Article exchanging grapples
United States Patent 1 Ars&#39;eneault 1 1 ARTICLE EXCHANGING GRAPPLES [75] Inventor: Paul J. Arseneault, Boulder, C010.  
 [73] Assignee: International Business Machines Corporation, Armonk, NY.  
  221 Filed: Nov. 30, 1973 211 Appl. No.: 420,507  
 [52] US. Cl 214/1 B; 198/20 R; 214/152;  
  294/99 R [51] Int. Cl. 865g 37/00 [58] Field of Search 294/99, 33, 86.32;  
 214/1 B, l BA,1 BB,1 BC. 1 BD,l52; 198/20, 22. 24. 25. 103, 107  
 Primary E.raminer-Frank E. Werner Attorney. Agent, or FirmHomer L. Knearl 1H1 3,880,294 51 Apr. 29, 1975 [57] ABSTRACT Article exchanging grapples are disclosed herein for handling cylindrical objects such as film or tape cartridges, spherical objects or rectangular articles. The fingers of the grapples are shaped so that they substantially conform to a portion of the article being gripped except at the tips of the fingers. The tips are shaped to depart from the surface of the article gripped so as to provide a space for inserting fingers of another grapple. The fetching grapple has the same shaped fingers as the holding grapple. The fingers of the grapples are spring loaded so that when they are not holding an article the normal position of the fingers is slightly less than the cross-sectional width of the article to be held or exchanged. To exchange an article, the fetch grapple moves toward the article held by the hold grapple. The fetch grapples fingers contact the article and move along the surface of the article until they interpose themselves between the article and the tips of the fingers of the hold grapple. As the fetch grapple continues to move forward its fingers penetrate between the article and the fingers of the hold grapple spreading the fingers of the hold grapple away from the article. The fetch grapple has now become the hold grapple and can withdraw with the article in its grip.  
 9 Claims, 9 Drawing Figures PMENTEU APR 2 91975 SHEET 10F 3 Fl G FIG.3  
 PIC-3.2  
 saw 3 or 3 FIG. 5  
 FIG. 6  
 ARTICLE EXCHANGING GRAPPLES BACKGROUND OF THE INVENTION This invention relates to improvement in grapples and more particularly to grapples shaped to cooperate with each other whereby two grapples may repeatably exchange an article between them.  
  The art is replete with single function grapples designed to grip objects. Some of these grapples have fingers with slightly flared tips. The function of the tips is to guide the fingers of the grapple around the article being gripped by the grapple. None of these grapples can be used in a double function role whereby an article might be exchanged from one grapple to another grapple. There is no known grapple having fingers biased and shaped in such a way that an exchange function might be performed between two grapples.  
  It is the object of this invention to provide at least a pair of grapples having their fingers shaped and biased so that they may repeatably exchange an article between them.  
 SUMMARY OF THE INVENTION In accordance with this invention the above object has been accomplished by shaping the fingers ofa grapple so that they conform to the surface of the article being exchanged in the region of the end of the fingers except that the tips of the fingers are shaped to provide an open region between the fingertips and the surface of the article. In addition. the fingers of each grapple are biased in a normal position to be slightly less than the width of the article being gripped. Thus when an article is held by a grapple the fingers are biased slightly wider than normal. Further. when a fetching grapple contacts the article to be exchanged it will be biased by the surface of the article to a wider position as it approaches the tips of the fingers of the holding grapple. Due to the open space between the tips of the holding grapple and the article. the fetch grapple fingers will penetrate between the article and the fingers of the holding grapple thereby releasing the grip of the holding grapple and transferring the article to the fetching grapple. The grapples being identical in configuration. the fetch and hold roles may be interchanged depending on which grapple is presently holding the article.  
  The advantage of this invention is its simplicity of operation and construction. Because of the simplicity of operation. the unit is highly reliable and may be cycled millions of times without failure. Because of its simple construction, the cost of manufacturing this article exchanging apparatus is extremely low. For these reasons the invention is very attractive with regard to any automated article handling apparatus such as magnetic tape cartridges. photographic film cartridges. bottles. cans. and so forth.  
  The foregoing and other objects. features and advantages of the invention will be apparent from the following more particular description of preferred embodiment of the invention as illustrated in the accompanying drawings.  
 BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an article exchange station utilizing the grapple of the present invention.  
 FIG. 2 shows one preferred embodiment of the article exchanging grapple.  
  FIG. 3 shows another preferred embodiment of the article exchanging grapple.  
  FIGS. 4A. 4B. and 4C show the article exchanging grapple of FIG. 2 in operation.  
  FIG. 5 shows a grapple designed in accordance with this invention for handling spherical objects.  
