GB2100708A

GB2100708A - A materials-handling machine

Info

Publication number: GB2100708A
Application number: GB08212405A
Authority: GB
Inventors: Torre Giancarlo Della
Original assignee: Rockwell-Rimoldi SpA
Current assignee: Rockwell-Rimoldi SpA
Priority date: 1981-06-23
Filing date: 1982-04-29
Publication date: 1983-01-06
Also published as: IT1138809B; JPS586850A; DE3223241A1; IT8122518A0; FR2508016A1

Abstract

A materials-handling machine comprises a device for individually separating and removing flexible workpieces from a stack. The device comprises a pick-up unit (3) carrying a plurality of pick-up heads (5) thereon. Each of the pick-up heads (5) is provided with at least one pin element (15) projecting downwardly from its lower surface and at least one angularly disposed pin element (16) mounted within each head (5) for movement between an inner withdrawn position and an extended position, in which they protrude from the lower side of the heads. The vertically fixed pin (15) is the first to engage the uppermost piece in a stack and the angularly disposed pin elements (16) are caused immediately thereafter to move to their extended positions so as in combination with the fixed pin element (15) to provide a positive gripping action for removal of the uppermost workpiece from a stack. <IMAGE>

Description

SPECIFICATION A materials-handling machine The present invention relates to a materialshandling machine and, more particularly, to a machine provided with a device for removing workpieces sequentially from a stack and then carrying them to a location, where they are deposited, for example, onto conveying means to advance them to positions for receiving additional manufacturing operations.

Devices for removing workpices from a stack and then relocating them for receiving further manufacturing operations are well known; however, devices which utilize protruding pin elements to engage and remove the uppermost piece from a stack have been known to displace or cause a slipping of the piece upon initial engagement by the pin elements. Such a condition may result in incorrect engagement by the lifting head of the device as well as in the subsequent improper positioning of the removed piece that should be receiving further manufacturing operations.

United States Patents 3 386 763, 3 981 495 and 4 008 888 show and describe devices for removing pieces from a stack.

According to the present invention, there is now provided a materials-handling machine comprising a base member, a carousel rotatably mounted thereon for supporting a plurality of stacks of flexible articles and for bringing the stacks successively to an unloading station, and an unloading device for effecting sequential removal of flexible articles from a stack when at the unloading station, the device comprising a pick-up unit operatively connected to the base member for alternate vertical movement towards and from the upper surface of the stack, at least one pick-up head mounted on and for movement with the pickup unit for engaging the uppermost article of the stack, means connected to the pick-up head for fixing the position of the uppermost article on the stack, and means mounted in the pick-up head in operative association with the fixing means for removing the uppermost article from the stack on movement of the pick-up unit therefrom.

In a preferred embodiment, the pick-up unit carries a plurality of pick-up heads and is alternately raised from and thence lowered to a position, in which the pick-up heads are caused to engage the uppermost piece in a stack. Each pick-up head is provided with at least one vertically fixed pin element projecting from its lower surface and one or more angularly disposed pins mounted within each pick-up head for movement between an inner withdrawn position and an extended position, in which they protrude from the lower sides of the heads. Immediately after engagement of a workpiece by the fixed pin, a pneumatic cylinder is actuated to cause a coil spring to move the angularly disposed pins to their extended position, in which they are caused to engage the workpiece.The initial engagement of a workpiece by the fixed pin prevents displacement of the workpiece and the combination of engagement by the fixed pin and by the angularly disposed pins provides a positive and accurate means for removing a workpiece and relocating it for further manufacturing operations.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a materials-handling machine embodying the present invention, Figure 2 is a view in side elevation of a pick-up unit of the machine, Figure 3 is a plan view of the pick-up unit shown in Fig. 2, Figure 4 is an end view partially in section of a pick-up head carried by the pick-up unit, Figures 5 and 6 are sectional views on lines V-V and VI-VI, respectively, in Fig. 4 and Figure 7 is a perspective view showing further details of one of the elements within a pick-up head.

