rack 192 will be moved twice the distance of shaft 88. In order to guide vertical movement of rod 88 suitable guide blocks 202 are provided engaging each of the four sides of end 138 of shaft 88 it being appreciated that the rack teeth provided on sides 140 and 142 extend only partially across these sidewalls.Also, in order to maintain rack 192 in proper operating position a pair of rollers 204, 206 are positioned on either side thereof. Similarly another roller (not shown) is positioned below racks 192 to provide support thereto.

Arm 148 is also positioned on support platform 144 in substantially identical manner and therefore corresponding components and portions thereof have been indicated by like numbers primed. In order to avoid interference between the racks 192 and 192' and elongated support rods 150, 152 and 150', 152', rods 150', 152' rack 192' and associated gears 194', 196' associated with arm 148 are supported at a sufficiently higher elevation to afford overlapping clearance therebetween. In this case the depending portion 164' of the T-shaped supporting member 162' will be made slightly longer so as to position the respective gripping jaws 190' at substantially the same elevation as jaws 190.

As previously mentioned, manipulator 10 also includes means to effect rotary translation of a workpiece during the transfer operation. in order to accomplish this rotational movement, a flange member 208 is provided which is supportingly secured to an elongated shaft 210. Shaft 210 is telescopically received within a second shaft 212 rotatably supported from the underside of platform 144 by suitable bearing means 214. Bevel gear 132 is drivingly connected to the inner end of shaft 212 and is operative to rotatably drive same in response to rotational indexing of platform 144. Flange 208 is in turn secured to flange 174 by a plurality of suitable threaded fasteners 216 or the like so as to thereby effect rotation of member 168 and gripping jaws 190 associated therewith.Thus, as platform 144 is rotated by shaft 56 stationary bevel gear 130 will operate to rotatably drive bevel gear 132 and hence gripping jaws 190. The degree of rotation may be easily controlled by proper selection of the gear ratio between bevel gears 130 and 132. For example, in a preferred embodiment, it is desired to be able to rotate a part through 180". Accordingly, by selecting gear 132 with a diameter equal to 1/2 that of gear 130, 180" of rotation of gripping jaws 190 will be effected during the 90" indexing of platform 144.

Typically only one of the two arms 146, 148 will be adapted to enable rotational translation of the part during the index operation although if desired both may be so designed. Additionally, in some cases it may not be desired to effect any rotation of the part.

The manipulator 10 is designed to be easily and readily adaptable to this mode of operation as well.

As shown in Figure 7, in order to prevent rotation it is first necessary to disconnect flange 208 from flange 174 by removing fasteners 216. In order to lock the gripping jaws 190 against rotational movement, portion 164 is provided with an ear 218 on the periphery thereof having an opening 220 extending therethrough. Another opening 222 extending through flange 174 is alignable with opening 220 so as to enable a suitable pin 224 to be inserted therethrough thereby preventing any rotational movement of jaws 190.

Referring now to Figures 8 through 10, the operational sequence of manipulator 10 will be described in detail with reference to transfer of a workpiece from one forming press to an associated idle station and a workpiece from the idle station to a subsequent press. In the preferred arrangement, the total cycle time including both full cycle operation of the press and of manipulator 10 will occur within three seconds, the press cycle requiring 1.5 seconds and the transfer operation overlapping sightly on the press cycle time and requiring a total of 1.875 seconds. Thus, barrel cam 26 will be rotationally driven at a speed of 32 R.P.M. or 1920/second.

