US 3561614 A
Description (OCR text may contain errors)
United States Patent Yoshitomo Tezuka;
Munehiro Namba, Tokyo, Japan 813,205
Apr. 3, 1969 Feb. 9, 1971 Kabushiki Kaisha Aida Tekkosho Kanagawa-ken, Japan Inventors Appl. No. Filed Patented Assignee ARTICLE TRANSFER APPARATUS ADAPTED TO CYCLICALLY TRANSFER AN ARTICLE FROM A POSITION TO ANOTHER POSITION 3 Claims, 6 Drawing Figs.
Int. Cl B66c 1/02 Field of Search 2 1 4/ 1 BS3,
 References Cited UNITED STATES PATENTS 3,010,587 11/1961 Hollinger 214/](B3) 3,232,446 2/1966 Spurr 214/1 (B4) 3,459,313 8/1969 Upton 214/1 (84) Primary ExaminerGerald M. Forlenza Assistant Examiner-George F. Abraham Attorney-Holman, Glascock, Downing & Seebold ABSTRACT: An article transfer apparatus for cyclically transferring an article from one position to another position in which an article retained in a holder is transferred from one position to another position while being moved in one and the same plane.
ARTICLE TRANSFER APPARATUS ADAP'IED TO CYCLICALLY TRANSFER AN ARTICLE FROM A POSITION TO ANOTHER POSITION The present invention relates to an article transfer apparatus.
In a cyclic operation in a press, for example, it has been conventional practice for several types of transfer apparatus to be employed in combination for transferring the blank or -cle transfer apparatus whereby an article held in a holder may be transferred from one position to another in one and the same plane while being held in position by the holder.
A further object of the present invention is to provide an intermittent reciprocal drive mechanism for the article transfer apparatus so that the apparatus may cyclically transfer an article.
A still further object of the present invention is to provide an article transfer apparatus provided with an over load safety device adapted to stop the operation of the entire transfer apparatus when the article holder is subjected to an abnormal load or, impact so that the internal mechanisms of the apparatus may be effectively protected from possible damage.
According to the present invention, there 'is provided a cyclic article transfer apparatus comprising a stationary arm fixedly secured to the framework of the apparatus; a first drive shaft rotatably supported by one end of the arm; a first rocking arm fixedly secured atone end to the first shaft for rocking in one and the opposite directions with respect to the stationary arm; a second hollow shaft mounted over the first shaft in concentric relation thereto and having a sprocket or gear fixedly mounted thereon; a third hollow shaft rotatably supported by the other end of the first rocking arm and having a sprocket or gear mounted thereon, the sprocket or gear on the second shaft and the sprocket or gear on the third shaft being operatively connected to each other; a second rocking arm fixedly secured at one end to the third shaft for rocking movement in one and the opposite directions with respect to the first rocking arm; a fourth shaft fixedly secured to the other end of the first rocking arm and disposed within the third shaft in concentric relation thereto the fourth shaft having a sprocket or gear fixedly mounted thereon; a fifth shaft rotatably supported by the other end of the second rocking arm and having a sprocket or gear fixedly mounted thereon, the sprocket or gear on the fourth shaft and the sprocket or gear on the fifth shaft being operatively connected to each other; and an article retaining holder operatively connected to the fifth shaft.
The above and other objects and advantages of the present invention will be more readily apparent to those skilled in the art from the following description taken in conjunction with the accompanying drawings which illustrate a preferred embodiment of article transfer apparatus constructed in ac cordance with the present invention and in which:
FIG. 1 is a diagrammatic fragmentary front elevational view of the preferred embodiment of article transfer apparatus;
FIGS. 2A, 2B, 2C, 2D, 2E and IF are diagrammatic views on a reduced scale which show the transfer apparatus shown in FIG. I in different operative positions, respectively;
FIG. 3 is a fragmentary view partly in vertical section and partly in elevation of essential parts of the transfer apparatus on an enlarged scale;
FIG. 4 is a partly in elevation and partly in cross section view of the overload safety device of the transfer apparatus as seen from the left hand side of FIG. 3;
FIG. 5 is a fragmentary elevational view of the intermittently reciprocal drive mechanism of the article transfer apparatus showing the interior of the drive mechanism; and
FIG. 6 is a sectional view taken substantially along the line IV-V of FIG. 5 the view looking in the direction of the ar rows.
