US3715796A

US3715796A - Fluid power eject mechanism for a powder compacting press and method of compacting

Info

Publication number: US3715796A
Application number: US00195515A
Authority: US
Inventors: G Detroyer
Original assignee: Wolverine Pentronix Inc
Current assignee: Wolverine Pentronix Inc
Priority date: 1971-11-03
Filing date: 1971-11-03
Publication date: 1973-02-13
Anticipated expiration: 1990-02-13

Abstract

A fluid power system for a pick-up and discharge mechanism for small manufactured articles or parts, such as made by a powder compacting press or the like. After compacting in a die cavity, the finished parts upon ejection from the die cavity or cavities are picked up by a pick-up head operatively connected to a suction source for displacement of the finished parts over a discharge port or ports through which the finished parts are individually discharged by means of a gentle blast of pressurized air. The suction forces to pick up the finished parts is obtained from a flow of air through an appropriate venturi-like aspirator assembly.

Description

States Patent 1 [111 3,715,796 eTroyer 1 Feb. 13, 1973 FLUID POWER EJECT MECHANISM [56] References Cited FOR A POWDER COMPACTING PRESS UNITED STATES PATENTS AND METHOD OF COMPACTING 2,689,492 9/1954 Ensign ..29/420.5

Inventor: Georges D. DeTroyer, Detroit,

Mich.

Assignee: Wolverine-Pentronix, Inc., Lincoln Park, Mich.

Filed: Nov. 3, 1971 Appl. No.: 195,515

Related U.S. Application Data Division of Ser. No. 861,611, Sept. 29, 1969, Pat. No. 3,645,658.

US. Cl. ..29/420, 29/208 E but. Cl ..B22f 3/02, B23p 19/04 Field of Search ..29/420.5, 208 E, 427, 430,

Primary ExaminerThomas H. Eager AttorneyRobert C. Hauke et al.

[5 7] ABSTRACT A fluid power system for a pick-up and discharge mechanism for small manufactured articles or parts, such as made by a powder compacting press or the like. After compacting in a die cavity, the finished parts upon ejection from the die cavity or cavities are picked up by a pick-up head operatively connected to a suction source for displacement of the finished parts over a discharge port or ports through which the finished parts are individually discharged by means of a gentle blast of pressurized air. The suction forces to pick up the finished parts is obtained from a flow of air through an appropriate venturi-like aspirator assembly.

6 Claims, 7 Drawing Figures 2a 2 i 8 0 6 a in 5555 I I Q Mim U EJECf-. DOWN PATENTEDFEB13 I975 3,715,796

SHEET 2 OF 3 FIGZ PATENTEUFEB 13 I975 SHEET 3 OF 3 FIG. 4

FLUID POWER EJECT MECHANISM FOR A POWDER COMPACTING PRESS AND METHOD OF COMPACTING REFERENCE TO RELATED APPLICATIONS This is a division of application, Ser. No. 861,611 filed Sept. 29, 1969, now US. Pat. No. 3,645,658, granted Feb. 29, 1972.

The present invention is related in part to US. Pat. Nos. 3,328,840, 3,328,842, 3,344,213, 3,414,940, 3,415,142, 3,561,054, 3,561,056, and 3,574,892 and to US. applications, Ser. No. 782,918 in the name of Joseph E. Smith for Multi-Tool Punch Set For Powder Compacting Press, and Ser. No. 785,584 in the name of Joseph E. Smith for Composite Punch for Powder Compacting Press, all of which are assigned to the Assignee of the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pick-up and discharge mechanism for presses and like machines and is of particular utility in automatic powder compacting presses. Powder compacting presses, as is known, are capable of manufacturing cores, beads and diverse articles of compacted powdered ferrite, glass or any other powdered material. In these presses or machines, the green compacted parts are generally relatively fragile and must be handled with caution during ejection, pick-up and transfer of the parts to the discharge station.

2. Description of the Prior Art In manufacturing machines, such as punch presses, powder compacting presses and the like which manufacture relatively small parts at a high rate of production, problems have been encountered in regard to the pick-up and discharge of the finished parts from the press for disposal in receptacles. For efficient operation of the machine, the finished parts must be discharged at the same rate that the press operates and in synchronism with the various work cycles of the press or other machines.