As shown in Figure 9, the press begins it cycle at time T=O during which time manipulator will be positioned with one arm 148 positioned adjacent the upstream press in a retracted position and platform 144 in a lowered position as shown in Figures 2 and 4. At time T=1.125 seconds press 12 will be approximately 75% through its operation cycle and hence approximately halfway open. At this time motor 30 will be drivingly connected to and begin rotation of barrel cam 26 via actuation of clutch/brake gear reducer 28. As barrel cam 26 begins to rotate, cam follower 64 will be moved axially inwardly from end 60 of barrel cam 26 thereby effecting rotation of torque tube 58 via crank arm 62 which in turn will effect rotation of crank arms 66 and 68. Crank arms 66 and 68 will thus operate to rotate crank arm 74 supported or torque tube 76 via the engagement of roller 70 within slot 72. Rotational movement of torque tube 76 will in turn cause crank arms 78 and 80 to lower shaft 88 due to the engagement of rollers 82 and 84 in annular groove 86 at the lower end thereof. This downward movement of shaft 88 will in turn effect rotational movement of gears 194 and 194' via the meshing engagement therewith whereby gears 196 and 196' will operate to drive respective racks 192 and 192' outwardly thereby extending respective arms 146 and 148. It should be noted that is a preferred embodiment gears 194 and 196 will have a 2:1 ratio whereby the respective arms will be extended a distance equal to twice the vertical movement of shaft 88.

As shown in Figure 10, this arm extension movement of manipulator is accomplished during the initial 40" of rotation of barrel cam 26. During this period of rotation, there will be no movement of either cam followers 44 and 96. A somewhat diagrammatical representation of this arm extension sequence is shown in Figures 8a and 8b.

A time period equal to 150 of rotation of barrel cam 26 is then provided during which the gripping jaws are actuated to clamp the workpiece therebetween.

For purposes of description we shall assume that we have one workpiece positioned in the press which has just undergone a forming operation and another workpiece positioned in the idle station awaiting transfer to a subsequent forming press. Thus, both arms 146 and 148 will be simultaneously grasping workpieces.

After 55" of rotation of barrel cam 26, cam follower 44 will be moved along groove 32 in a direction toward gear reducer 28 thereby effecting rotation of torque 38 and associated crank arms 46 and 48.

Crank arms 46 and 48 will thereby operate to move tube 56 and associated collar member 112 vertically upwardly thereby lifting the entire arm assembly 22.

As noted in the graph of Figure 10, this lifting operation will require 260 of cam rotation. During the initial 160 of cam rotation of this lift cycle, arm 148 which is grasping the workpiece located in the forming press are already fully extended in order to grasp the workpiece. Thus, in order to prevent overdriving of arms 146 and 148, shaft 88 must be moved in synchronization with the movement of tube 56 and platform 144. Accordingly cam groove 34 will be contoured to impart a slight upward movement to shaft 88 identical to and synchronized with the vertical movement of arm assembly 22. This is represented diagrammatically by the change of positions of the members between Figures 8b and 8c.

At 71" of rotation of barrel cam 26, cam follower 64 will begin to be moved toward end 60 of barrel cam by groove 34 thereby commencing a retraction of the arms 146 and 148. At 800 the lift cycle will have been completed and the arms will continue to be withdrawn with complete withdrawal being reached after 111" of rotation of barrel cam 26.

At 81 " of rotation of barrel cam and when arms 146 and 148 will be sufficiently retracted to avoid interference between workpieces being moved into and out of the same press, the indexing cycle will begin. Additionally, it is also desirable to have the arms in at least a partially retracted position during indexing in order to reduce the moment arm and hence the loading and associated power requirements for accomplishing the indexing operation.

In indexing manipulator 10, cam grooves 36 will effect movement of cam follower 96 toward end 60 of barrel cam thereby effecting a counterclockwise movement of gear segment 90 which in turn will effect rotation of gear 102. Gear 102 will in turn rotatably drive tube 56 and arm assembly 22 via members 106. As previously noted, gear segment 90 has a ratio of 2:1 with respect of gear 102 and hence movement of gear segment 90 through 45" will effect a full 90" indexing of manipulator 10.

While the indexing operation is not completed until 170" of rotation of barrel cam 26, cam grooves 34 will begin to extend the arms at 145" of rotation of barrel cam 26 of completing this cycle once barrel cam 26 has rotated through 185". Also, cam groove 32 though the previously described operation will begin to lower arm assembly 22 at 175" of rotation of barrel cam with this operation being completed at 201"of rotation of barrel cam 26.