Referring now to the drawings, Fig. 1 shows a materials-handling machine provided with a workpiece separating and removing device which is identified generally by numeral 1 and includes a horizontal arm 2 having a pick-up unit 3 operatively connected to one end thereof. The opposite end of this horizontal arm 2 is connected to a vertical rod 4 which is reciprocatable by drive means (not shown). The pick-up unit 3 supports a plurality of pick-up heads 5, which are caused to engage the uppermost surface of a stack 7 when the vertical rod 4 is caused to move downwardly. The stack 7 is made up of workpieces 6 and supported on a plate member 8 provided with closely associated guide elements 9 for retaining the stack of superposed workpieces in alignment. When the vertical rod 4 is caused to move upwardly, the heads 5 remove the uppermost workpiece 6 from the stack 7.After raising the workpiece, the pick-up unit 3 is rotated to a position, in which the heads 5 are caused to release the removed workpiece at a location (not shown), from which it can be advanced to receive additional operations.

The cycle is then repeated until all the workpieces 6 have been removed from the stack 7. The pick-up unit 3 is always lowered the same distance to engage the respectively uppermost workpiece and as each workpiece is removed, the plate 8 is raised by a rod 10 through a distance which compensates for the thickness of a removed workpiece. The raising of the plate 8 in this manner permits the pickup unit 3 to be consistently lowered a con stant amount onto the stack 7.

The plate members 8 are carried on a carousel 11 which is caused to rotate about a central rod 1 2 fixed to a base member 1 3.

After removal of all the workpieces 6 from a stack 7, the carousel 11 is rotated by means not shown about the central rod 1 2 until another stack 7' comes into vertical alignment with the pick-up unit 3. The device then resumes its function of lowering and raising the pick-up unit 3 to effect sequential removal of individual workpieces 6 from the newly located stack 7'.

As shown in Figs. 2 and 3, the pick-up unit 3 is operatively connected to the horizontal arm 2 by means of a damper element 1 4 of an elastomeric material to provide the pick-up unit 3 with a self-aligning feature that will be more fully described hereinafter. This damper 9 is provided with a plurality of stress-reliev ing notches or channels arranged on opposed sides thereof and perpendicularly to the longitudinal axis of the damper. These stress-reliev ing notches serve to align the pick-up heads 5 with the upper surface irregularities of the stack 7 so as to provide positive engagement of all the pick-up heads with the upper workpiece 6.

Each pick-up head 5 is provided with at least one vertically disposed fixed pin element 1 5 which projects from the lower surface of the pick-up head. Additionally, each pick-up head 5 includes at least one angularly disposed pin 1 6 mounted within it for movement between an inner withdrawn position and an extended position, in which these pins 1 6 protrude from the lower surface of the heads 5.

As shown in Figs. 4, 5 and 6, three angularly disposed pins 1 6 are mounted in a support member 1 7 which is pivotably mounted on a rod member 1 8. The support member 1 7 is provided with a finger 1 9 extending generally upward therefrom into operative association with a piston rod 20 of a pneumatic cylinder 21.

During its outward stroke, the piston rod 20 is caused to press against the finger 1 9 (Fig.

6) and is effective in locating the pins 1 6 in a withdrawn position within the pick-up heads 5. When the piston rod 20 is caused to move inwardly on its return stroke, a coil spring 22 interposed between the support membr 1 7 and the upper internal surface of the pick-up head 5 causes the support member 1 7 to be pivoted to a position. in which the angularly disposed pins 1 6 are in their extended position and protrude from the lower surface of the pick-up head 5.

As shown in Fig. 5, the pneumatic cylinder 21 is threaded and can be selectively located longitudinally by means of a lock nut 23.

Such adjustment varies the amount of movement, through which the finger 1 9 is caused to move by the piston rod 20 and in turn controls the distance the pins 1 6 are caused to protrude from the lower surface of the pickup heads 5.

Additional control of the extent of protrusion of the pins 1 6 is provided by means of manual rotation of a disc element 17' which projects from the pick-up head 5. This disc element is operatively associated with a pivot pin 18' disposed eccentrically with respect to the rod member 1 8, on which the support member 1 7 is rotatably mounted. The disc element 17' can be rotated about the axis of the pivot pin 18' between extreme positions defined by shoulders A and B (Fig. 7), which are engageable with a stop pin C carried in one of the side walls of the pick-up head 5.

Each position of the disc element 17' corresponds to a selected position of the eccentric pin 1 8' and to a pre-determined extent of projection of the pins 1 6 from the lower surface of the pick-up head 5 when the support member 1 7 is rotated by the coil spring 22.