Referring to the drawings and more particularly to FIGS. I and 2 wherein one preferred form of article transfer apparatus is diagrammatically illustrated, the transfer apparatus generally comprises a hollow stationary arm I fixedly secured to one of the machine frames (not shown), a first hollow rocking arm 2 pivoted at one end to the lower end of the stationary arm I, a second hollow rocking arm 3 pivoted at one end to the other end of the first rocking arm 2 and a suction or gripping type article holder 4 pivoted at one end to the other end of the second rocking arm 3 and adapted to hold an article to be transferred. The first rocking arm 2 is adapted to be reciprocally rocked through an arc of about on the pivot point with respect to the stationary arm I by a drive mechanism, as will be described hereinafter, and as the first rocking arm 2 is reciprocally rocked, the second rocking arm 3 and holder 4 are caused to rock on their pivot points in succession. The opposite ends of the reciprocal rocking movement stroke of the first and second rocking arms 2 and 3 and holder 4 are shown by broken lines in FIG. I and they may rock between the opposite ends of the stroke from the left to the right and vice versa to transfer an article held by the holder 4 from one position to another. Various different suc' cessive positions of the first and second rocking arm 2 and 3 and holder 4 which may be assumed in their rocking movement between the opposite ends of the stroke are diagrammatically shown in FIGS. 2A, 2B, 2C, 2D, 2E and 2F.
Turning now to FIGS. 3 and 4 in which one form of the connection between the hollow stationary arm I, hollow first and second rocking arms and 3 and holder 4 is more clearly shown, the stationary arm I and first and second rocking anns 2 and 3 are illustrated as being in parallelism to one another.
A hollow transverse shaft 5 is rotatably mounted at the lower end of the arm 7 by means of bearings 6 and the shaft has one end fixedly secured to the lower end of the first rocking arm 2 by bolts. A sprocket 7 is fixedly mounted on the hollow shaft 5 within the lower end of the stationary arm I and the sprocket is adapted to have an intermittently reciprocal movement in one direction and the other direction imparted thereto via a drive mechanism, as will be described hereinafter, by a chain 8 trained over the sprocket and drive mechanism.
A transverse shaft I0 having an axially extending central bore 48 and being of lesser diameter than the shaft 5 is rotatably received in the shaft 5. The shaft 10 is joumaled at the inner end within the lower end of the first rocking arm 2 by bearings 9. The outer periphery of the outer end of the shaft 10 is provided with splines 11, and an adjusting flange I2 having splines in its inner periphery is keyed to the shaft I0 by means of these splines. A plurality of angularly spaced slots I3 extend through the thickness of the flange I2 and are in align ment with corresponding threaded bores 3' in the lower end of the stationary arm I. Bolts 14 are threaded through the slots 13 in the flange I2 and the threaded bores 3' in the lower end of the stationary arm thereby securing the flange I2 to the stationary arm 1. With the above arrangement of the connection between the stationary and first rocking arms 1 and 2, the position of the first rocking arm 2 with respect to the stationary arm I can be easily and rapidly adjusted by first loosening the bolts 14 and then moving the rocking arm 2 with respect to the stationary arm I.
A sprocket I5 is fixedly secured to the outer periphery of the inner extension of the shaft II) which is disposed within the lower end of the first rocking arm 2. The upper end of the first rocking arm 2 (as seen in FIG. 3) is provided with bearings 17 and a transvers hollow shaft I6 is rotatably mounted in the bearings 17. Theright end of the shaft 16 is fixedly secured to the adjacent end of the second rocking arm 3. A sprocket I8 is fixedly secured to the outer periphery of the shaft I6 within the first rocking arm upper end and a chain 19 is trained over the sprockets l8 and 15. A transverse shaft of lesser diameter the shaft 16 is loosely received within the shaft l6 and its respective ends beyond the ends of the transverse shaft l6 and the opposite sides of the rocking arm 2. The right end of the shaft 20 extends into the adjacent end of the second rocking arm 3 and a bevel gear 2i is secured thereto. A shaft 23 ex tends longitudinally within the arm 3 and is joumaled at the opposite ends within the rocking arm in bearings 22 which are in turn suitably supported within the arm 3. The upper end of the shaft 23 has a bevel gear 24 secured thereto and the bevel gear meshes with the bevel gear 21. The lower end of the shaft 23 has a bevel gear 25 secured thereto which meshes with a bevel gear 28 fixedly mounted at a point adjacent to the right end (as seen FIG. 3) of a transverse shaft 27 which is in turn joumaled within the lower end of the arm 3 in bearings 26 suitably supported within the lower end of the arm 3. The right end of the transverse shaft 27 is provided on its outer periphery with splines 29 and an annular flange 30 having an internally splined boss is keyed to the shaft 27 by the coacting splines. Similarly, an annular flange 30' having an internally splined boss is keyed to the other end of the shaft 27 which is also provided on its outer periphery with splines 29'. An articl holder 4 having a pair of integral mounting arms 31 is fixedly secured to the flanges 30 and 30' by the mounting arms 31.