It has been the practice in powder compacting presses, for instance, to dispose a suction head over the die cavity or cavities after the last compacting stroke and then eject the finish compacted part or parts from the die cavities into the suction head where they are retained by means of a suction force for transfer to a discharge station at which point the suction force will be cut off causing the compacted parts to drop through respective discharge ports. This arrangement requires the provision of a suction source on the machine, such as a vacuum pump or the like, or an exterior suction source, which is not ordinarily available in a shop. This suction source then must be integrated into the operational cycle of the press such as to be effective at the proper time. Any malfunction of the suction system, which is not readily detected, will cause the finished parts to be damaged. As mentioned before, the green" compacted articles are relatively fragile and must be handled gently after ejection from the die cavity or cavities. For instance, if there is insufficient vacuum flow caused, for example, by clogged wire retaining screens within the pick-up head assembly, or for other reasons, the compacted parts ejected from the die cavities are being dragged rather than lifted to the discharge ports. When this occurs, the compacted parts can be easily broken as they approach the discharge ports. Another difficulty is caused when the vacuum flow is set too high, which allows the compacted parts to be dropped into the wrong discharge tube connected to each of the discharge ports by being swept across the die plate. Furthermore, any inadequate eject setting of the mechanism can prevent a proper pick-up of the O compacted parts, and instead the pick-up head strikes the compacted parts, thereby breaking them and causing loose particles and powder to accomulate on the die plate and within the separate discharge receptacles.

SUMMARY OF THE PRESENT INVENTION The present invention provides a novel fluid system for a pick-up head assembly of a work station positioner associated with a press or the like. The novel fluid system includes means replacing a separate source of vacuum and which is operated by a source of pressurized air readily available in the shop and adapted for a forced discharge of the compacted part or parts from the pick-up head. In the example of a powder compacting press in which the present invention may be embodied, after the work station positioner oscillates to the fill position and following the ejection of the compacted parts from the die cavities, the pick-up head assembly will be located over the discharge ports in the die plate. At this point, according to the present invention, the suction force is changed to air pressure to gently blow the parts through the discharge ports into their respective discharge tubes and into segregated containers. In conjunction with the exemplary powder compacting press, as disclosed in the aforementioned US. Patents and Patent applications, an appropriate rotary cam actuates a pilot valve to create a flow of air to the pick-up head assembly to blow the parts from the pick-up head assembly into the discharge ports. Previously, after ejection of the parts from the die cavities, the compacted parts are lifted into the pick-up head assembly by a continuous flow of air passing through an aspirator assembly, which causes the creation of a suction force or partial vacuum within the pick-up head assembly to thereby hold the compacted parts against a wire screen or any other perforated wall provided within the pick-up head assembly until the positioner moves to the fill position.

At that time, the pick-up head assembly is then located over the discharge ports and has carried the parts from the die cavities to the discharge ports. At this point, the source used to create the partial vacuum in the pick-up head assembly to retain the compacted parts within the pick-up head assembly is reversed by means of the actuation of a pilot valve to a flow of air pressure to gently blow the compacted parts from the pick-up head assembly through their respective discharge ports and from there into respective receptacles. By the provision of this arrangement and actuation thereof by the synchronized mechanism of the press or similar machine, the aforementioned disadvantages and difficulties of the prior art in picking up and discharging the finished parts from the machine, as described in the foregoing, are being primarily eliminated.

Further objects and additional advantages of the invention will become apparent from the following detailed description when read in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate a preferred embodiment of the invention as incorporated in an exemplary powder compacting press and in which:

FIG. I is a front view of an exemplary powder compacting press in which the improved pick-up and discharge system according to the present invention is embodied;

FIG. 2 is a cross section through the exemplary powder compacting press shown in FIG. 2 embodying the present invention as seen along line 22 thereof;

FIG. 3 is a top plan view of the exemplary powder compacting press shown in FIGS. 1 and 2 as seen along 7 line 3-3 in FIG. 2;

FIG. 4 is an enlarged cross section of the die plate and pick-up head assembly of the exemplary powder compacting press illustrating the suction cycle of the present invention as seen along line 4-4 in FIG. 3;

FIG. 5 is a similarly enlarged cross section through the die plate and pick-up head assembly of the exemplary powder compacting press illustrating the discharge cycle of the present invention;

FIG. 6 is a further enlarged fragmentary cross section through the aspirator assembly of the present novel fluid pick-up and discharge system of the present invention; and

FIG. 7 is a schematic fluid flow diagram schematically illustrating the operation of the present novel fluid pick-up and discharge system.

DESCRIPTION OF THE PREFERRED EMBODIMENT Although the particular press in which the improved fluid pick-up and discharge system of the present invention may be embodied forms no part of the invention herein disclosed, a brief summary of the construction and operation of an exemplary powder compacting press is given hereafter for the sake of description of the invention.