  FIG. 6 shows a scissors-type grapple designed in accordance with this invention wherein the bias of the grapple fingers is provided by a spring. The grapple shown is shaped to handle rectangular objects.  
  FIG. 7 shows the position of grapple fingers in FIG. 6 at the beginning of an exchange operation.  
 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. I, one possible environment for use of the article exchanging grapples will be described. Article 10 being exchanged could be the can. a capsule or a cartridge. The exchange takes place between a grapple I2 linearly movable and grapples I4. lb or 18 which are rotary movable. The grapples I2, l4. l6 and 18 are shaped in the form of a clip with a curvature so that they will conform substantially to the side-walls of the cartridge I0.  
  Before the exchange operation shaft 20 is rotated to index one of the clips I4. 16. or I8 into position opposite clip 12 holding cartridge I0. Clip 12 mounted on a slide mount 22 may then be moved linearly forward towards clip I4. Slide mount 22 is mounted in a dovetail slide 24 for stability.  
  The exchange of cartridge I0 from clip I2 to clip I4 occurs when the fingers of clip [4 slip between the cartridge I0 and the fingers of the clip I2. The cooperation between the clips and cartridge to perform the cartridge exchange operation will be described shortly with respect to FIGS. 4A through 4C: however. before describing the details of the operation. reference is made to FIGS. 2 and 3 that show alternative preferred embodiments for the clip grapple of FIG. I.  
  In FIG. 2 the clip grapple has relatively thick fingers 26 that taper from the back of the grapple to the tips of the fingers. The tips of the fingers at their inside surface have a flat 28. This flat is in contrast to the general curvature of the inner surface 30 of the fingers. As will be shown shortly. the flat 28 provides the space between the surface of the article being handled and the tip of the fingers of the grapple. The grapple of FIG. 2 is made of a resilient material so as to provide springloading of the fingers 26 when the grapple is holding an article such as cartridge 10 in FIG. 1. The resilient material might. for example. be plastic.  
  In FIG. 3 a grapple is shown that could be stamped and formed from sheet metal. The grapple has fingers or arms 32 formed on a curve from the back portion 34 of the grapple to the tips of the fingers 32. The tips depart from the curvature of the arms 32 and have an inner flat face 36. The flat face 36 forms an open space between the arms 32 and the article being held by the grapple in order to facilitate article exchange between grapples.  
 OPERATION OF PREFERRED EMBODIMENT In FIGS. 4A through 4C the operation of the clip grapple of FIG. 2 is shown. In FIG. 4A clip grapple 38 is shown gripping a cylindrical article 40. A fetch clip 42 is shown in position opposite the hold clip 38. To perform an article exchange operation. clip 42 is moved towards clip 38. Because clip 42 is not loaded with an article. the normal position for its arms or fin gers 44 is such that the distance between the tips 46 is less than the diameter of the article 40. Arms or fingers 39 of clip 38. on the other hand. are biased slightly wider than the normal position because clip 38 is holding article 40. The relative positions of arms 39 of clip 38 and arms 44 of clip 42 during the beginning of an exchange operation is shown by arms 44 in phantom in FIG. 4A.  
  The exchange operation begins by arms 44 penetrating between article 40 and arms 39. Because arms 39 have the flat 48 on their inside face. the tips 46 of arms 44 can interpose themselves between the arms 39 and the article 40. As clip 42 moves to the left. tips 46 are deflected they slide along the surface of article 40. Sliding along the surface of the article 40. tips 46 move between arms 39 and the article 40 lifting the arms 39 away from the article as shown in FIG. 4B.  
  In FIG. 4B the clip 42 has moved completely forward until the back of the clip engages the front surface of the article 40. In this position arms 44 are now complctely gripping the article 40 while arms 39 of clip 38 have been biased away to release article 40. The biasing of arms 39 to release article 40 is accomplished by arms 44 interposing themselves between the article 40 and arms 39. The exchange is completed in FIG. 4C by clip 42 withdrawing from clip 38. Article 40 is now held by arms 44. The article moves with clip 42. and the exchange is complete.  
  The roles of clips 38 and 42 in FIG. 4C have now reversed from their roles in FIG. 4A. Thus. if another article exchange were desired. clips 38 and 42 would be moved back together again. Clip 38 now being in the normal unloaded position would have its arms 39 less spread apart than arms 44. Thus. when the clips move together again. arms 39 would interpose themselves be tween article 40 and arms 44. The article 40 would be gripped by arms 39 and arms 44 would release. This exchange operation could be repeated any number of times. Because ofthe simplicity of the structure. the re liability of the article exchange apparatus is extremely high. Exchange operations numbering in the millions without failure have been accomplished by these grapples.  