The left end (as seen in FIG. 3) of the shaft 20 extends beyond the adjacent end of the hollow shaft 16 and the ad jacent side of the first rocking am 2 and is provided with splines 32 on its outer periphery. An annular flange 33 having an internal spline is keyed to the shaft 20 by the coacting splines. A disc 37 is rotatably supported on the outer side of the upper end of the arm 2 adjacent the splined end 32 of the shaft 20. The flange 33 is fixedly secured to the outer side of the disc 37 by a plurality of bolts 36 (see FIG. 4) threaded into mating threaded bores in the disc 37 through elongated slots 35 in the flange 33. With this arrangement, the position of the article holder 4 with respect to the arm 3 can be easily and quickly adjusted. For this purpose, the bolts 36 are first loosened and the flange 33 is then manually turned through a desired angle. As the flange 33 is turned its rotation is transmitted through the bevel gears 21 and 24, shaft 23, bevel gears 25 and 28 to the shaft 27 whereby the article holder 4 may be turned to a desired angular position with respect to an article (not shown) to be gripped or held by the holder 4.
The disc 37 has a rod 38 projecting therefrom and which extends along the arm 2 in spaced relation thereto. The lower end of the rod 38 is held by a pair of oppositely disposed heads 4i (FIG. 4) which are in the direction of the rod 38 by a pair of springs 40. The heads 41 and the springs are received in a pair of mounting blocks 39 provided in a bracket 39 suitably secured to the arm 2. The extreme end of the rod 38 is provided with a recess 42 for partially receiving a ball check valve 46 which normally closes an air release bore 44 by the action of a spring 45 mounted in the bore of a valve block 43 also secured to the bracket 39. The bore 44 is connected through a pipe 437 which extends into the check valve block 43 to the central bore 48 in the shaft 10. The central bore 68 communicates via a conduit 39 with an emergency stop relay (not shown) of a main machine, such as a press.
FIGS. 5 and 6 illustrate one form of drive mechanism which is adapted to impart an intermittently reciprocal movement to the sprocket 7.
The drive mechanism generally comprises a transverse drive shaft 5H adapted to have a continuous rotational movement imparted thereto in one direction from a conventional motor (not shown) through conventional reduction gearing (not shown). The drive shaft 51 is supported in a frame 5 5 by bearings 52 suitably mounted within a bearing box 52 secured in the frame 54 in a conventional manner. A disc-type stationary cam 53 is fixedly supported in the frame 54 in concentric relation to the drive shaft 5i and has a pair of cam faces 55 and 56 formed by cutting the outer periphery of thecam at two diametrically opposite portions thereof. Two stationary cam plates 57 and 58 are fixedly secured to the frame 54 above and below the cam 53, respectively, and have cam faces 59 and 60 which are opposite to and at the same distance from the respectively adjacent cam faces 55 and 56. A lever 61 is keyed at one end to the drive shaft 51 and one end of a link 63 is to the free end of thelever 61. The other end of the link 63 has a stub-shaft 64 extending laterally of the link and is provided with a roller 65. The roller 65 is in contact with the outer periphery of the disc cam 53 and tracks the periphery of the cam 53. The shaft 64 is pivotably connected with one end of a connecting rod 66 and the other end of the connecting rod 66 is pivotably connected to a transverse stub-shaft 72 supported in a chain manipulation member 73 to which the opposite ends of the chain 8 are anchored. The chain 8 is trained over the sprocket 7 and a free sprocket 69 is mounted on a transverse stub-shaft 67 supported in the frame 54v Assuming that the center point in the distance between the. axes of the shafts 64 and 72 at the opposite ends of the connecting rod 66 is R and the radius of the roller 65 r, the cam faces 55 and 56 are arcuate surfaces having radii of R r and R r respectively, while the cam faces 59 and 60 are parallel surfaces apart from the respectively adjacent-cam faces 55 and 56 by a distance corresponding to the diameter of the roller 65.