With reference to FIGS. 1-3, the exemplary powder compacting press 22, in which the invention may be of particular advantage, has a base 24 supporting a frame or housing 26 on which rests a work table 28. The frame or housing 26 encloses a drive mechanism 30 which, in this instance, comprises a camshaft 33 normally supporting a plurality of cam, three of which are shown in FIG. 2 at 23, 25 and 32, adapted to initiate the various work cycles of the press as is known. Camshaft 33 is normally driven by any conventional drive means (not shown) to permit the multiple cams to perform the various work operations of the press in timed sequence, as disclosed in the aforementioned US. Patents and applications, in which is additionally described a cam disposed so as to engage a treadle (not shown) which is centrally pivoted in the housing 26 for reciprocatory actuation of a ram member (not shown), so that upon rotation of this cam the ram is adapted to reciprocate a punch or punches 66 (FIG. 4) retained within a tool set (not shown), mounted in the work table 28 of the press 22. As further seen in FIG. 3, a die plate 42 usually integral with a punch retaining tool set is mounted within a recess 38 provided in the work table 28 and is suitably secured thereto by means of bolts 43, or the like, fitting into appropriate apertures provided in the die plate 42. The die plate 42, upon installation, is preferably flush with the surface of the work table 28.

Positioned on top of the work table 28 for horizontal, pivotal movement around a vertical axis in timed sequence as caused by actuation of the camshaft drive mechanism 30 of the press is a station positioner assembly 46 comprising an oscillating positioner arm 47 on the end of which are supported three work stations as follows: (a) a fill station to dispense powdered material into the die cavities through a dispenser head 48 which is supplied with powdered material by means of a flexible tube or conduit 4? from a powder material hopper 50, supported on the vertical station positioner axis and rotatable therewith; (b) a press station provided with anupper compacting member in the form of an anvil 52 which is adapted to be clamped down upon the die plate 42 by means of a pivotal clamp 54, FIGS. 1 and 2, supported on a shaft 61 and which is actuated by appropriate cam means (not shown). The clamp 54, as seen in FIG. 2, is provided with a pressure head 53 which is adjustable in relation to the anvil 52 by means of a micro screw adjustment 55; and (c) a pick-up station provided with a pick-up head 56 which, in the improved embodiment, is adapted to be selectively connected to a source of suction of air pressure by means of a common conduit 58 to retain the finished parts by suction above the die plate 42, after they have been ejected from the die cavities by the punches 66 (FIG. 4), and to discharge the finished parts from the pick-up head 56 for disposal of the finished parts through appropriate discharge apertures 64 (FIG. 5) into separate containers, as previously explained.

The dispenser head 48, the anvil 52 and the pick-up head 56 are all assembled on the station positioner arm 47 within appropriate recesses or apertures at the end of the oscillating positioner arm 47 of the station positioner 46. The anvil 52, which is positioned between the dispenser head 48 and pick-up head 56, is independently vertically movable relative to the latter so that upon forcing down of the clamp 54 on the anvil 52 the clamping force will not be transmitted to the adjacent dispenser head and pick-up head.

With reference to FIGS. 3-5, the die plate 42, as herein shown for example, is provided with a plurality of cavities 62, each defined by the bore of a die bushing 63 press fitted in appropriate apertures 65 within the die plate 42. The die cavities 62 are preferably arranged in the center of the die plate 42 in a geometrical pattern. The die plate 42 is further provided with a plurality of discharge apertures 64 corresponding in number to the number of die cavities 62. The discharge apertures 64 are located near the die cavities in order to reduce the angular movement of the positioner arm 47 to a minimum, and the center of each of the discharge apertures 64 is located parallel to an arc Y" extended from the center of the corresponding die cavities 62 described by the angular movement of the oscillating positioner arm 47. When the oscillating positioner arm 47 is angularly moved to a position placing the dispenser head 48 over the die cavities 62, the pick-up head 56 is positioned over the discharge apertures 64 and at the same time as the finished articles 74 are discharged through the discharge apertures 64 the die cavities 62 are again filled with powdered material for the next work cycle.

