Apparatus for intermittently rotating and moving a member

A rotary transfer member carries means for picking up a sheet-like article from the top of a supply stack supported within a hopper having an open top and an open bottom. An indexing mechanism includes means for intermittently rotating an output shaft in response to a continuously driven input shaft, and the transfer member is supported for rotation with the output shaft and also for axial movement relative to the output shaft. The transfer member is moved axially in response to linear movement of a follower which engages a cam connected for continuous rotation with the input shaft. Supply stacks of articles are successively elevated into the hopper from an index table by a power driven jack mechanism, and a set of magnets are positioned adjacent the hopper for magnetically spreading and spacing the articles within the upper portion of the supply stack within the hopper.

BACKGROUND OF THE INVENTION 
In the feeding or supply of metal sheet-like articles or blanks to a 
machine or press where one or more operations are performed on each 
article, it is commonly desirable to supply or transfer the articles to 
the press in a successive manner and at a high rate of speed so that 
optimum performance can be obtained from the press. It is also desirable 
for the feeding or transfer mechanism to operate in a continuous and 
dependable manner without interruption so that there is no down time of 
the press which receives the articles. 
Frequently, it is necessary to supply or feed sheet-like articles such as 
flat blanks to a press by picking up each sheet from the top of a supply 
stack, moving the sheet laterally or horizontally to a predetermined 
location and then lowering the sheet onto a feeding mechanism which 
successively feeds the blanks or sheets into the press. Furthermore, it is 
usually desirable for the articles or sheets to be transferred from the 
supply stack to the press in precise timed relation with the operation of 
the press. 
SUMMARY OF THE INVENTION 
The present invention is directed to improved apparatus for successively 
transferring articles from a storage or supply station to another station 
where the article receives one or more operations. Apparatus of the 
invention is particularly adapted for successively transferring articles 
at a high speed and in timed sequence with another power driven machine 
and is also adapted for dependable operation so that the articles are 
transferred without skipping or interruption. In addition, the apparatus 
of the invention provides for precision movement of each article along a 
predetermined path and for precisely positioning the article at a 
receiving station. 
Other advantages and features of the invention and the specific 
construction of one embodiment will be apparent from the following 
description, the accompanying drawing and the appended claims.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The apparatus illustrated in FIG. 1 is adapted for successively 
transferring articles A in the form of flat oval metal blanks on sheets 
from a supply stack S to a mechanism (not shown) for feeding a press 
having a die set for forming each sheet into an end wall of a muffler. 
However, while each article A is illustrated in the form of a flat oval 
blank or sheet, it is to be understood that the article may be of a 
different shape or configuration. 
As shown in FIGS. 2 and 3, the stack S of flat ferrous metal sheets A are 
confined within a hopper 15 formed by two sets or pairs of vertical guide 
rods 16 positioned at opposite ends of the stack. Each pair of guide rods 
16 is supported by an L-shaped bracket 18 which is mounted on a horizontal 
support plate or platform 19 for lateral or horizontal adjustment by a set 
of screws 21 extending through corresponding slots within the base portion 
of the bracket. A set of four rectangular permanent magnets 25 are 
supported in horizontally spaced generally opposing relation on opposite 
sides of the stack S by corresponding L-shaped brackets 26 which are also 
secured to the platform 19 by sets of screws 27 extending through 
corresponding slots within the base of the brackets 26. 
Preferably, the magnets 25 are of the type manufactured and marketed by 
Bunting Magnetics Co., Franklin Park, Ill. and are effective to induce a 
magnetic field within the sheets A so that the sheets within the upper 
portion of the stack are separated and spaced vertically apart in a 
logarithmic manner and the sheets remain in parallel vertically spaced 
relation. This magnetic separation of the sheets within the upper portion 
of the stack assures that two adjacent sheets do not stick together as a 
result of oil or other forms of surface adhesion. 
A set of four dogs or pawls 32 are positioned adjacent the bottom of the 
hopper 15, and each pawl 32 is pivotally supported by a corresponding 
horizontal pin 33 secured by a bracket 34 depending from the stationary 
platform 19. The pivot pins 33 are located so that the weight of each pawl 
32 normally positions the pawl as shown in FIG. 3 where the pawl engages 
the bottom article or sheet A within the stack S and rests against a 
corresponding stop pin 36. 