The lever 61 secured to the drive shaft 51 is adapted to continuously rotate together with the link 63 in a predetermined direction as the drive shaft 51 rotates and as the lever 6lrotates and, accordingly, the link 63 rotates the roller 65 riding on the disc cam 53 and the roller is caused to rotate along the outer periphery of the cam 53. Therefore, the end of the connecting rod 66 remote from the end connected to the link 63 imparts a reciprocal movement to the chain'8. The connecting rod 66 is raised while the roller 65 is rolling along the portion a b of the cam 53 to drive the chain 8 in the direction of the arrow x as shown in FIG. 5. While the roller 65 is rolling along the portion b c of the cam 53, since the connecting rod 66 merely rocks on the shaft 72 as a fulcrum to the right, the chain 8 remains at rest. On the other hand, while the roller 65 is rolling along the portion 0 d of the cam 53, the connecting rod 66 drives the chain 8 in the direction of the arrow v as viewed in FIG. 5. Finally, while the roller 65 is rolling along the portion d 0, since the connecting rod 66 merely rocks on the shaft 72 as a fulcrum to the left, the chain 8 has no motion imparted thereto. The rotation angle of the link 63 with respect to the lever 61 is so controlled that the roller 65 may not come off the periphery of the cam 53 while the roller is rolling along the portion a b and c d of the cam:
outer periphery. Thus, it will be understood that the chain 8 can have imparted thereto a unique intermittent movement by a cyclically repeating movement in one direction, rest, movement in the opposite direction and rest in that order. The time period during which the chain 8 is at rest each time can be determined by the length of the cam faces 55 and 56.
In the arrangement shown in FIG. 3, although sprockets,-
chains and gears are employed in combination for transmitting movement between adjacent associated shafts, for the'same purpose only one type of the above-mentioned three types of transmission devices may be employed.
In operation, the chain 8 has first imparted thereto movement in one direction by the intermittent drive mechanism as shown in FIGS. 5 and 6 and the thus driven chain in turn drives the sprocket 7 over which the chain 8 is trained in the same direction. The rotation of the sprocket 7 in this direction causes the first rocking arm 2, which is integrally secured to the sprocket 7 to pivot on the shaft 10. The rocking of the arm 2 causes rotation of the sprocket 18, because the chain 19 is trained over the sprocket i5 and the sprocket 18. Since the sprocket 18 is integrally secured to the shaft 16, the rotation of the sprocket 18 causes the outer shaft I6 to rotate on its axis and the shaft in turn causes the arm 3 to rock as the second arm is integrally secured to the shaft 16.
As the arm 3 is rocked with respect to the arm 2, the bevel gear 24 in mesh with the bevel gear '21 which is in turn integrally secured to the arm 2 is rotated. The rotation of the bevel gear 24 is transmitted to the shaft 27 at the remote end of the arm 3 by means of the shaft 23, and bevel gears 25 and 28. The rotation of the shaft 27 on its own axis causes the article holder 4 fixed thereto to rotate.
When the ratio of the diameter of the sprocket 69 to that of the sprocket 7 is selected as l l, the ratio of the diameter of the sprocket to that of the sprocket 18 is selected as 2 l and the ratio of the bevel gear21 to that of the bevel gear 28 is selected as lzl, the article holder 4 may maintain its constant disposition at all times with respect to an article to be transferred by the apparatus in various different operative positions and such a constant disposition of the article holder 4 is illustrated as being parallel to the horizontal plane of FIGS. 1 and FIGS. 2A to 2E inclusive illustrate the article holder 4 at various stages in the movement from the starting point to the terminating point of the stroke as the sprocket 7 is rotated in one direction, while FlG. 2F illustrates the article holder 4 at the start of its return movement form the terminating point of the stroke to the starting point as the sprocket 7 is rotated in the opposite direction. As seen in these FIGS. throughout an article transfer cycle, the first and second rocking arms 2 and 3 may at all times constitute the equal side relations of regular triangles thereby moving the article holder 4 in one and the same plane. For simplification of the illustration and disclosure, means which assists the article holder 4 in gripping or holding at the starting point of the movement stroke and means which assists the holder 4 in releasing the gripped or held article at the terminating point of the movement stroke are neither illustrated nor described.