For illustrative purpose, the timed operation of the exemplary powder compacting press 22, as shown in FIGS. 1-3, is schematically as follows: after the machine is started, rotation of the camshaft 33 causes the cam 32 of the multiple cam drive mechanism 30 to act on a pivoted lever 70 which is suitably connected to a yoke 72 to thereby angularly rotate the oscillating positioner arm 47 of the station positioner 46 to position placing the dispenser head 48 over the die cavities 62 to fill each of the cavities with powdered material to a depth determined by the amount of withdrawal of each punch 66 within each die cavity 62. Hereafter, the

oscillating positioner arm 47 is caused to pivot around in timed relation to position the press station or anvil 52 over the die cavities 62, which position is illustrated in FIG. 3. In timed sequence, the pivotal anvil clamp 54 is actuated to pivot the clamp 54 around the clamp support shaft 61 to engage the clamp head 53 with the top of the anvil 52 so as to press the anvil 52 down upon the die plate 42 to completely cover the die cavities 62. Simultaneously, the punch or punches 66, shown in FIG. 4, within the die cavity or cavities 62 are advanced upwardly to compress the loosely dispensed powder within the die cavity between the head of the punch or punches and the bottom surface of the anvil 52. Thereafter, the oscillating positioner arm 47 is swung in timed sequence to a position placing the pick-up head 56 over the die cavities 62 to pick up the finished compacted parts 74 from each of the die cavities when they are ejected from the die cavities by a final advance of the punch or punches 66 through the die cavities, as illustrated in FIG. 4.

In accordance with the present invention, and'as particularly shown in FIGS. 4 and 5, the pick-up head assembly 56 comprises a cup 76 having one or more internal cavities 78 corresponding in number to the number of die cavities 62 for individual reception of each finish compacted part 74 from each of the die cavities after ejection therefrom by the final advance of the punch or punches 66, as shown in FIG. 4. Each of the pick-up head cavities 78 is connected to the improved fluid system by a conduit 58 and the upper portion of each cavity is closed off by a wire screen 80 or similar perforated means against which the ejected finish compacted part 74 is held in suspended position by a reverse air flow therethrough creating a partial vacuum or suction within the cavity 78, as illustrated in FIG. 4 by the direction of the arrows. To prevent too great a vacuum from being created in either of the pick-up head cavities 78, the cup 76 of the pick-up head assembly 56 provides a clearance between its lower edge 77 and the die plate 42 to permit a restricted flow of atmospheric air therethrough, as indicated by the direction of the arrows.

With reference to FIGS. 3-5, while holding the ejected compacted part 74 against the wire screen 80 within each of the cavities 78 of the pick-up head 56, the station positioner arm 47 is swung along the radius Y" to place the pick-up head 56 over the discharge ports 64 (FIG. 3). As shown in FIGS. 1 and 2, each of the discharge ports 64 is connected by a tube 82 to an individual container 84, such as a vial, bottle or the like, suitably supported within the housing 26 of the press 22 for easy access thereto so that it can be conveniently replaced when filled. When the positioner arm 47 has stopped its movement above the discharge ports 64, the partial vacuum or suction within the cavity 78 in the pick-up head 56 is converted to a gentle air flow permitting the parts 74 to be blown through their respective discharge port 64 and through a tube 82 into one of the containers 84. As shown, for example, in a multiple punch arrangement of the press, the die plate 42 is provided with a plurality of die cavities 62 corresponding in number to the number of discharge ports 64 (FIG. 3) arranged along the same geometrical pattern. The finish compacted part from each of the die cavities will be separately picked up in segregated cavities 78 provided in the pick-up head 56, disposed in the same geometrical pattern corresponding to the arrangement of the die cavities and the discharge ports, and will then be moved in that position to the discharge ports 64 to drop each part 74 into its respective discharge port corresponding to the position of its die cavity for disposal into a separate container 84. Thus, each container 84 always receives finish compacted ar ticles from the same die cavity to thereby provide a convenient inspection means. The containers 84 are numbered corresponding to the number of the die cavities so that it is easy to determine which die cavity produced inferior parts, requiring adjustment or renovation of the respective working parts. At the same time, the inferior parts produced in any one die cavity will be constantly kept separate, thereby eliminating a time consuming inspection procedure of the finished parts during any production run, as more in detail disclosed in the aforementioned United States Patents and Applications.

With particular reference to FIGS. 2 and 7, the improved pick-up and discharge system of the present invention comprises a conduit 86 which is connected to a source of air pressure (not shown) and extends into the press housing 26 for connection through a connector 88 to the inlet 90 of a pilot valve 94 positioned within the press housing 26.