A rotary indexing trasport member or table 40 is positioned below the 
hopper 15 and includes sets of upwardly projecting rods 42 which are 
interconnected by cross-members 43, 44 and 46 to form nests for receiving 
a plurality of supply stacks S of sheet A. The stacks S are angularly 
arranged in a spoke-like manner on the annular table 40, and are 
successively located or positioned directly under the hopper 15 in 
response to indexing of the table 40 by a suitable power indexing drive 
(not shown). 
A mechanical elevator or jack actuator 50 (FIG. 3) is positioned below the 
transport table 40 and under the hopper 15, and includes a circular head 
member 52 secured to the upper end of a helical ball screw 53 which 
receives recirculating balls (not shown) confined within a rotary nut 
driven by a reversible drive motor 55. Preferably, the jack actuator 50 is 
of the ball screw actuator type, for example, as manufactured and marketed 
by Duff-Norton Company, Charlotte, N.C. A set of circular holes 56 are 
formed within the indexing table 40 directly under the centers of the 
stacks S of sheets A, and each hole 56 is adapted to receive the head 52 
of the jack actuator 50 when the head member 52 is raised for elevating a 
stack of articles on the table 40 into the hopper 15. 
Referring to FIGS. 1 and 4, a rotary indexing unit or mechanism 60 includes 
a housing 62 which is mounted on a frame (not shown) and supports a 
rotatable input shaft 64 and a rotatable tubular output shaft 66. 
Preferably, the general construction of the indexing unit or mechanism 60 
is similar to that shown in U.S. Pat. No. 2,986,949 which issued to 
Commercial Cam and Machine Company, Chicago Ill. The indexing mechanism 60 
provides for indexing the output shaft 66 in angles of predetermined 
degrees in response to continuous rotation of the input shaft 64. A double 
cam member 68 is secured to the input shaft 64 for rotation therewith and 
has outer peripheral cam surfaces 69. A cam follower 72 includes a 
plurality of axially spaced sets of rollers 73 for engaging the outer cam 
surfaces 69 of the cam members 68. The cam member 68 and the cam follower 
member 72 cooperate to prevent back lash or relative play when the 
follower member 72 is rotatably indexed in response to continuous rotation 
of the cam member 68 and thus provides for precision rotation of the 
output shaft 66. 
The output shaft 66 includes an enlarged cylindrical lower portion 76 which 
supports an elongated upper plate 77. A pair of parallel spaced vertical 
guide rods 81 have their upper end portions rigidly secured to the plate 
77 and project downwardly into corresponding antifriction sleeve-type ball 
bearings 82 which are supported by an elongated lower plate 84. Thus the 
plates 77 and 84 rotate with the output shaft 66 of the indexing mechanism 
60, and the lower plate 84 is supported for vertical movement relative to 
the upper plate 77. Preferably, the plates 77 and 84 are constructed of 
aluminum to minimize their mass. 
An elongated transfer member or arm 90 has its center portion rigidly 
secured to the lower plate 84, and a pair of oval shaped suction units 92 
(FIG. 1), having resilient oval lips 93, are secured to the opposite end 
portions of the transfer arm 90. Compressed air is supplied to the 
transfer arm 90 through an air supply tube 94 (FIG. 1) and a rotary union 
96 located on the axis of rotation, and the compressed air is passed 
through a venturi to generate a suction within each suction unit 92 when 
it is positioned over the hopper 15. The pressurized air supply is also 
alternately supplied directly to each suction unit 92 when it is 
positioned 180.degree. from the hopper 15, as will be explained later. 
Referring to FIG. 4, an elongated vertical rod 102 extends through the 
tubular output shaft 66 of the indexing mechanism 60 and has its lower end 
portion connected to the lower plate 84 through an anti-friction thrust 
bearing 103 and a nut 104. A linear actuating unit or mechanism 110 
includes a box-like housing 112 which is secured to the housing 62 of the 
indexing mechanism 60 and encloses a cylindrical barrel-type cam member 
114 which has a peripherally extending cam groove or surface 116. The cam 
member 114 is rigidly secured or connected to the input shaft 64 of the 
indexing mechanism 60 and is driven with the cam member 68 at a constant 
rpm by a drive unit 120. 
