CA1050577A - Material handling apparatus - Google Patents

Abstract

MATERIAL HANDLING APPARATUS
ABSTRACT
Several embodiments of a material handling apparatus adapted to grip a workpiece and move it from one position to another position where it is released. Each apparatus includes gripping means that is moved between a released position and a gripping position and a carrier for the gripping means that is movable from a first position to a second position. Actuating means moves the gripping means to its gripping position when the positioning means move the carrier to a first position and for moving the gripping fingers to a released position when the positioning means moves the carrier to its second position. In two embodiments of the invention the apparatus includes a pair of motion transfer means, each of which is adapted to move the gripping means in a respective direction between first and second extreme positions. A timing mechanism is included that operates the motion transfer means so as to move the workpiece from a home position to a work position. The mechanism also includes means for automatically moving the gripping means between its gripping position and its released position when the workpiece is so transferred. By the addition of certain elements the path of movement of the gripping means may be altered and by a relatively simple adjustment the sequence of operation may be reversed. In one embodiment of the invention one direction of movement accomplished by one of the motion transfer means is pivotal.

Description

105S)5 ~7 BACKGROUND OF THE INVENTION

This invention relates to a material handling apparatus and more . .
particularly to a simplified, improved material handling apparatus for positioning workpieces or the like.
In many machine operations or other automated operations it is desirable to provide a mechanism that can move a workpiece between two different positions.
Such material handling apparatus should be designed so as to permit a lattitude in the sequence of movement, to insure against damage to the workpiece and aYsociated mechanism in the event of jamming and should be relatively low in cost.

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It is, therefore9 iq principal object of this invention to provide an improved low cost material handling apparatus.
It is another object oE the invention to provide a material handling appara~us that i5 adapted to move workpieces between two different positions and accomplishes this result by a relatively low.cost mechanism.
It is a further vbj.ect of the invention to provide a mate~ial handling apparatus that permits a wide lattitude in .~ degrees of movement and in sequence of operation.
10 SU~MARY OP THE INVENTION
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In its broadest form the present invention provides a material handling apparatus for moving workpieces or the like between a first location and a second location, gripping means, supporting means supporting the gripping means for movement ~
between a gripping position in which a workpiece is gripped and a released position, the supporting means being movable to pssition i -: , , ~he gripping means in the first location and in a second location, ~ .
s~ngle drive means including an element movable between a first ~ position and a second position, means including a lost motion -, 20 connection operab.ly connecting the drive means element to the i supporting means for moving the gripping means between the first ` locatio~ and the second location in response to movement of the ~, drive means element, the lost motion connection being effective to permit movement of the drive means element from a position -intermediate its first position and its second position to its first position when the gripping means remains in its first loca-tion, actuating means responsive to the movement of the drive means element from ita intermediate position to it.s first position ~. relative to the gripping means $or moving the gripping means from ,, .~, . .

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5~'7 one of its positions to the other of its p~sitions, locking ~ean8 for retaining the gripping means in its other position upon move-ment of the gripping means from its first location to its second location, and means responsive to the movement of the gripping ~eans to its second location for releaslng the locking means and permitting the actuating means to move the gripping ~eans from itg other position to its one position.
Another embodiment of this invention derived from the one describe~ above is also adapted to be embodied in a material handling apparatus that includes the gripping mean~ ~or releasably restraining a workpiece and the support means for the grippi~g means. A first motion transfer means is incorporated for moving the support means for movement in a first direction betwePn a irst extreme position and a seco=d extreme position. A second motion t~ansfer means is provided for moving the support means in a second direction between a first extreme position and a second extreme position. The second direction is angularly related to the first , ~` direction. Timing means operate the! motion transfer means so that the supporting means is moved to se!quence by the respective moti~n transfer means from a home position to a wo~ position.
In accordance with a third embodiment of this inventio~, a material handllng apparatus as described in the preceding parrgraph is provided. In such , ', ~ ', , ;

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an embodiment the direction of movement provided by one of the motion transfer means i9 pivotal.
BRIEF DESCR~PTION OF THE DRAWINGS
Figure 1 i~ a ~ide elevational view, with portions broken away, of a material handling apparatus incorporating a ffrst embodiment of this invention and ~hows the apparatus in a retracted, open position.
Figure 2 i9 a cross sectional view of the apparatus shown in Figure 1 taken along the line 2-2.
Figure 3 is a side elevational view, with a portion broken away, in part similar to Figure 1, and shows the apparatus in its extended, gripping position.
Figure 4 is a cross sectional view taken along the line 4-4 of Figure 3.
Figure 5 is an end view of the apparatus taken generally in the direction of the arrow 5 in Figure 1.
Figure 6 is an end view taken in the direction of the arrow 6 in Figure 1, with a portion broken away.
Figure 7 i9 a perspective view of a material handling apparatus in accordance with a second embodiment of this invention.
~: Figure 8 is a side elevational view of the gripping device of the embbdiment shown in Figure 7.
Figure ~ i~ a top plan view of the gripping device of this embodiment.
Figure 10 is an enlarged, cro~s sectional view taken on a vertical plane through the embodiment of Figure 7.
Figure 11 is a cross sectional view taken along the line 11-11 of Figure 'I 10.
Figure 12 is a perspective view of a material handling apparatus in accordance with a third embodiment of this invention.
Figure 13 ia an enlarged ~ide elevational view of the gripping device of the embodiment ehown in Figure 12.
Figure 14 ia a top plan view of the gripping device of Figure 13.