 DETAILED DESCRIPTION OF ALTERNATIVE EMBODIMENTS While the invention has been described with reference to cylindrical articles and with reference to clip grapples having two fingers or arms. it will be apparent to one skilled in the art that any shape object or article might be interchanged between grapples in accordance with this invention by redesigning the shape of the fingers of the grapples. All that is necessary for successful operation is that the fingers grip some portion of the article being transferred and that the tips of the fingers be shaped so as to provide a slight open space between the surface ofthe article being transferred and each finger. This open space is necessary so that a fetch grapple seeking to pick up the article from a holding grapple can interpose its fingers between the article and fingers of the holding grapple. Of course. for the fetch grapple to interpose its fingers. the fetch grapple must be aligned with the fingers of the holding grapple.  
  In FIG. 5. an alternative embodiment of the invention for gripping and exchanging spherical objects is shown.  
 Identical grapples and 52 have four fingers each. Grapple S0 is holding sphere 54 with its fingers 56. Grapple 52 has fingers 58. identical to the lingers S6 of grapple 50. Each of the fingers 56 and 58 have a slight reverse curvature at their tips. This curvature provides the open space between sphere 54 and the fingers when the fingers are gripping the sphere. The exchange operation for the grapples of FIG. 5 would be identical to the exchange operation previously discussed. with reference to FIGS. 4A through 4C. The only difference is that a spherical article is being exchanged and that more fingers are involved.  
  It will be appreciated by one skilled in the art that any number of fingers might be used in a grapple in accordance with the invention. Preferably the fingers conform to at least a part of the object being exchanged so that a good grip on the object is obtained by the holding grapple. In addition. as previously discussed. the tips of the fingers should have a flat or reverse curvature so as to provide open space between object and fingertips to aid the exchange operation. Further. while the object 54 in FIG. 5 is spherical. it will be apparent to one skilled in the art that an elliptical object. or any irrcgu lar curved object. might be exchanged by the grapples. so long as the grapples have an over-center type of grip on the article to hold it. and the article can bias the grapple fingers to change the width of the opening between grapple fingers. A fetch grapple can then interpose its fingers between the article and the fingers of a holding grapple.  
  In FIG. 6 a spring&#39;loaded grapple is shown handling a rectangular article. Block 60 is being held by grapple 62. Grapple 64 is in position to penetrate and withdraw block 60 from grapple 62. Grapples 62 and 64 are slightly different than previously described grapples. in that their jaws are rigid. and the springforce applied to the jaws is provided by springs 63 and 65. Each spring 63 or 65 is a tension spring tending to close the jaws of the grapples.  
  Normal position for the grapples is defined by a post 66 or 76 positioned adjacent the spring in each grapple. For example. post 66 in grapple 64 is attached to jaw 68 and acts as a stop for spring 65 pulling jaw 70 towards jaw 68. This defines a normal closed position for the arms 68 and 70. In this position the mouth of the jaws is slightly more narrow than the diagonal width of the block 60 to be gripped. This is due to the scissortype action of the arms at 68 and 70 being pivoted about pin 72. Jaws 74 and 76 of grapple 62 operate in identically the same manner and have a post 76 to define their normal position when they are not gripping a block.  
  An exchange operation with the grapples 62 and 64 begins with grapple 64 moving forward to engage the surfaces of block 60. The tips ofjaws 68 and 70 of grapple 64. and jaws 74 and 76 of grapple 62. are similarly flared. The flare is for the purpose of providing open space between the surfaces of block 60 and jaws of a grapple holding the block. laws of a fetching grapple can then slide along the surface of a block until its tips interpose themselves between the block and the tips of the holding grapple. Thus. grapple 64 would move to the right with its jaws 68 and 70 penetrating between block 60 and jaws 74 and 76 of grapple 62. Grapple 64 effectively causes the jaws of grapple 62 to release block 60 by the interposition of its own jaws. With block 60 released from grapple 62. and now gripped by the jaws of grapple 64. grapple 64 would withdraw. taking block 60 with it. Block 60, if desired. could be passed back to grapple 62 by moving the grapples together again.  
  The interaction between the jaws of grapples 62 and 64 in FIG. 6 is shown in FIG. 7 where a detail ofthe interaction between jaw 70 and jaw 74 is diagrammed.  