It should be noted that while the arm extension has been completed at 185" of rotation of barrel cam, the lowering motion imposed on arm assembly 22 by cam groove 32 must also be superimposed on cam groove 34 so as to enable rod 88 to lower in synchronization with arm assembly 22 thereby preventing retraction of the arm extension means during rotation of barrel cam 26 from 185" to 201".

Additionally, as previously noted, manipulator 10 is fully reversible without need to alter or change barrel cam 26 but merely be reversing the direction or rotation thereof. Accordingly, this motion superimposed on cam groove 34 will operate to maintain arms 146 and 148 in a fully extended position during raising of arm assembly 22 when barrel cam 26 is rotated in the opposite direction.

Arms 146 and 148 are now in a fully extended position with arm assembly 22 fully indexed through 900 and in a lowered position. Hence, the workpiece previously located in the press has been moved to the idle station whereas the workpiece located in the idle station has now been transferred and placed into the next adjacent forming press. A dwell period of 15" (from 201" to 216" rotation of barrel cam 26) is provided to enable time for gripping jaws 190 to release the workpiece.

Once the workpiece has been released arms 146 and 148 will be retracted with full retraction being completed after 2560 of rotation of barrel cam 26. At this point a dwell period of 100 of rotation of barrel cam 26 is provided in the contour of cam grooves 32, 34 and 36 before manipulator 10 is indexed back to the initial position by cam groove 36 with the return indexing being completed at 3500 of rotation of barrel cam 26. Thus a second dwell period of 10" of rotation of barrel cam 26 is also provided at the end of the cycle. This second period of dwell is provided to enable clutch/brake gear reducer 28 to operate to disengage motor 30 from driving barrel cam 26 and to brake barrel cam 26 to a stop. The first 100 dwell period /that period between 2560 and 2660 of rotation of barrel cam 26) is provided for the same purpose but is utilized when barrel cam 26 and manipulator 10 are being operated in the opposite direction. This reverse operation will be identical in timing and sequence as shown by the graph of Figure 10 but with the starting point of 0" being at 256" and the cycles proceeding to the left as shown therein, it being noted that the labeled operations shown there will be reversed because of the reverse direction of rotation of barre cam 26.As thus described manipulator 10 is able to complete a full operational cycle comprising extending of arms, grasping a workpiece, lifting the workpiece, retracting the arms, indexing through 90", extending the arms and lowering same all within a single revolution of barrel cam 26. In preferred embodiment, this full cycle of operation is completed within 1.875 seconds and by overlapping a portion of this operation with the press opening cycle is able to offer a production rate of 1200 pieces per hour or one part processed every 3 seconds. Preferably each of the manipulators will be substantially identical thereby offering the advantages of easy maintenance and requiring fewer numbers of spare parts to be maintained by the user.

The ability to arrange the manipulators in alternating relationship with a row of operation performing machines and thereafter supply workpieces from either or both ends simultaneously depending upon the number of operations required for manufacturing the desired parts offers great flexibility with a minimum amount of changeover time and effort.

Thus, the productivity of the manufacturing equipment is substantially increased.

It should be noted that while as described manipulator 10 is designed to provide high speed transfer of parts between adjacent forming presses or the like located in side by side relationship, other arrangements are equally possible. For example, were a pair of operation performing machines to be positioned at right angles to each other, a manipulator in accordance with the present invention having only a single arm could be utilized to effect transfer directly from one machine to the next. Another possible alternative would be to position arms 146 and 148 to extend outwardly 180" and to provide 180" indexing with full 360" rotation of the arms being accomplished every 2 cycles thereby eliminating the need for an idle station. However, this would require sufficient clearance on the backside of the adjacent operating machinery to accommodate movement of the arms.Further, manipulator 10 should not be viewed as limited to transfer of workpieces between adjacent operation performing means as it may also be used to transfer workpieces from other transfer equipment (i.e. conveyor line) to one or more operation performing and thereafter return the workpiece to the same or other transfer equipment. Thus, the potential applications for manipulator 10 are very numerous and well accommodated by the flexibility provided in the design thereof.