As schematically shown in FIG. 7, the pilot valve 94 is a threeway valve of conventional construction having a first outlet 96 capsule of being controllably connected to or cut-off from the inlet 90 as a result of the operation of the pilot valve 94. The outlet 96 is connected by means of a tubing 98 to the inlet side of a first flow regulating valve 100 secured inside of the front panel of the housing 26. The valve 100 has an actuating stem 102 provided outwardly of the press housing with the control knob 104 by which the actuating stern 102 may be rotated to thereby adjust the fluid flow through the regulating valve 100. The outlet side of the first regulating valve 100 is connected by a conduit 106 to a T-connector 108 disposed in the upper rear portion of the press housing 26 underneath the press table 28. The upper branch 110 of the T-connector 108 extends through the press table for connection to the conduit 58 leading into the pick-up head 56 on the station positioner 46 to thus provide a direct fluid communication from the source of pressurized air (not shown) through the pilot valve 94 and through the tubing 98 into the first regulating valve 100 and from there through conduits 106 and T-connector 108 into the cavity or cavities 78 of the pick-up head 56 by means of the conduit nected constantly to the inlet 92 as shown schematically at 93 and by a tubing 112 to the inlet side of a second flow regulating valve 114, which is similarly secured to inside of the front panel of the housing 26 and has an actuating stem 116 provided outwardly of the press housing with a control knob 118 by which the actuating stem may be rotated to thereby adjust the fluid flow through the regulating valve. The outlet side of the second regulating valve 114 is connected by a conduit 120 through a check valve 122 to an aspirator assembly 124, shown in detail in FIG. 6. The through branch 126 of the aspirator assembly is in communication with an exhaust and filter assembly 128 secured outwardly to the rear of the press housing 26 to expel air from the system to the atmosphere. The upper branch 130 of the aspirator assembly 124 is connected to the lower branch 132 of the T-connector 108 and thereby, by means of the common conduit 58, to the pick-up head 56.

The first system including the first regulating valve 100 constitutes an air pressure system at a relatively low pressure rate, and the second system including the second regulating valve 114 constitutes a suction system in accordance with the present invention. With reference to FIG. 1, the fluid flow through the regulating

valves

100 and 114 is adjustable from a fully closed to a completely open position by means of manipulation of the control knobs 104 and 118, as indicated by the legends in FIG. 1. Under normal operating conditions of the press and under normal predetermined air pressure conditions, the control knobs 104 and 118 of the control valves will be set prior to the operation of the press approximately mid-way between the extreme open and closed positions, as indicated by the pointers in FIG. 1, to thus reduce or increase the air flow through the regulating valves as may become necessary by air pressure changes due to clogged filters or clogged screens 80 in the pick-up head 56 or for other reasons.

With particular reference to FIG. 6, the aspirator assembly 124 is provided with a body portion 134 generally resembling a conventional T-connector and having a through branch 126 and an upper branch 130. The through branch 126, which is connected to the exhaust and filter assembly 128, is provided with an axial bore 136 which, at the center of the body portion 134, communicates with a radial bore 138 extending through the upper branch 130 to provide fluid communication with the conduit 58 through the T-connector 108. The axial bore 136 converts within the body portion 134 into a coaxially aligned bore 140 of substantially smaller diameter than the bore 136 and into which is press-fitted a tube 142 which partly extends into the axial bore 136 a distance such as to end just short of the center of the axial bore 138 positioned normal thereto. The tube 142 is axially bored through, as seen at 144, to provide a restricted fluid communication from the conduit 120 and check valve 122 to the exhaust and filter assembly 128. The reduced fluid flow through the tube passage 144 provides a venturi 146 at the opening of the tube centrally within the body portion of the aspirator assembly 124.

Since the second system, including the inlet pipe 92 and second regulating valve 114, is constantly connected to the source of air pressure through the valve 94, a constant flow of air is being directed through the tubing 1211, check valve 122, and aspirator assembly 124 to the atmosphere through exhaust 128. The flow of air through the venturi 146 causes air to be drawn from the cavities 78 of the pick-up head 56, through conduit 58, T-connector 108 and through the aspirator assembly 124 out to the atmosphere. This constant reverse air flow or suction causes a partial vacuum, that is, the creation of an air pressure lower then atmospheric pressure, within the cavities 78 in the pickup head 56 by which, when the pick-up head is positioned over the die cavities 62 and the finish compacted parts 74 have been ejected from the die cavities by advancement of the punches 66, causes the parts '74 to be gently drawn up against the wire screen 80, as illustrated in FIG. 4. Due to the provision of the clearance between the bottom edge 77 of the pick-up cup 76 and the die plate 42, a restricted flow of atmospheric air is permitted to enter the cavities 78 at a rate less than the suction flow of air out of the cavities through conduit 58 which, however, is sufficient to prevent the creation of too great a vacuum within the cavities 78 by which the very fragile green compacted parts 74 may be damaged. The suction force is constantly maintained within the cavities as long as the first system remains disconnected from the source of pressurized air, and which will be activated only intermittently by timed actuation of the valve 94.