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Figure 15 is an enlarged, croas ~ectional view taken on a vertical plane through the embodiment shown in Figure 12.
Figure 16 is a cross sectional ~iew taken along the line lB-l~ of Figure 15.
DETAILED DESC~IPTION ~F THE PREFERRED EMBODIMENTS

The reference numeral lt indicates generally a material handling apparatus in accordance with a first embodiment of this invention. The material handling apparatus 11 includes a base plate 12 that is adapted to be affixed in any known manner to an associated component of a machine tool or the like. ~ cylinder assembly 13 i~
supported upon a base plate 12. In this embodiment, the cylinder assembly 13 i8 su~pported for pivotal movement since the material handling apparatus i8 adapted to move a workpiece in two directions. As will become apparent, the cylinder assembly 13 may be rigidly mounted upon the base plate 12 in the event movement in only one direction is required.
; A pair of spaced trunions 14 are fixed to the base plate 12 on opposite sides of the cylinder 13. The trunions 14 receive pivot pins 15 that are affixed by machine screws 16 to the cylinder 13 to pivotally suppo:rt the cylinder 13 on the base plate 12. A bell crank 17 is pivotally connected to one side of the cylinder 13 by means of a pivot pin 18 and machine screw 19. The bell crank 17 carries a roller 21 at one of its ends on a shaft 22. The roller 21 bears against a washer or bearing plate 23 that is adjustably fixed to the base plate 12 by means of a machine screw 24, nut 25 and jam nut 28.
The cylinder 13 is ~ormed with a longitudinally extending bore 27 (Fig-ure 2) with counterbores 28 and 29 formed at its opposite ends. Plain bearings 31 and 32 are received within thc counterbores 28 and 29 and held in place by respective snap rings 33 and 34. The bearings 31 and 32 slidably support a positioning member, indicated generally by the reference numeral 34. The positioning member 34 carrie~
a gripping mechanism, indicated generally by the reference numeral 35, at it~ outer end.

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The gripping mechanism includes a pair of gripping fingers 36 and 37 that are positioned in a cavity 38 formed at a bifurcated end of a supporting collar 3~.
The supporting collar 39 i9 affixed in any suitable manner to the outer end of the po~
tioning member 34. The gripping fingers 36 and 37 are pivotally supported for move-ment between an opened position and a gripping position by means of respective pivot pins 41 and 42. A coil compression spring 43 is positioned between the outer ends of the gripping fingers 36 and 37 to urge the fingers to the opened position as shown in Figure 2. The gripping fingers 36 and 37 are adapted to carry any suitably configured jaws (not shown) for engaging a workpiece.
The positioning member 34 has a generally tubular shape and has a longitudinally extending bore 44. Counterbores 45 and 46 are formed at the opposite ends of the bore 44 and receive respective plain bearings 47 and 48. The bearings 47 and 48 are held axially in position by respective snap rings 49 and 51. An actuating member 52 for the gripping fingers 36 and 37 is slidably supported by the bearings 47 and 48. The actuating member 52 has an extending cam portion 53 that engages the inner ends of the gripping fingers 3B and 37.
A detent member 55 (Figures 1 and 3) i8 sli~ably supported in a bore 5B
of the collar 39 which intersects a bore 57 through which the actuating member cam portion 53 extends. The detent member 55 has a cylindrical end portion 58 that is adapted to cooperate with a cylindrical groove 5~ ~ormed in the actuating member 52 for retainirlg the actuating member in a position in uvhich the gripping fingers 38 and 37 are held in their gripping po5ition (Figures 3 and 4) .
The detent member 55 is formed with a conical recess 61 that is adapted to receive a complimentary shaped conical plunger 62. The plunger 62 is slidably supported in a bore 63 formed adjacent and parallel to the bore 57. The plunger B2 is encircled by a coil compression spring 64 that engages a ~houlder 65 formed adjacent the pluneer conical portion û2. The opposite end of the spring 64 engages a shoulder 66 formed on the plunger to urge the plunger to the position shown in Figure 3. In this position, the detent member 55 may engage the circumferential , ., : .
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~S~i7 groove 59 of the actuating member 52.
A pneumatic or hydraulic actuating cylinder, indicated generally by the reference numeral 67 is supported on the cylinder 13 in any known manner, by means of machine screws 68. The actuating cylinder 67 includes a piston rod 69 that will reciprocate upon operation of the cylinder 67 between a first position as shown in Figures 1 and 2 and a second position as shown in Figures 3 and 4. A plate 71 is fixed to the outer end of the piston rod 69 by means including a threaded end 72 of the piston rod and nut 73. The plate extends from the piston rod 69 to the actuating member 52 and is also affixed to the actuating member 59 by means of a threaded end 74 of the latter and a nut 75 (Figure Z) . Thus, reciprocation of the piston rod 69 will be transmitted into reciprocation ~f the actuating member 52.
A plurality of compression springs 76 are received in complimentary bores 77 of the plate 71. The opposite ends of the springs 76 are received in bores 78 of a collar 79 that is affixed to the end of the positioning member 34. The springs 76 tend to maintain the plate 71 and collar 79 in a spacecl relationship as shown in Figures 1 and 2.
The plate 71 also has affixed to it a pin member 81 that has a reduced diameter portion which is slidably received in an elongated slot 82 of an actuating link 83. The actuating link 83 is pivotally connected to the bell crank 17 by means of a pivot pin 84. The construction consisting of the pin 81, actuating link 83 and pivot pin 84 is provided when translational movement of the cylinder 13 i3 desired, as will become apparent.
Aa has been noted, the material handling apparatus 11 may be used for a variety of purposes. For example, the material handling apparatua 11 may be used to remove workpieces from a press thus obviating the necessity for an operator to place his hands in the dangerous portion of the press.
Figurea 1 and 2 illustrate the device in a retracted position in which the gripping fingers 33 and 37 are opened. In this position, the piston rod ~9 of the actuating cylinder 87 i~ in its extreme position. A~ a result, the poaitioning ~ ; :
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member 34 will be moved to an inward extreme position along with the gripping mechanism 35. The springs 76 will urge the positioning member 34 relative to the actuating member 52 so that the actuating member cam portion 53 will permit the gripping fingers 36 and 37 to pivot to their open position. At this time, the plunger 62 will be engaged with a face of the cylinder 13 so that the plunger conical portion fits into the conical opening 61 of the detent 55 to hold the detent 55 in a retracted position.
When it is desired to remove a workpiece from the associated press, the cylinder 67 is actuated so that the piston rod 69 begins its stroke from the position shown in Figure 1 to the position shown in Figure 3. Initial movement of the plate 71 will cause the positioning device 34 and actuating device 52 to move together, the force to the former being transmitted through the springs 7B. During this initial movement, the pin 81 will traverse the slot 82.
As the gripping device 35 moves away from the cylinder 13, the plunger 62 will be urged by the spring 6~ to the position shown in Figure 3 so that the detent 55 will be in position ~or operation. The detent 55 will not, however, engage the groove 59 at this time since the actuating mernber 52 will still be in the position shown in Figure 2. As the gripping device 35 approaches the workpiece, --the collar 7~ will engage an adjustable stop 91 threaded onto an end of the cylinder 13 and prevent the positioning member 34 from further movement. At this time, the spring 76 will compress and permit relative movement betwesn the positioning member 34 and the actuating member 52. Thus, the actuating member cam portion 53 will move between the gripping fingers 36 and 37 from the position shown in Figure 2 to the position ~hown in Figure 4 cau~ing the gripping fingers 3B and 37 and the jaws carried thereby (not shvwn) to move into gripping engagement with the workpiece.
When thi~ occur~, the detent 55 will be cammed over the enlarged portion of the actuating member 52, b~r an inclined ~urface ~2, and fall into place in the groove 5û~
The gripping ffn~er~ 30 and 37 are, there~ore, retained in their gripplng positlon while the workplece le held, : , ~, ~ - , : . .
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~lD 5~5~7 During the final movement of the piston rod 69, the pin 81 will have completed its traversal of the slot 82 and cause a force to be exerted on the actuating link 83. Thi3 force is transmitted through the pivot pin 84 to the bell crank 17. The roller 21 will engage the plate 23 and cause the forward end of the cylinder 13 to be pivoted relative to the supporting plate 12 from the position shown in Figure 1 to the position shown in Figure 3. Thus, the gripping device 35i8 mo~ed in two sense~.
If desired, this latter degree of movement may be eliminated by elimination of the link 83 and the bell crank 17 although the latter element need not be deleted.
When the workpiece has been gripped by the jaws associated with the gripping fingers 36 and 37, the actuating cylinder 67 is operated to cause reversal ~:
of the movement of the piston rod 69. The piston rod 69 will then extend carrying with it the plate 71. Since the detent 55 is received in the groove 59, the positioning member 34 and actuating member 52 will be constrained from movement together and the springs 76 will be held compressed. The elements, therefore, move together to remove the workpiece and draw it toward the cylinder 13. Thi8 movement continues until the plunger 62 engages the cylinder 13. At this time, the plunger will be driven forwardly so that its conical end portion enters the conical opening 61 of the detent 55.
Continued movement will cause the detent 55 to be withdrawn free of the groove 53 and permit relative movement between the actuating mennber 52 and positioning member 34. The compression on the springs 76 will then be released and the jaw~
3~ and 37 will be urged to their open position by the spring 43. The workpiece will then fall free of the associated gripping jaws.
EMBODIMENT OF FIGURES ~
A material handling apparatus constructed in accordance with a second embodiment of this invention is identified generally by the reference numeral 111.
The material handling apparatus, like the earlier embodiment, is adapted to be used wlth a variety of machine tool or other operations for moving workpieces between respectiva positions. Aa examples of applicationa for tl~s device, the material handling apparatu~ 111 may be used to pick worlcpiecea from a storage bin and place ,~ .
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them onto a transfer table, remove workpieces from a transfer table or machine tool nnd place them on a conveyor, or move workpieces from one location to another in an assembly operation. Various other applications for the material handling apparatuY
111 will present themselves to those skilled in the art.
The material handling apparatus 111 includes an outer housing as~embly 112 having an input drive assembly 113. The input drive as6embly 113 transfer3 drive from a suitable power source (not ~hown) via motion transfer means, to be described, to a gripper assembly, indicated generally by the reference numeral 114.
The gripper assembly 114 includes a pair of gripping jaws 115 and 11 that are pivotally supported by means of pivot pins 11i and 118 upon a supporting member 119. The jaws 115 and 11~ provide respective ways 120 that are adapted to afford a detachable and adjustable connection to a respective pair of inserts 121 and .
122. In this embodiment, the inserts 121 and 122 have facing V-shaped surfaces 123 and 124 that are adapted to grippingly engage a worl~piece. The inserts 121 and 122 are mounted for longitudinal adjustment on intermediate supporting members 125 and 12~ which are, in turn, laterally adjustable along the ways 120 of the jaws 115 and 116.
The jaws 115 and 116 have inwardly projecting lever arm portions 127 and 128 in which arcuate recesses 129 and 131 are formlsd. Pins 132 and 133 are re-ceived in the respective recesses 129 and 131. The pins 132 and 133 are, in turn, affixed to an actuating element 134 which is slidably ~upported within the supporting member 119. An operating rod 135 iB affixed to the mennber 134 for reciprocating it between an opened poaition, as shown in the solid line view of Figure 9 to a clo~ed position in which the jaw inserts 123 and 124 move to the broken line position of this Figure.
The supporting member 119 ha~ a cylindrical trunion portion 13û that i~
journaled in a complimentary surface of a aaddle 137. The saddle 137 iB integrally formed with an offset supporting arm 138. A clamping member 139 complete~ the ~upport of the supporffng member 119 and ia affixed to the satldle 137, by socket head machine screws 141. Loo6ening of the machine ~crews 141 permits rotation oi' ,, : ! _ 9 _ .1 . ~ , .. .