Referring now to Figures 11-13, there is shown an alternative embodiment of a manipulator in accordance with the present invention, being generally indicated by reference number 250. Manipulator 250 is very similar in both structural arrangement and cycle and functional operation to that of manipulator 10 and accordingly corresponding portions thereof have been indicated by like numbers primed.

Manipulator 250 utilizes three separate barrel cams 252,254, and 256 in lieu of a single barrel cam 26 each of which are secured to and driven by a common shaft 258.

Cam 252 is operative to extend/retract respective arms 146' and 148' by means of cam groove provided on the surface thereof. Cam follower 260 includes a scotch yoke type driving connection with crank arm 262 being defined by groove 264 which receives follower pin 266 secured to the end of crank arm 262. Crank arm 262 operates to drive a second crank arm 268 via torque tube 270, crank arm 268 being in turn connected to the lower end of rod 88'.

Both crank arms 262 and 268 and associated torque tube 270 are supported from and vertically movable with a main housing 272. Because of the scotch yoke drive connection between cam 252 and crank arms 262, vertical movement of housing 272 will not alter the arm extension/retraction position and thus there is no need to superimpose the vertical movement of the arms on the cam groove contour of cam 252.

Cam 256 is operative to provide the desired vertical movement by means of a cam follower 274 secured to the end of crank arm 276. The other end of crank arm 276 drivingly engages an annular groove 278 provided on main housing 272 so as to effect vertical movement thereof.

Cam 254 is operative to impart the indexing movement via cam follower 280 provided on large diameter gear 282. Gear 282 is positioned in vertical sliding engagement with a smaller diameter gear 184 provided on the lower portion of housing 272.

Thus, vertical movement imparted by cam 256 will be accomplished along with relative axial movement of gears 282 and 284.

An arm assembly 22' is supported on the upper end of main housing 272 and includes a similar rack and pinion drive arrangement for effecting extension and retraction of arms 146' and 148', corresponding portions thereof being indicated by like numbers double primed. However, in place of guide rods 150, 152 a single guide bar 286 is provided along which a slider support 288 is mounted. Rotatably supported from slider support 288 is a shaft 290 which telescopically receives one end of a drive rod 292. Suitable gripper jaw means 190' are secured to the other end of shaft 290.Drive rod is operative to rotatably drive shaft 290 and has a bevel gear 294 secured to the inner end thereof which meshingly engages a second bevel gear 296 non-rotatably supported on the upper end of housing 272 in substantially coaxial relationship to and surrounding the upper end of rod 88'.

As previously mentioned, manipulator 250 is fully operative each of the desired sequences of operation in substantially the same manner and offers many of the same advantages as described above with respectto manipulator 10. It should be noted, however, that while there may be applications where the design of manipulator 250 is preferred it is believed the elimination of the scotch yoke connection in the cam drive and the arm support arrangement of manipulator 10 are generally preferred. It should be noted, however, that while three separate barrel cams have been shown in the embodiment of Figures 11-13, it would be possible to combine these to a single barrel cam as described with reference to manipulator 10 if desired.

Claims (22)

1. AmulU-a > s manipulator for effecting high speed transfer of workpieces into and out of operation performing means, said manipulator comprising: drive means; first and second arm means angularly positioned with respect to each other, each of said arm means including gripping means for grasping a workpiece; first means driven by said drive means for moving said first and second arm means along a first axis; second means driven by said drive means for moving said first and second arm means along a second axis; indexing means driven by said drive means for revolving said first and second arm means about one of said first and second axis; and each of said first and second moving means, and said indexing means being independently driven by said drive means.

2. A multi-axis manipulator as set forth in claim 1 wherein said drive means comprise a single barrel cam having a plurality of cam grooves provided thereon.

3. A multi-axis manipulator as set forth in claim 1 further comprising means for effecting rotational movement of one of said first and second arm means in response to said revolving movement of said arms.