  As depicted in FIG. 7. grapple 64 (FIG. 6) has moved to a point where the tips of its jaws have contacted the surface of block 60. but block 60 is still being held by grapple 62 (FIG. 6). Jaw 74 of grapple 62 holds block 60 by means of its contact with the side-wall of the block 60 and its flared tip 78 which is gripping a corner of block 60. Jaw 70 is sliding along the face of block 60 as the fetching grapples moves towards the holding grapple. The flared end 80 of arm 70 will slip under the flared end 78 of arm 74 as the fetching grapple penetrates its jaws under the jaws of the holding grapple. As jaw 70 continues to move forward. jaw 74 is lifted off block 60 and flared end 80 slips around the corner of the block 60 to hold block 60. Jaw 70 has now released block 60 from the grip of arm 74. and when grapple 64 (FIG. 6) withdraws. block 60 will move with grapple 64.  
  It will be appreciated by one skilled in the art that if heavy objects are being exchanged. a support floor for the objects will be necessary and the grapples will merely be sliding the objects across the floor as they move forward and backward. Further. while the invention has been particularly shown and described with reference to preferred embodiments and alternative embodiments thereof. it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.  
 What is claimed is:  
  1. Article exchanging grapples for exchanging articles between a hold grapple and a fetch grapple wherein the roles of the grapples are interchangeable and each grapple comprises:  
 fingers for gripping the surface of an article being held. said fingers being spring loaded so that the normal separation between fingers. when not biased by an article held by the fingers. is less than the width of the article to be exchanged;  
 the tips of the fingers being shaped to provide an open space between the surface of the article held and the tip of the fingers of the holding grapple. whereby in an exchange operation the fetch grapple fingers will move along the surface of the article as the grapples are moved together until the fetch grapple fingers enter said open space and penetrate between the article and the fingers of the holding grapple.  
  2. The grapples of claim I wherein said fingers are shaped near their tip to conform to the surface of the article to be exchanged.  
  3. The grapples of claim 2 wherein said tip of the fingers has an inner face flattened forming a discontinuity with the remainder of the inner face at the tips of the fingers so that said fingers near their tip conform to the article surface and then open away from the article surface to provide said open space when each of said grapples is holding an article to be exchanged.  
  4. The grapples of claim 2 wherein said tips of the fingers have a curvature that is directed outward from the inner face of the fingers so that said fingers near their tip conform to the article surface and then open away from the article surface to provide said open space.  
  5. Article exchanging apparatus for exchanging objects of cylindrical. spherical. rectangular shape or any combination shape thereof comprising:  
 first grappling means having a means for gripping the object to be exchanged; said gripping means having a means for spacing an interactive portion of said gripping means away from the surface of the object being held by said gripping means; said gripping means being spring loaded to a first position so that a mouth formed by the gripping means is less than the cross-sectional width of the object to be exchanged. said gripping means when holding an object being biased to a second position wider open than said first position; second grappling means having substantially the same means as said first grappling means; movable mounting means for moving said first and second grappling means toward each other with said gripping means of both grappling means aligned for interaction. said first grappling means holding an object and having said gripping means in said second position. said second grappling means having said gripping means in said first position; said gripping means of said second grappling means penetrating the interactive portion of said gripping means of said first grappling means as the two grappling means move together and interact so that the object biases the gripping means of the second grappling means wider open to the second position to grip the object. and the gripping means of the second grappling means. in turn. bias the gripping means of the first grappling means wider open to release the object. 6. The object exchanging apparatus of claim 5 wherein said gripping means comprises:  
 jaws shaped to conform to at least a portion of the object near the tip of the jaws; said jaws being made of a resilient material so that when the jaws are deflected from the first position by the object to be exchanged. the jaws are spring loaded. 7. The object exchanging apparatus of claim 5 wherein said gripping means comprises:  
 rigid arms conforming near the tips of the arms to at least a portion of the object. said arms being spring loaded by a tension means attached to the arms. 8. Method for exchanging an article between two grapples wherein the grapples have fingers of substantially the same shape whereby the article exchanging grapples exchange the role of holding grapple and fetching grapple. as well as the article during the exchange operation. said method comprising the steps of: inserting the arms of the fetching grapple in an open space between the article and the arms of the holding grapple; penetrating the arms of the fetching grapple between the article and the arms of the holding grapple; gripping the article with the arms of the fetching grapple and simultaneously biasing the arms of the holding grapple with the arms of the fetching grapple so that the holding grapple releases the article whereby the fetching grapple may withdraw from 7 8 the holding grapple with the article so that the artipreach each other; Cle Exchange clmplewd and the cmhlmgc sliding the arms f the fetching grapple along the surroles of the grapples is completed. 9. The method of claim 8 wherein the step of inserting comprises:  
 aligning the arms of the fetching grapple with the thc llmclc and the arms Ohhe hc&#39;ldmg pp arms nf the holding grapple as the grapples upface of the article until the arms of the fetching grapple are inserted into the open space between