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the ~upporting member 119 within the saddle 137 80 that the orientation of the jaw~
115 and 116 may be adjusted relative to the remainder of the material handling apparatu~ 111.
The operating rod 135 has an extending portion 142 that i3 received within the arm 138. Oppositely facing shoulders, 143 and 14'1 are formed by enlarged cylindrical portions 145 and 146 of the operating member projection 1~2. A bifurcated jaw actuating mechanism 147 i~ received between the shoulder~ 143 and 144 and i9 pivotally supported on the arm 138 by means of a pivot pin 148.
Referring now in detail to Figures 10 and 11, the outer housing 112 defines an enlarged internal cavity 151. A pair of vertically extending supporting rods 152 and 153 are fixed to the forward end of the outer housing 112 adjacent to an opening 150 formed in the forward wall 154 of the outer housing 112. The rodY 152 and 153 are affixed in respective cylindrical openings formed in the outer housing upper and lower walls 155 and 15e. A first supporting block 157 has a pair of cylindrical bores 158 and 159 for slidably supporting the block 157 on the rods 152 and 153. The block 157 is, therefore, free to move vertically relative to the outer housing 112, and is operated along this plane of movement in a manner to be described.
The supporting arm 138 has affixed to it a pair of guide rods 161 and 182.
The guide rods 161 and 162 are slidably supported in cylindrical bores 163 and 164 of the supporting block 157. The arm 138 i~, therefore, ~lidably ~upported relative to the block 157 for movement in a plane that is perpendicularly disposed to the plane of movement of the block 157.
The inner ends of the rod~ 161 and 162 are affixed to a follower member 165. The foliower member 165 defme8 a vertically extending way 166 in which a cam member 167 i8 Blidably positioned. The cam member 167 i8 journaled on a pivot shaft 168 formed at the outer end of a bell crank 169. The bell crank lB0 is pivotally supported by the outer housing 112 by means of a supporting pivot shaft 171.
Intermediate its ends, one arm of the bell crank 160 carries a second follower roller 172. The second follower roller 172 is journaled on a supporting ~haft ' . ~~ ....... .
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..1 5i7'7 173 and engages a first cam 174 of a timing mech~nism, indicated generally by the reference numeral 175. The first cam 174 is affixed, in any known manner, to an input shaft 176 that i8 journaled by means of anti friction bearings 177 and 178 affixed in side walls 179 and 181 of the outer housing 112. The end of the shaft 176 journaled by the bearing 178 extends into a gear housing 182 affixed, in any known manner, to the housing wall lnl. The gear housing 182 forms a portion of the drive mechani~m 113. The extending end of the shaft 176 carries a worm wheel 183 that i~ enmeshed with a driving worm 184 for rotating the shaft~8~
A second block 185 has a pair of vertically extending bores 186 and 187 for slidably 6upporting this block on the support rods 152 and 153. The block 185 has affixed to it a shaft 188 that is encompassed by a bifurcated end 189 of a secon~
bell crank, indicated generally by the reference numeral 191. The bell crank 191 i9 pivotally supported on the outer housing wall i79 by means of a pivot pin 192. Inter-mediate its ends, one arm of the bell crank 191 carries a follower 193 that is engaged with a second timing cam 194 fixed to the shaft 176.
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The follower 172 of the first bell crank 189 is urged into engagement with its regpective cam 174 by means of a tension spring 195. One end of the tension spring 195 iB affixed to 8 second arm 19~ of the bell crank 189. The opposite end of the spring 195 i8 a~fixed to a pin 197 that i~ carried by the top wall 151 of the outer housing 112.
In a likc manner, the second bell crank follower 193 ij urged into en-gagement with its respective cam 194 by means of a tension spring 1~9. One end of the tension spring 198 i~ affixed to a second arm 199 of the bell crank 191. The . oppo~ite end of the ~pring 198 iB connected to a pin 201 that iB affixed to the outer housing front wall 15~.
The second block 185 has a forwardly extending projection 202 in which a horizontally disposed bore 203 i~ ~ormed. The bore 203 slidably supporte an elong~ted rod 204 to which is affixed a collar 205. The collar 205 has staked to ~t B
:- pivot pin 208. 'rhe pivot pin 20~ iB journaled in an extending arm 207 of the jaw ~:ctuatlng member ~.