With reference to FIGS. 2 and 7, the pilot valve 94, which actuates the air pressure for discharge of the finished articles from the pick-up head 56 is provided with a spring-loaded valve operating plunger 148 supported for reciprocation in an extension 150 of the valve housing. Pivotally suspended above the plunger 148 and abutting against the upper end thereof is an actuating lever 152 which is rearwardly supported for pivotal rotation on a pivot pin 154, secured to the upper end of a support bracket 156, which is suitably attached to the top of the valve housing. The free end of the actuating lever 152 is provided with a cam follower roller 158 adapted to be constantly engaged in rolling contact against the circumferential surface 160 of the cam 23, which is fastened for rotation to the driveshaft 33 of the press 22. The spring-loaded valve plunger 14% normally tends to pivot the actuating lever 152 upwardly to thereby maintain contact with the cam surface 160, which has a lobe portion 162 for actuation of the valve plunger 1148 upon rotation of the cam 23. As mentioned previously, the valve 94 is preferably a three-way valve, as indicated in FIG. 7, which has a constantly open through-passage 93 providing open communication between the inlet and the outlet 97 for the suction system. The other portion of the valve 94 is provided with a variably openable and closable passage as determined by the position of the plunger 148. Normally the passage 95 is closed, as indicated by the position in solid line in FIG. '7, which, however, reverts to open position, shown in dotted lines in FIG. 7, to connect the inlet pipe 90 with the outlet 96 upon depression of the valve plunger 148 caused by the action of the cam lobe 162 thereon upon rotation of the cam 23.

The improved pick-up and discharge system functions as follows: considering the compacting press 22 being in operation and after the powder in the die cavity (or cavities) 62 has been compacted, as described previously, the station positioner arm 47 is swung towards the left, in the illustration in FIG. 3, by means of the synchronized cam drive mechanism 30 of the press to position the pick-up head 56 over the die cavity (or cavities) 62, which position is shown in FIG. 4. At this time and when the positioner movement stops, the punches 66 are advanced by a final stroke of the ram of the press to push the finished compacted parts 74 out of the die cavities into the cavities 78 of the pick-up head 56. This stage of operation is illustrated in FIG. 4.

As described above, pressurized air constantly flows through the regulating valve 114, conduit 120, through the check valve 122 and into the aspirator assembly 124. In the aspirator assembly, due to the suddently restricted flow through the tube passage 144, a considerably increased air flow velocity is created at the venturi opening 146 of the tube 142, which causes a purging action within the aspirator, thereby drawing air from the cavities 78 in the pick-up head 56 through the conduit 56 and T-connector 108 into the aspirator through the bore 138 and out through the bore 136 for exhaust to the atmosphere through the exhaust and filter assembly 128. This action causes the creation of a partial vacuum in the cavity (or cavities) 78 of the pick-up head 56 disposed over the die cavities 62 by which the finish compacted and ejected parts 74 from each of the die cavities is gently drawn upwardly against the wire screen 80 and retained thereon in suspended position as long as the suction air flow through the aspirator is maintained. Continuous rotation of the driveshaft 33 causes the station positioner arm 47 to be swung toward the right, in the illustration in FIG. 3, to dispose the pick-up head 56 over the discharge ports 64. During this movement of the station positioner arm, the flow of air through the suction system prevails thereby maintaining the creation of a partial vacuum in the pick-up head 56 to retain the finish compacted article or articles 74 against the wire screen 84) in the pick-up cavity or cavities 78 during transfer from the die cavities to the discharge ports 64. When the pick-up head 56 is positioned over the discharge ports, movement of the station positioner arm is 47 stopped.

By continuous rotation of the camshaft 30, the cam follower roller 158 of the valve 94 now starts riding up on the cam lobe 162 provided on the cam 23 thereby causing depression of the lever 152 to move the plunger 146 inwardly to open the passage 95 of the valve 44. At the time communication through the passage 95 is all the way open, pressurized air will flow through the regulating valve 100, and from there through the conduit 106, T-connector 108 and conduit 58 into the cavity or cavities of the pick-up head 56 to gently blow finished parts 74 from the cavities 78 through their respective discharge ports 64 and through a tube 62 into the respective container 84. This position is illustrated in FIG. 5.