When the article holder 4 is subjected to any abnormal load or impact, such a load or impact is transmitted to the shaft 27 on which the holder is mounted, but the load or impact may be transferred from the shaft through the bevel gear arrangement 28, 25, the shaft 23 and the bevel gear arrangement 24, 21 to the shaft 20. Hence, the rod 38 of the flange 37 is caused to swing laterally in one direction (see FIG. 4) against the force of one of the pairs of springs-40 which urges the rod in one lateral direction so as to forcibly open the ball check valve 46 against the action of the spring 45 which normally'urges the ball check valve to the closed position, whereby air within the air conduit 47 is allowed to escape into the atmosphere through the central bore 48 in the shaft 10. As the result of a escape of air from the air conduit 47, the air pressure within the system including the air conduit drops so as to actuate an emergency stop relay (not shown) to which the system is connected and the thus actuated relay stops the operation of the entire transfer apparatus. v
As clear from the foregoing, according to the present invention, the first and second rocking arms are connected to each other in such a manner that they may rock relative to each other and travel in one and the same and one plane while holding an article to be transferred thereby and accordingly, the transfer of an article from oneposition to another predeter mined position and the release of the article at the predetermined position can be performed by means of simple mechanisms. Therefore, the novel article transfer apparatus can be quite conveniently employed in connection with the operation of a press line in which it is necessary to transfer a material or blank to a press, and disc harge a complete product from the press to a location at which the product is subjected to a further process.
Although one preferred embodiment of the present invention has been illustrated and described herein, it is to be understood that the same is illustrative in nature and not necessarily for limiting upon the scope of the teaching in its broader aspect. Many additional variations and changes in the embodi ment within the scope of the appended claims will occur to those skilled in the art.
l. A cyclic article transfer apparatus comprising a framework, a stationary arm fixedly secured to the framework; a first shaft rotatably supported by one end of said arm; a first rocking arm fixedlysecurcd at one end to said first shaft for rocking movement in one and opposite directions with respect to said stationary arm; a second shaft fixed to said stationary arm and extending within said first shaft; a motion transmission means fixedly mounted on said second shaft; a third shaft rotatably supported by the other end of said first rocking arm; said a motion transmission means fixedly mounted on said third shaft; said motion transmission means on the second shaft and said motion transmission means on the third shaft being operably connected to each other; a second rocking arm fixedly secured at one end to said third shaft for rocking movement in one and opposite directions with respect to said first rocking arm; a fourth shaft fixedly secured to said other end of the first rocking arm and disposed within said third shaft in concentric relation to the third shaft; a motion transmission means fixedly mounted on said fourth shaft; a fifth shaft rotatably supported by the other end of said second rocking arm; a motion transmission means fixedly mounted on said fifth shaft; said motion transmission means on the fourth shaft and said motion transmission means on the fifth shaft being operably connected to each other; and an article retaining holder operably connected to said fifth shaft.
2. The cyclic article transfer apparatus as claimed in claim 1, including means for driving said first shaft in one and opposite directions comprising a drive shaft adapted to rotate continuously in one fixed direction; a lever fixedly connected to said drive shaft; a connecting rod; a link connecting one end of said rod to said lever; a chain for driving said first shaft, the other end of the rod being connected to the chain; a disc cam fixedly secured to said framework in concentric relation to 1 said drive shaft; a roller pivoted to said link and riding along the outer periphery of said disc cam; said disc cam having diametrically opposite cam faces on its outer periphery, each having a radius greater than that of the remainder of disc cam, and two cams fixedly secured to said framework at positions apart from said cam faces of the disc cam respectively by a distance corresponding to the diameter of said roller.
3. The cycle article transfer apparatus as claimed in claim 1, in which a rod extends from said fourth shaft which extends through said third shaft; said rod being held on opposite sides by inwardly biased springs and a check valve engageable with the lower end of said rod and serving to allow an emergency stop and control air to escape into the: atmosphere.