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A blocking lever 208 i9 pivotally 6upported upon the block 157 by means of a pivot pin 209. The blocking lever 208 has a projection 211 that i9 adapted to engage a resilient stop 212 affixed to a lever 213. The lever 213 is journaled fs>r pivotal movement upon a shaft 214 that i~ affixed to the outer housing 112. The lever 213 has a follower portion 215 that is adapted to engage a cam 216. The cam 216 i9 : . . ,~ 1~
~'~ positioned upon the shaft 176 along with the cams 17~ and 194. The cam 2~i6 formed with a bore 217 that is adapted to receive a pin 218. The pin 218 also is adapted to extend into one of two complementary holes 219 formed in the cam 174 at spaced 180 location6. As will become apparent, which of the holes 219 the pin 218 and cam 218 are keyed to determines the sequence of gripping and release operation of the gripping jaw6 115 and 116.
A tension spring 221 is affixed to a pin 222 carried by the lever 213 for urging it6 follower portion 215 into engagement with the cam 216. The opposite end of the ten6ion spring 221 is affixed to the outer housing 112 by means of a pin 223.
A generally L-shaped blocking member 224 is affixed to the block 185.
The blocking member 208 has an extending arm portion 225 that is adapted to cooperate with the block 224, in a manner to be described. A tension 6pring 22B i~ affixed by means of a pin 227 to the blocking member 208 at one of it6 ends. The opposite end of the spring 226 i6 connected to the block 185 by means of a pin 22~. The spring 226 exerts a clock-wise bias on the pivotally supported blocking member 208.
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Figures 7~11, except for the dotted line view of Figure 9, show the material handling apparatus 111 in a home position with the gripping jaws 115 and 116 open. The apparatus 111 i6 ~et up in the described embodiment to grip a work-piece in the position shown in the figures, raise it, when viewed in accordance with Figure 10, along the Y axi6, ~ubsequently tran61ated acro~3s the X axi6 to an extreme po~ition, and sub~equently lower it retraversing it~ movement along the Y axi0 where the piece i~ deposited. The gripping jaws then return tQ the home position as shown in Figure 10 along the rever~e path of movement while remaining in their opened po6ition. The manner in which this motion i~ achieved will now be de6cribed etail, .: ~
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~5~77 Considering specifically Figure lO, the drive shaft of the respective cam 174, 194 and 216 rotates in a clock-wise direction. In the position shown in Figure lO, the cam 17~ is at a high, dwell position wherea3 the cam 19~1 i8 at a low, dwell position. As the shaft 176 commences its clock-wise rotation the bell crank 169 Will remain in the position shown in Figure lO. The follower 193 of the bell crank 191 will, however, reach a lobe on the cam l9'L and cause the bell crank 101 to be pivoted in a clock-wise direction about the pivot pin 192.
Initial pivotal movement of the bell crank 191 in a clock-wise direction i9 tran~mitted from its bifurcated arm 189 to the pin 188 to raise the block 185 away from a stop (not shown) upon which it rest0d. The block 157 is also resting against a stop in the Figure lO position which stop does not appear in the drawing~. There is a gap between abutting surfaces 231 of the block 157 and 232 of the Wock 185.
Therefore, initial upward movement of the block 185 will not be accompanied by any movement of the block 157. The relative movement between these blocks, however, causes a force to be exerted on the jaw actuating member 147 via the pin 206 fixed to the collar 205 carried by the block 185. This movement will cause the jaw actuating member 147 to pivot in the counter-clockwise direction as shown in Figure 8. This pivotal movement i8 trangmitted to an axially inward force on the operating rod 135 which causes the pins 132 and 133 to move inwardly. This movement of the pins 132 and 133 is transmitted into pivotal movement of the jaws 115 and 116 to cause the inserts 123 and lZ4 to move together to the clotted line position shown in Figure ~ to grip the .; I , . .
workpiece. Complete closure of the gripping mechani~m occurs before the block 185 contacts the block 157.
Upon continued rotation of the shaft 176 the bell crank 191 will be further pivoted and the ~urface 232 of the block 185 will contact the ~urface 231 of the block 157 resulting in upward movement of the block 157 along the rods 152 and 153, in the Y axis direction. The gripped workpiece will then be raised until the extreme l~it of travel, a~ determined by the height of the lift on the cam 104. During sub~tantially all OI this movement, thc cam 17~ -will have been in its dwell position and the bell cr~nk 10a will not pivot, l . ~ . , , ,, . . , "
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' '.;, 5~7 It should be noted that the pivoted blocking member 208 was held so that its lever portion 225 wa~ clear of the blocking member 224 by the contact o~ the pivoted blocking member portion 211 with the stop 212 carried by the lever 213. After the clearance between the surfaces 231 and 232 has been taken up, the blocking member 224 will be moved sufficiently so as to prevent any pivotal movement of the pivoting blocking member 208.
Continued rotation of the shaft 176 causes the cam 174 to move off of its high portion. The spring 195 therefore, exerts a force on the bell crank 169 to cause it to follow the profile of the cam 174 and pivot in a counter-clockuise direction. This puts a force on the follower members 165 and rods 161 anc~ 162 to cause the support arm 138 to move in the X direction from the home position to an extreme position.
During this movement, the jaws 115 and 116 will be retained in their closed position since there is no relative movement between the blocks 157 and 185. During the traverse of the gripping mechanism 114 and gripped workpiece in the ~ direction, the cam 1~4 will be at its high, dwell po~ition and no further movement in the Y
direction will occur.
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When the X direction has been traversed, the cam 174 reaches a lower . ;:
dwell position and the second lobe on the cam 194 operates on the bell erank 191 in conjunction with the spring 195 to cause pivotal movement in the counter-clockwise direction. The weight of the arm 135 and associated components, therefore, causes the workpiece, gripper mechanism 114 and blocks 157 and 185 to move downwardly along the rods 152 and 153. When the limit of travel in this direction is reached, the block 157 will contact the previously described stop and no further movementwill occur. The block 185 will, however, continue to move downwardly and cause , a force to be exerted from the collar 205 and pin 20B to the jaw actuating member 147.
The member 147 will now be pivoted again in a clock-wi6e direction and cause the jaws 115 and llB to open 80 that the workpiece is released from the gripping dies 123 and 124.
At the time that this releaae of the workpiece iB accompl~shed, the , .. . .
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cam 216 will have rotated BO that it~ high point is no longer in contact with the lever follower 215. The spring 221 will, therefore, have caused the lever 213 to pivot so that the stop surface 212 i9 clear of the pivoted blocking member portion 211.
As the shaît 176 continues to rotate, the block 185 will be raised as previously described by pivotal movement of the bell crank 191 in the cloclc-wise direction. At this point, however, the pivoted blocking member 208 will be moved by the ~pring 226 into registry with the block 224 to preclude relative movement between the blocks 185 and 157. Since this relative movement is precluded, the jaws 115 and 116 will be retained in their opened or released position. The gripping mechanism 114 is then moved sequentially along the Y axis to the upper extreme limit of travel : and then along the X axi~ to the innei~ e~treme level of travel. Subsequent movement causes the gripping mechanism 114 to be relowered again to the home position as shown in Figure 10. At this time, the cam 216 will have again returned to the position shown in Figure 10 and the block 185 will be permitted to move downwardly until it engages its stop while the block 157 is held slightly upwardly by its engagement with its respective stop. The mechanism then is ready for another cycle.
In the described operation the mechanism moves from a home position wherein the gripping mechanism is released, to a gripping position and then to a ~inal delivery position. The path of movement occurs generally first along the Y axis, then along the X axis, and finally along the Y axis. Reverse movement occurs in the opposite sequence, As has been previously noted, it is possible to cause the gripping to occur at the outer position and the release to occur at the inner position by merely rotating the cam 216 from the poaition shown in Figure 10 to a position displaced 180 2rom that position. Upon such reversal, the pivoted blocking member 208 will hold the jaw6 open in the Figure 10 position and prevent them from cloaing until the extreme outer position has been reached. Upon reaching that position, the workpiece . .
will be gripped and the jaws will be retained closed until the home poaition i3 again reached. ~t that point, the jaws will be permitted to open. It i~ believed that this aequence o2 operation may be ~eadily understood without further deacription.