4. A multi-axis manipulator as set forth in claim 3 wherein said means for effecting rotational move ment of said one arm includes a driving member selectively removable connectable to said gripping means and said arm means includes locking means for cooperating with said gripping means to selectively prevent relative rotation of said gripping means during said revolving movement of said arms.

5. A multi-axis manipulator for effecting high speed transfer of workpieces into and out of operation performing means, said manipulator com prising: an arm assembly; a driving motor; a barrel cam drivenly connected to said motor, said barrel cam having a plurality of endless cam grooves provided on said barrel cam; a first cam follower engaging one of said cam grooves and operatively connected to said arm assembly to move said arm assembly along a first axis; a second cam follower engaging another of said cam grooves and operatively connected to said arm assembly to move portions thereof along a second axis;; said second cam groove having a contour super imposing part of the movement created by the engagement of said one cam groove and said first cam follower on the movement of said portions of said arm assembly resulting from the engagement of said second cam follower with said another of said cam grooves whereby said part of the move ment of said arm assembly along said first axis may be accomplished without affecting movement of said portions of said arm assembly along said second axis.

6. A multi-axis manipulator for effecting high speed transfer of workpieces into and out of opera tion performing means, said manipulator com prising: a supporting base; an arm assembly including a platform; first and second arm members angularly positioned with respect to each other and movably supported on said platform, each of said arm members including drive means supported on said platform for linearly reciprocating said arm members; means provided on the outer ends of each of said arm members for gripping a workpiece; an actuating assembly including a hollow cylindrical elongated tube member, said arm assemby being secured to one end thereof; means movably supporting said tube member of said base;; gear means rotatably supported on said base coaxially with said tube member and including means rotatably drivingly connecting said gear means to said tube member; an elongated rod member extending movably coaxially through and outwardly from opposite ends of said tube member and through said platform, the end of said rod extending through said platform being drivingly engageable with each of said arm member drive means; and a drive assembly including motor means supported on said base; cam means rotatably supported on said base and drivenly connected to said motor means said cam means including a plurality of cam grooves; a gear segment rotatably supported on said base and adapted to be rotatably driven by the engagement of a first cam follower secured to a portion thereof engaging one of said plurality of cam grooves, said gear segment being positioned in meshing driving engagement with said gear means whereby said one cam groove is operative to rotatably drive said tube member whereby said arm members may be indexed between first and second positions;; second cam follower means engaging another of said cam grooves and being drivingly connected to said rod member and operative to axially reciprocate said rod member whereby said rod member may operate to linearly reciprocate each of said arm members; and third cam follower means engaging a third one of said cam grooves and being drivingly connected to said tube member, said third cam follower being operative to axially reciprocate said tube member and said platform supported thereon whereby said arm members are reciprocate in a direction parallel to the axis of rotation of said tube member.

7. A multi-axis manipulator as set forth in claim 6 wherein said another of said cam grooves is contoured so as to superimpose at least a portion of the axially reciprocating movement of said platform resulting from the engagement between said third cam follower and said third one of said cam grooves.

8. A multi-axis manipulator as set forth in claim 6 wherein each of said plurality of cam grooves are continuous and are operative to drive respective of said first, second and third cam followers through an operational cycle for each revolution of said cam means.

9. A multi-axis manipulator as set forth in claim 6 wherein said cam means comprise a single barrel cam having a plurality of cam grooves provided thereon.

10. A multi-axis manipulator as set forth in claim 6 wherein said cam means and said first, second and third cam follower means cooperate to drive each of said arms through an operational cycle during which said arms are linearly extended, axially extended, linearly retracted, rotatably indexed in one direction, linearly extended, axially retracted, linearly retracted, and then rotatably indexed in the opposite direction, each of steps being initiated sequentially.

11. A multi-axis manipulator as set forth in claim 10 wherein said cam means may be rotated in either direction without altering the sequence of initiation of said steps.

12. A multi-axis manipulator as set forth in claim 6 wherein said arm assembly includes means for rotating said gripping means in response to revolving movement of said arms about the axis of said tube.