As mentioned previously, the magnitude of the air pressure is relatively low so as to permit a gentle blowing-out of the compacted parts 74 to prevent them from being damaged in any way. However, the air pressure is sufficient to override the suction force created by the aspirator 124 without the necessity of disconnecting the air flow through the aspirator since the forced air pressure flow into the pick-up head cavities 78 is connected upstream of the aspirator thereby overcoming the suction effect and reversing the air flow within the conduit 58 to gently blow the parts 74 from the retaining screen into their respective discharge apertures 64. Due to the clearance provided between the bottom edge 77 of the pick-up cup 76 and the die plate 42, air is permitted to escape therethrough to the atmosphere to prevent the build-up of excessive air pressure within the pick-up head cavities 78 which could damage the fragile finish compacted parts 74. Back flow of air through the lower branch 132 of the T- connector 108 is prevented by the check valve 122, causing the air only to escape through the aspirator 124 and out to the atmosphere through the exhaust and filter assembly 128. It will be noted that the distance of the cam lobe 162 is relatively short, thus providing short blasts of gentle air pressure to blow the finish compacted parts out of the pick-up head 56. This operation coincides with the refilling of the die cavities with powdered material, since the filling head 48 (FIG. 3) of the station positioner during the blow-out operation will be positioned over the die cavities, as previously described. Continuous rotation of the driveshaft 33 causes the cam follower 158 to roll off at the other end of the cam lobe 162 to thereby again close the passage in the valve 94 and stop the supply of air pressure into the pick-up head 56. The flow of air through the suction system is continued to thereby resume partial vacating of air from the pick-up cavities 78, as described above.

It will be evident from the foregoing description that the present invention provides an improved pick-up and discharge fluid system for a powder compacting press or similar machine for positive blow-out of the finish compacted parts without causing the parts to be damaged. Additionally, the improved fluid system provides a continuous purging of the parts receiving cavities of the pick-up head and cleaning of the wire screens therein to prevent the wire screens from becoming clogged due to loose powder material or foreign substances.

The improved pick-up and discharge fluid system, as herein described, assures positive pick-up of the finish compacted parts and accurate disposal of the parts through their respective discharge ports and effectively prevents the relatively fragile compacted parts from being damaged during the pick-up, transfer and discharge phases of the operation.

Obviously, this improved system may be incorporated in a variety of similar high speed production machines capable of producing a multitude of relatively small, equal sized articles which have to be picked up, transferred and discharged from the machine in a timed cycle and where precaution is required for not damaging these articles.

The foregoing disclosure is only representative of a preferred form of the invention and is to be interpreted in an illustrative rather than a limiting sense, various modifications being contemplated as may be obviously resorted to by those skilled in the art without departing ill from the spirit and scope of the invention as hereinafter defined in the appended claims.

I claim:

1. In combination with a pick-up head assembly for transferring parts from an ejection station to a discharge station, first means causing an air flow in one direction for picking up said parts at said ejection station, second means causing an air flow in an opposite direction for discharging said parts at said discharge station, and means for displacing said pick-up head assembly from said ejection station to said discharge station, wherein said first and said second means comprise a source of air pressure, an aspirator connected between said source of air pressure and said pick-up head assembly and constantly open for *aflow of air therethrough to thereby cause said air flow in said one direction, a normally closed valve connected between said source of air pressure and said pick-up head assembly upstream of said aspirator to cause said air flow in said opposite direction when said valve is opened, and means for opening said valve in timed sequence with the displacement of said pick-up head assembly only when said pick-up head assembly is disposed at said discharge station.

2. The combination as defined in claim 1, in which said pick-up head assembly comprises at least one cavity, a conduit connecting said cavity with said aspirator to thereby cause the creation of a suction force within said conduit to suck said part into said cavity when said pick-up head assembly is at said ejection station.

3. The combination as defined in claim 2, further comprising conduit means connecting said cavity directly with said valve of said second means, said valve being normally closed but operable upon actuation to establish direct communication between said source of air pressure and said cavity to thereby force said part from said cavity when said pick-up head assembly is at said discharge station.

4. The combination as defined in claim 3, in which said pick-up head assembly is provided with means to permit a restricted flow of atmospheric air into said cavity when said air flow is in one direction to limit the amount of vacuum in said cavity and to permit a limited escape of air from said cavity to the atmosphere when said air flow is in the opposite direction to prevent an excessive pressure build-up within said cavity.