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In describing the aforenoted mode of operation it has been assumed that all movement in the X axis occur~ before movement in the Y axis is initiated and vice versa. It should be readily understood, however, that merely changing the con-figuration of the cams 17~ and 19~ will alter this relationship OI movements.
In this embodiment the cam 194 has two lobes 50 that reverse movement occurs along the same path as outward movement occurred. By positioning a single lobe on the cam 194, however, movement in the following sequence can occur. The gripping mechanism 114 will be moved from the position shown in Figure 10 first along the ~ axis, secondly along the X axiæ and finally along the Y axis until the work position is reached. Return movement, however, will occur along the X axis so that the path traversed by the gripping mechanism 114 takes the form of a rectangle. With such a mechanism, the cam 216 pivoted block 208 and block 224 can be deleted.
~ ertain modifications in the operation of the device of Figures l-11 possible with the structure described have been previously mentioned. Various .
other modiffcations may be made without departing from the invention. For example, rather than using grippmg jaws, the relative movement between the blocks 185 and 157 may be used to operate a smail vacuum type pump. The gripping mechanism can, therefore, be of the suction type so as to eliminate the necessity for any mechanical engagement. It should ~lso be noted that all movement of the respective elementa is caused by springs or gravity. Therefore, if for any reason the gripping mechanism 114 o~ othex components encounter an obstacle, the mechanism will not jam. For example, if a larger than anticipated workpiece is positioned between the jaw dies 123 and 124, no crushing force will be exerted upon the workpiece. The relative movement between the blocks 185 and 157 will juat be atopped at an earlier time.