13. A multi-axis manipulator as set forth in claim 12 wherein said rotating means comprise a first bevel gear secured to said means for supporting said tube and a second bevel gear in meshing engage menttherewith, said gripping means being rotatably supported on said arm and said second bevel gear being drivingly connected thereto.

14. A multi-axis manipulator as set forth in claim 13 further comprising selectively connectable clutch means interconnecting said second bevel gear and said gripping means.

15. A multi-axis manipulator as set forth in claim 14 wherein said clutch means comprise a first flange secured to said rotatable gripping means and a second flange drivenly connected to said second bevel gear, removable fastener means for joining said first and second flange means in driving relationship and locking means provided on means for rotatably supporting said gripping means and cooperable with said first flange whereby rotation of said first flange may be prevented when said second flange is disconnected therefrom.

16. A multi-axis manipulator as set forth in claim 15 wherein said second bevel gear is secured to one end of a hollow rotatable shaft and said second flange is secured to one end of another shaft said another shaft being telescopically received within said hollow shaft and non rotatable with respect thereto.

17. A multi-axis manipulator for effecting high speed transfer of workpieces into and out of operation performing means, said manipulator comprising: drive means; arm means including gripping means for grasping a workpiece; first means driven by said drive means for reciprocatingly moving said arm means along a first axis; second means driven by said drive means for reciprocatingly moving portions of said arm means along a second axis; indexing means driven by said drive means for revolving said arm means about one of said first and second axis;and selectively connectable means for effecting rotational movement of said arm means in response to revolving movement of said arm means; each of said first and second moving means, and said indexing means being independently driven by said drive means.

18. A multi-axis manipulator as set forth in claim 17 wherein said drive means comprise a driving motor; a barrel cam drivenly connected to said motor, said barrel cam having a plurality of endless cam grooves provided on said barrel cam; said first means include a first cam follower engaging one of said cam grooves and operatively connected to said arm assembly to move said arm assembly along a first axis; said second means include a second cam follower engaging another of said cam grooves and operatively connected to said arm assembly to move portions thereof along a second axis;; said second cam groove having a contour superimposing part of the movement created by the engagement of said one cam groove and said first cam follower on the movement of said portions of said arm assembly resulting from the engagement of said second cam follower with said another of said cam grooves whereby said part of the movement of said arm assembly along said first axis may be accomplished without effecting movement of said portions of said arm assembly along said second axis.

19. A multi-axis manipulator as set forth in claim 17 wherein said arm means comprise a platform; first and second arm members angularly positioned with respect to each other and movably supported on said platform, each of said arm members including drive means supported on said platform for linearly reciprocating said arm members, said second means being operative to drive said linear drive means.

20. A multi-axis manipulator for effecting high speed transfer of workpieces into and out of operation performing means, said manipulator comprising: a supporting base; an arm assembly including a platform; an arm member movable supported on said platform, said arm member including arm drive means supported on said platform for linearly reciprocating said arm member; means provided on the outer ends of said arm member for gripping a workpiece; an actuating assembly including an elongated member movably supported on said base, said arm assembly being secured to one end thereof; means for rotatably indexing said elongated member and said arm assembly; means for axially reciprocating said elongated member and said arm assembly independently of said rotatably indexing means; a rod member operatively drivingly connected to said arm drive means; and cam drive means including a first cam means and associated follower for actuating said rotatable indexing means, a second cam means and associated follower means for actuating said axially reciprocating means and a third cam means for actuating said rod member whereby said manipulator may operate to transfer a workpiece from a first location to a second location.

21. A multi-axis manipulator as set forth in claim 20 wherein said cam drive means is operative to cycle said arm member through a linear movement in a first linear direction, an axial movement in a first axial direction, a linear movement in the opposite linear direction, a revolving movement in a first rotating direction resulting from said rotatable indexing a linear movement in said first direction, an axial movement in the opposite direction, a linear movement in said opposite direction and a revolving movement in the opposite rotating direction each of said cycles being sequentially initiated.

22. A multi-axis manipulator constructed and arranged to operate substantially as herebefore described with reference to and as illustrated in the accompanying drawings.