The housing 112 of the linear actuating mechanism 110 also supports a pair 
of horizontally spaced vertical guide rods 122 which receive a 
corresponding pair of sleeve-type anti-friction ball bearings (not shown) 
retained within a follower block 124 rigidly connected to the upper end 
portion of the actuating rod 102. The block 124 supports a roller-type cam 
follower member or element 126 which projects horizontally into the cam 
groove 116 of the cam member 114. 
In operation of the article transfer apparatus described above, the input 
shaft 64 is driven at a constant speed by the drive 120 which may be an 
extension from the main drive of another machine such as a punch press. 
The cam members 68 and 114 are designed so that the output shaft 66 is 
indexed in increments of 180.degree. with a dwell between each indexing 
movement. The cam member 114 produces vertically reciprocating movement of 
the plate 84 and the transfer arm 90 during each dwell of the indexing 
mechanism 60. When the transfer arm 90 descends, the suction unit 92 
overlying the hopper 15 is effective to pick up the uppermost blank or 
sheet A on the stack S within the hopper 15. After the transfer arm 90 
ascends to the position where the lower plate 84 is substantially adjacent 
the upper plate 77, the transfer arm is rotated or indexed 180.degree. by 
the mechanism 60 so that the blank or sheet A is carried to a receiving 
station, for example, above a feed mechanism (not shown) which 
successively feeds the sheets into a punch press. 
When the transfer arm 90 again descends, air pressure is created within the 
suction unit 92 at the receiving station so that the transferred sheet A 
is released from the suction unit and deposited on the sheet feeding 
mechanism. Simultaneously, the suction unit 92 on the opposite end of the 
transfer arm 90 picks up the uppermost sheet A within the stack S within 
the hopper 15 as a result of a suction created in the suction unit, and 
the cycle is repeated. As mentioned above, successive stacks of blanks or 
sheets A are supplied to the hopper 15 in response to a proximity sensor 
130 which senses the level of the sheets A within the hopper 15 and 
controls the operation of the indexing drive for the table 40 and the 
drive 55 for operating the jack actuator 50. 
From the drawings and the above description, it is apparent that transfer 
apparatus constructed in accordance with the present invention, provides 
desirable features and advantages. For example, the combination of the 
rotary indexing unit or mechanism 60 and the linear actuating unit or 
mechanism 110 provides for a precision high speed transfer of a succession 
of articles when it is desirable to transfer each article along a path 
which requires vertical or "X" movement as well as horizontal or "Y" 
movement. Furthermore, the combined mechanisms produce the X-Y transfer 
path at a high speed in response to continuous rotation of the input shaft 
64. For example, it has been found that the combined mechanisms provide 
for easily transferring metal blanks or sheets A at a speed of one sheet 
per second and for depositing each sheet in a precise position at the 
receiving station. In addition, the two separate cam members 68 and 114 
provide for conveniently and independently selecting or changing the "X" 
path and the "Y" path to produce a desired transfer path. It is also 
understood that the rotary indexing mechanism 60 may be constructed to 
produce intermittent rotary oscillatory movement as well as intermittent 
rotary indexing movement. 
As another important advantage, the mechanisms 60 and 110 cooperate with 
the article supply hopper 15 and article spacing magnets 25 to assure that 
the articles or sheets are successively transferred in a rapid manner 
without interruptions and with optimum dependability so that continuous 
operation of the press which receives the articles is assured. 
While the indexing mechanism 60 and the linear actuating mechanism 110 are 
illustrated in a machine for successively transferring flat sheets A from 
the supply hopper 15, it is apparent that the combined mechanisms may be 
used in other machines or apparatus which require X-Y transferring or 
advancement of one or more articles. Furthermore, while the form of 
transfer apparatus herein described constitutes a preferred embodiment of 
the invention, it is to be understood that the invention is not limited to 
this precise form of apparatus, and that changes may be made therein 
without departing from the scope and spirit of the invention as defined in 
the appended claims.