As shown in Fig. 3, four pick-up heads 5 are mounted adjacent each of the ends of a pair of spaced parallel rod members 3'. The pick-up heads 5 are fixed on these rod members 3' by a pressure clamping device comprising a spring-loaded rod 24 provided with an inclined planar surface 25, which is caused to engage a surface of conforming configuration provided on each rod member 3'.

The engagement of these planar surfaces is promoted by a coil spring 26 (Fig 5) mounted on the rod 24 and is effective in maintaining the lower surface of the pick-up heads 5 horizontal.

To change the position of the pick-up heads 5 on the rod members 3', so as to accommodate larger or smaller workpieces, a push button 27 is depressed, which is formed at one end of the rod 24. This releases the contact between the inclined planar surfaces and the pick-up heads 5 can be selectively slid to any desired position. Upon release of the push button 27, the biasing force acting on the rod 24 returns the inclined planar surfaces into engagement which locks the pick-up heads 5 in their selected position.

When the pick-up unit 3 is lowered, the fixed pin elements 15, extending from their respctive pick-up heads 5, are caused to penetrate the uppermost workpieces 6 of the stack 7. Immediately after the penetration by the pin elements 15, the pneumatic cylinder 21 of each pick-up head 5 is actuated to cause the piston rods 20 thereof to be retracted.

Retraction of the piston rods 20 permits the spring 22 to pivot the support members 1 7 to a position, in which the angularly disposed pins 1 6 are caused to penetrate the uppermost workpiece 6.

This manner of engaging a workpiece provides positive engagement by each pick-up head 5 for the fixed pin element 1 5 tends to prevent any possible displacement of a workpiece while the angularly disposed pins 1 6 are caused to penetrate the latter.

As shown in Fig. 3, the pick-up heads 5 are arranged in pairs and the angularly disposed pins 1 6 are directed in opposite directions in each pair, as shown in Fig. 2. This arrangement of the pins 1 6 provides positive pick-up of the workpieces when the pick-up unit 3 is raised.

After the pick-up unit 3 has been raised, it is rotated to release the removed workpiece in a position, from which it will be advanced to receive further manufacturing operations. To release the removed workpiece from the pickup heads 5, the pneumatic cylinder is actuated so that the piston rod 20 moves outwardly. This movement of the piston rod pushes on the finger 1 9 and pivots the support member 1 7 to a position, in which its angularly disposed pins 1 6 are in a withdrawn position within their respective pick-up heads 5.

Claims

1. A materials-handling machine comprising a base member, a carousel rotatably mounted thereon for supporting a plurality of stacks of flexible articles and for bringing the stacks successively to an unloading station, and an unloading device for effecting sequential removal of flexible articles from a stack when at the unloading station, the device comprising a pick-up unit operatively connected to the base member for alternate vertical movement towards and from the upper surface of the stack, at least one pick-up head mounted on and for movement with the pickup unit for engaging the uppermost article of the stack, means connected to the pick-up head for fixing the position of the uppermost article on the stack, and means mounted in the pick-up head in operative association with the fixing means for removing the uppermost article from the stack on movement of the pick-up unit therefrom.

2. A machine as claimed in claim 1, wherein the pick-up unit comprises a pair of spaced parallel rod members and wherein a respective pick-up head is mounted in opposed relation adjacent each end of each rod member.

3. A machine as claimed in claim 2, the fixing means comprising a fixed pin element projecting downwardly from the lower surface of each pick-up head.

4. A machine as claimed in claim 1, the removing means comprising a support member pivotably mounted within each pick-up head, at least one angularly disposed pin mounted in each support member, means to so pivot each support member as to cause the or each pin to protrude from the lower surface of the pick-up heads, and means to return the or each pin to a withdrawn position within the pick-up heads.

5. A machine as claimed in claim 4, said pivoting means comprising a spring mounted within each pick-up head in operative association with each support member.

6. A machine as claimed in claim 4, said returning moving means comprising a pneumatic cylinder having a piston rod operatively connected to the support member.

7. A machine as claimed in claim 4, wherein the angularly disposed pins of opposed pick-up heads are directed in opposite directions when protruding from the pick-up heads.

8. A materials-handling machine substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.