:,, .Furthermore, if the gripping mechanism 114 or other components engage an obstacle on their outward or downward movement, the respective bell cranks will move ~rea : ' of their respe tive cam surfaces and no force other than that exerted by the springa .- . .
1~5 and 1~8 will be placed against the obstacle.
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EMBODlM~NT OF FIGURES 12-16 A material handling apparatus in accordance with another embodiment of this invention is identified generally by the reference numeral 311. The material handling apparatus like the earlier embodiments is adapted to be used with a variety of machine tool or other operations for moving workpieces between respective positions. As example~ of applications for this device, the material handling apparatu~
311 may be used to pick workpieces from a storage bin and l~lace them onto a transfer table, remove workpieces from a transfer table or machine tool and place them on a conveyor, or move workpieces from one location to another in an assembly operation.
Various other applications for the material handling apparatus 311 will present them-selves to those sk;lled in the art.
The material handling apparatus 311 includes an outer housing assembly 312 having an input drive assembly 313. The input drive assembly 313 transfers drive from a suitable power source (not shown) via motion transfer means, to be described, to a gripper assembly, indicated generally b;y the reference numeral 314.
The gripper assembly 314 includes a pair of gripping jaws 315 and 31ff that are pivotally supported by means of pivot pins 317 and 318 upon a supporting member 319. The jaws 315 and 316 provide a detachable and adjustable connection to .
a respective pair of inserts 321 and 322. In this embodiment, the inserts 321 and 322 have facing cylindrical 6egmented ~urfaces 323 and 324 that are adapted to grippingly engage a workpiece.
The jaws 315 and 316 have inwardly projecting lever arm portions 327 and 328 that are received between a pair of facing ~houlders 329 and 331 of an actuating element 334 which is slidably 3upported within the supporting member 319. An operating rod 335 is affixed to the actuating element 334 for reciprocating it between an opened position. a~ ~hown in the view of Figure 1~, to a closed po~ition in which tho jaw in~erts 323 and 324 move togethær to grip a workpiece, The ~upporting member 3:l0 has a cylindrical trunion portion 336 that ia journaled in a complimentary surface of a eaddle 337. The saddle 337 iB integrally .

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7~'7 formed with an offset supporting arm 338. A clamping member 339 complete~ the support of the supporting member 319 and is affixed to the sAddle 337, by socket head machine acrews 341. Loosening of the machine screws 341 permit3 rotation of the supporting member 319 within the saddle 337 90 that the orientation of the jaws 315 and 316 may be adjusted relative to the remainder of the material handling apparatus 311.
The operating rod 335 i9 threaded and adjustably supports an internally threaded collar 342. Oppositely facing shoulders, 343 and 344 are formed by the collar 342. A bifurcated jaw actuating mechanism 347 is received between the shoulder9 343 and 344 and is pivotally supported on the arm 33a by means of a pivot pin 348.
Referring now in detail to Figures 15 and 16, the outer housing 312 defines an enlarged internal cavity 351. A pair of vertically extending supporting rods 352 and 353 are supported at the forward end of the outer housing 312 adjacent to an opening 350 formed in an arcuate forward wall 354 of the outer housing 312. At their upper ends, the ~upporting rods 352 and 353 are affixed to a cylindrical member 354 that is rotatably journaled, by means of an anti-friction bearing 355 in the upper wall , 356 of the outer,housing 312. The,lower ends of the rods 352 and 353 are also affixed :. .: . . , to a cylindrical member 357 that ~B journaled by means of an anti-friction bearing 358 in the lower housing wall 359.
The arm 33a iæ formed inwardly of the housing opening 351 with a vertically extending supporting block portion 3Sl. The supporting block 3~1 i8 formed with a pair of bores 362 and 363 for slidably supporting the block 361 and associated arm 338 upon the rods 352 and 353. The block 361, arm 338 and associated gripper mechanism 314 iB, therefore, supported for rectilinear movement in the Y axis direction relative to the outer housin~ 312.
A trunnion member 364 also has a pair of vertically extending bores and i8 slidably supported on the support rods 352 and 353 below the block 381. The trunion member 3~4 ha~ a pair of oppo~itely facing ahoulders 385 and 3~ that receive -lg-',1''- ' ' - , ,' ' .. :, , ~ : ,, . :

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1050~i77 therebetween a roller follower 367 that is carried at one end of a bell crank 3B8. The bell crank 368 is pivotally supported relative to the outer housing 312 by means of a pivot pin 369. The opposite arm of the bell crank 369 carries a roller follower 372 upon a pivot shaft 373. The roller follower 372 engages a first cam 374 of a timing mechanism, indicated generally by the reference numeral 375. The first cam 374 is affixed, in any known manner, to an input shaft 376 that is journaled by means of anti-friction bearings 377 and 378 affixed in side walls 379 and 3al of the outer housing 312. The end of the shaft 376 journaled by the bearing 378 extends into a gear housing 382 affixed, in any known manner, to the housing wall 381. The gear ~`
housing 382 forms a portion of the drive mechanism 313. The extending end of the shaft 376 carries a worm wheel 383 that is enmeshed with a driving work 384 for rotating the shaft 37S.
A crank arm 385 is affixed to the plate 357 in any known manner, as by welding. The crank arm 385 carries at its outer end an upstanding: ivot pin 386. One end of an adjustable link 387 is connected to the pivot pin 386 by means of a spherical bearing. The other end of the adjusting link 387 is pivotally connected by means of a pivot connection 388 to a lever, indicated generally by the reference numeral 391. The link 391 is pivotally supported on the outer housing wall 379 by means of a pivot pin 392. Intermediate its ends, the lever 391 carries a follower 393 that is engaged with a second timing cam 394 fixed to the shaM 376.
The follower 372 of the bell crank 3B8 is urged into engagement with it~

respective cam 374 by means of a tension sprin~ 395. One end of the tension spring 395 is affixed to the bell crank 368. The opposite end of the spring 395 is affixed to a lug 397 formed integrally with the side wall 381 of the outer housing 312.
In a like manner, the lever follower 393 is urged into engagement with its respective cam 394 by means of a pair of tension springs 398. One end of the tension : :
springs 398 are affixed to the lever 3al. The opposit~ ends of the springs 398 are connected to a lug 401 that is formed on the outer housing side wall 37a.
A blocking lever 408 i~ pivotally supported upon the block 331 by mean~ .
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A tension spring 421 is affixed to the lever 408 for urging its follower portion 415 into engagement with the segment 416. The opposite end of the tension spring 421 is affixed to the block 361.
Figures 12-16 show the material handling apparatus 311 in a home position with the gripping jaws 315 and 316 open. The apparatus 311 is set up in the illustrated embodiment to grip a workpiece in the position shown in the Figures 12-16, raise it, when viewed in accordance with Figure 15, along the Y axis, subsequently pivot the workpiece about the Y axis to an extreme position, and subsequently lower it re-traversing its movement along the Y axis where the piece is deposited. The gripping jaws then return to the home position as shown in Figure 15 along the reverse path of movement while remaining in their opened position. The manner in which this motion , is achieved will now be described in detail.
Considering specifically Figure 15, the drive shaft 377 and the respective cams 374 and 394 rotate in a clockwise direction. In the position shown in Figure 1~, the cam 394 is at a high, dwell position whereas the cam 374 is at a low, dwell position.
As the shaft 378 commences its clockwise rotation the cam 374 moves onto Rs ramp and effect pivotal movement of the bell crank 368 in a clockwise direction about the pivot pin 3B~. The follower 367 cooperates with the trunion surface 365 to raise the trunion member 364. Initial upward movement of the member 364 is accomplished while the block 361 remains in the po~itioll shown in Figure 15. Thus, this initial movemeDt causes a force to be exerted upon the gripper actuating lever 347. This force is transmitted to a pin 422 that i~ received in a V-shaped groove 423 of the block 412.
The pin 422 is amxed to the jPW actuating member 347. Thus, the jaw actuating - . . : :- , . ; - . : . :
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member 347 i9 pivoted in a counter-clockwi~e direction drawing the actuating rod 335 and operating member 334 inwardly. This inward movement causes the jaw~3 315 and 316 to pivot toward each other about the pivot pin~ 317 and 318 and grip a work-piece .
Upon continued upward movement, a stop on the trunion member 364 engages the block 361 and causes the block 361 to move upwardly in the Y axi3 direction along the rods 352 and 353. This upward movement causes the arm 337 and workpiece gripped by the jaw gripping mechanism 314 to be raised to an extreme upward position. When this position is reached, a dwell lobe on the cam 374 causes the bell crank 367 to be retained in its extreme clockwise pivotal position.
During the aforenoted movement, the cam lobe 394 was in a dw~ll poaition.
Subsequently~ however, it reaches a low position and the action of the springs 398 on the lever 391 causes it to pivot in a clockwise direction with the follower 393 following the surface of the cam 394. Thi~ pivotal movement i9 exerted through the link 387 onto the lever arm 385 to pivot the plate 357. Thi6 pivotal movement of the plate 357 i5 accompanied by rotation of the rod~ 352 and 353 and supporting mechanism carried thereby about a pîvot axis, which coincides w~th the Y a~is. During this pivotal move-ment, the jaws 315 and 316 remain in their closed position. When the gripping .
mechanism 314 and the associated workpiece have been rotated to the extreme limit of their movement, the c~m 394 will enter a dwell phase to hold the rods 352 and 353 and associate mechanism in the angular position.
The cam 374 will at this time have rotated to a po~ition in which the high lobe dwell portion i~ terminated and the lift will decrease. The spri=g 3~5 will urge the bell crank 36û in a counter clockwi~e direction and cause lowering of the trunion 364 and as~ociated block 361. Thi~ movement continue3 with both elements moving downwardly until the blocking lever 408, follower portion 415 contacts the upper surface of the plate 417. At this location, the segment 416 is free of engagement with the block~ng lever follow. r portion 415. The block 3Bl i~ precluded from downward movement and the trunion member 331 will continue to move downwardly to pivoS the , ' `'.
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':", ` ' ' ', lever 347 and cause the jaws 315 and 316 to reopen.
At this point, the spring 421 will cause the blocking lever 408 to pivot in a counter-clockwise direction so that the end portion 409 is positioned above the resilient stop block 412.
Continued rotation of the shaft 377 causes the cam 374 to reach another peak or lobe and cause the bell crank 368 to be pivoted again in a clockwise direction.
When this occurs, the trunion member 364 will move upwardly. Any substantial lost motion between the member 364 an~ the block 361 will be precluded, however, due to the interposition of the blocking lever portion 409 above the resilient stop block 412.
Thus, the block 361 will move upwardly along the Y axis substantially immediately upon raising of the trunion member 364 and without any substantial relative motion therebetween. Therefore, the jaws 315 and 316 will be retained in their open position during the reverse travPl. Once the motion in the Y axis has been traversed, the cam 394 will again actuate the lever 391 to rotate the rods 352 and 353 and associated mechanism carried thereby back in the pivotal direction around the Y axis to its home position.
~ 'hen the mechanism is again lowered, the blocking lever follower portion 415 will again engage the segmented plate 416 to cause pivotal movement so that the jaws 315 and 316 are triggered so that they will be free to close during the next repeat .. . .
cycle, as aforede3cribed.
In describing the aforenoted mode of operation it has been assumed that all linear movement in the Y axis occurs before rotary motion about the Y axis is initiated. It should be readily understood, however, that merely changing the con-figuration of the cams 374 and 394 will alter this relationship of movement~. By changing the location of the 6egment 41B from the position shown to the oppo6ite extreme position, the rever~al between the point of gripping and release may be altered. At the same time, it may be de6irable to reverse the rotation of the shaft 377 to effect reverse movement o~ the mechani~m.
Certain modi~ications in the operation of the embodiment of Figures 12-la possible with the structure described have been previously mentioned. ~larious othcr ~,1 . . . . .

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, ~L~S~7 modifications may be made without departing from the invention. For example, ratherthan using gripping jaws, the relative movement between the trunion 364 and block 381 may be used to operate a small vacuum type pump. The gripping mechanism can, therefore, be of the suction type so as to eliminate the nec0ssity for any mechanical engagement. It should also be noted that all movement of the respective elements i8 caused by springs or gravity. Therefore, if for any reason the gripping mechanism 314 or other components encounter an obstacle, the mechanism will not jam. For example, if a larger than anticipated workpiece is positioned between the jaw dies 321 and 322, no crushing force will be exerted upon the workpiece. The relative -~
movement between the trunion 364 and block 361 will just be stopped at an earlier time. Furthermore, if the gripping mechanism 314 or other components engage an obstacle on their outward or downward movement, the respective bell cranlcs will move free of their respective cam surfaces and no force other than that exerted by the springs 395 and 398 will be placed against the obstacle.
It is to be understood that the foregoing description is that of preferred embodiments of the invention. Various changes and modifications may be made witho~t departing from the spirit and scope of the invention as defined by the appended claims.

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Claims (16)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A material handling apparatus for moving workpieces or the like between a first location and a second location, gripping means, supporting means supporting said gripping means for movement between a gripping position in which a workpiece is gripped and a released position, said supporting means being movable to position said gripping means in said first location and in a second location, single drive means including an element movable between a first position and a second position, means including a lost motion connection operably connecting said drive means element to said supporting means for moving said gripping means between said first location and said second location in response to movement of said drive means element, said lost motion connection being effective to permit movement of said drive means element from a position inter-mediate its first position and its second position to its first position when said gripping means remains in its first location, actuating means responsive to the movement of said drive means element from its intermediate position to its first position relative to said gripping means for moving said gripping means from one of its positions so the other of its positions, locking means for retaining said gripping means in its other position upon movement of said gripping means from its first location to its second location, and means responsive to the movement of said gripping means to its second location for releasing said locking means and permitting said actuating means to move said gripping means from its other position to its one position.

2. A material handling apparatus as set forth in claim 1 wherein the gripping means comprises a pair of pivotally supported jaws.

3. A material handling apparatus as set forth in claim 1 wherein the drive means element moves the gripping means rectalinearly between its first location and its second location.

4. A material handling apparatus as set forth in claim 3 wherein the drive means element additionally moves the gripping means in a transverse direction from its first location to its second location.

5. A material handling apparatus as set forth in claim 4 wherein the gripping means comprises a pair of pivotally supported jaws.

6. A material handling apparatus as set forth in claim 2 wherein the supporting means comprises a tubular member supported for movement between a first position and a second position, the jaws being pivotally supported by the tubular member.

7. A material handling apparatus as set forth in claim 6 wherein the actuating means comprises a cam member slidably supported within the tubular member and having a cam engagement with said jaws, said cam member being movable relative to said tubular member upon the occurence of the lost motion permitted by said lost motion connection.

8. A material handling apparatus as set forth in claim 7 wherein the locking means comprises a detent lock for locking said cam means in engagement with the jaws for retaining the jaws in their gripping position, said detent lock being movable between its locked position and a released position in response to return movement of the gripping means to its second location.

9. A material handling apparatus for moving workpieces or the like between a first location and a second location, gripping means, supporting means supporting said gripping means for movement between a gripping position in which a workpiece is gripped and a released position, said supporting means being movable to position said gripping means in said first location and in said second location, first motion transfer means for moving said supporting means in a first direction between a first extreme position and a second extreme position, second motion transfer means for moving said supporting means in a second direction between a first extreme position and a second extreme position, said second direction being angularly related to said first direction, single drive means including an element movable between a first position and a second position, timing means for operating said motion transfer means so that said supporting means is moved in sequence by said motion transfer means from its first location to its second location, said timing means including a lost motion connection operably connecting said drive means element to at least one of said motion transfer means, said lost motion connection being effective to permit movement of said drive means element from a position intermediate its first position and its second position to its first position when said gripping means remains in its first location, actuating means responsive to the movement of said drive means element from its intermediate position to its first position relative to said gripping means for moving said gripping means from one of its positions to the other of its positions, locking means for retaining said gripping means in its other position upon movement of said gripping means from its first location to its second location, and means responsive to the movement of said gripping means to its second location for releasing said locking means and permitting said actuating means to move said gripping means from its other position to its one position.

10. A material handling apparatus as set forth in claim 9 wherein the first motion transfer means includes a first carriage movable in the first direction and restrained against movement in the second direction.

11. A material handling apparatus as set forth in claim 10 wherein the second motion transfer means includes a second carriage supported by the first carriage for movement in the second direction and restrained against movement relative to the first carriage in the first direction.

12. A material handling apparatus as set forth in claim 11 wherein the first direction is in the Y-axis and the second direction is in the X-axis.

13. A material handling apparatus for moving workpieces or the like between a first location and a second location, gripping means, supporting means supporting said gripping means for movement between a gripping position in which a workpiece is gripped and a released postion, said supporting means being movable to position said gripping means in said first location and in said second location, first motion transfer means for moving said supporting means in a first direction betweeen a first extreme position and a second exteme position, second motion transfer means for pivotally moving said supporting means in a second direction between a first extreme position and a second exteme position, said second direction being angularly related to said first direction, single drive means including an element movable between a first position and a second position, timing means for operating said motion transfer means so that said supporting means is moved in sequence by said motion transfer means from its first location to its second location, said timing means including a lost motion connection operably connecting said drive means element to at least one of said motion transfer means, said lost motion connection being effective to permit movement of said drive means element from a position intermediate its first position and its second position to its first position when said gripping means remains in its first location, actuating means responsive to the movement of said drive means element from its intermediate position to its first position relative to said gripping means for moving said gripping means from one of its positions to the other of its positions, locking means for retain-ing said gripping means in its other position upon movement of said gripping means from its first location to its second location, and means responsive to the movement of said gripping means to its second location for releasing said locking means and permitting said actuating means to move said gripping means from its other position to its one position.

14. A material handling apparatus as set forth in claim 13 wherein the first motion transfer means includes a first carriage movable in the first direction and restrained against movement in the second direction.

15. A material handling apparatus as set forth in claim 14 wherein the second motion transfer means includes an element supporting the first carriage for movement in the second direction.

16. A material handling apparatus as set forth in claim 15 wherein the first direction is parallel to the pivot axis of the second direction.