5. A method for making an article of predetermined dimension and density compacted from a powdered material by means of a die having at least one cavity and at least one reciprocable punch disposed within said cavity for reciprocation therein, said method comprising:

disposing a filling head associated with an oscillating station positioner over said die cavity, having a lower edge engaging the surface of said die; filling said die cavity with said powdered material; removing said filling head from over said die cavity and placing an upper compacting member over said die cavity for closing said die cavity; reciprocating said punch within said die cavity toward said upper compacting member for causing a predetermined compaction of powdered material in said die cavity so as to form a compacted artireiii ving said upper compacting member from said die cavity and placing a pick-up head assembly over said die cavity, said pick-up head assembly comprising a cavity provided with a perforated upper dividing wall, said cavity being connected to a source of fluid pressure;

reciprocating said punch through said die cavity for ejecting said compacted article from said die cavity into said pick-up head cavity;

constantly connecting said pick-up head cavity to a source of partial vacuum for thereby sucking said compacted article into said pick-up head cavity and against said perforated dividing wall to be retained thereagainst;

displacing said pick-up head assembly over a discharge port; and

momentarily connecting a second source of air pressure at a predetermined low pressure to said pickup head cavity to gently blow said compacted article from said pick-up head assembly through said discharge port.

6. A method for discharging a finished part from a machine having an ejection station and a discharge station, said method comprising:

disposing a pick-up head having a cavity over said ejection station;

ejecting said finished part from said machine into said cavity of said pick-up head;

creating a flow of air in said cavity of said pick-up head providing a suction force to retain said part therein;

moving said pick-up head from said ejection station to said discharge station; and

reversing said flow of air to gently blow said part out of said cavity of said pick-up head at said discharge station.

PEN-llZ-A-l UNITED STATES PATENT OFFICE CERTIFEQATE OF CGBRECTIGN Pa ent N 3,715,796 Dated February 13, 1973 Inventofls) GEORGES D. DETROYER error appears in the above-identified patent It is certif at t atcnt are hereby corrected as shown below:

ed th and that said L: P

, IN THE ABSTRACT Line 11, change "forces" to force IN SPECIFICATION Column 3, line 13, change "FIG. 2 to FIG. l

A line 51, change "cam" to cams Column 6 line 46, change "capsule" to capable Column line 12, A change "then" to than Column 9, line 50, after "arm" insert 47 after "is": cancel "47" Signed and sealed this 3rd dayof July 1973.

(SEAL) Attest':

EDWARD MJFLETCHERJR. Rene Tegtmeyer Attesting Officer Acting Commissioner of Patents l FORM PO-1059 (10- A USCOMM-DC 60376-P69 9 11.5. GOVERNMENT PRINTING OFFICE: 1959 0-355-334 PEN-ll2-Al UNTTED STATES PATENT OFFICE CERTIFIQ ITE 6F (IQRRECTIGN Patent No, 317151796 D t d February, 13, 1973 Inventor(s) GEORGES D. ROYER It is certif'ed ch t error appears in the above-identified patent and that said L: t

on; are hereby corrected as shown below:

v IN THE ABSTRACT Line 11, change "forces" to force IN THE. SPECIFICATION Column 3, line 13, change "FIG. 2" to FIG. 1

line 51, change "cam" to cams Column 6, line 46, change "capsule" to capable Column 8, line 12, I change "then" to than Column 9, line 5 0, after "arm" insert 47 after "is": cancel "47" Signed and sealed this 3rd day of July 1973.

(SEAL) Attest:

EDWARD M.'FLETCHER,JR. Rene Tegtmeyer Attestlng Officer Acting Commissioner of Patents USCOMM-DC 60376-P69 Q u.s. GOVERNMENT PRINTING OFFICE: 1959 o-:ea-::A

OFRM PO-lOSO (10-69)

Claims

1. In combination with a pick-up head assembly for transferring parts from an ejection station to a discharge station, first means causing an air flow in one direction for picking up said parts at said ejection station, second means causing an air flow in an opposite direction for discharging said parts at said discharge station, and means for displacing said pick-up head assembly from said ejection station to said discharge station, wherein said first and said second means comprise a source of air pressure, an aspirator connected between said source of air pressure and said pick-up head assembly and constantly open for a flow of air therethrough to thereby cause said air flow in said one direction, a normally closed valve connected between said source of air pressure and said pick-up head assembly upstream of said aspirator to cause said air flow in said opposite direction when said valve is opened, and means for opening said valve in timed sequence with the displacement of said pick-up head assembly only when said pick-up head assembly is disposed at said discharge station.

5. A method for making an article of predetermined dimension and density compacted from a powdered material by means of a die having at least one cavity and at least one reciprocable punch disposed within said cavity for reciprocation therein, said method comprising: disposing a filling head associated with an oscillating station positioner over said die cavity, having a lower edge engaging the surface of said die; filling said die cavity with said powdered material; removing said filling head from over said die cavity and placing an upper compacting member over said die cavity for closing said die cavity; reciprocating said punch within said die cavity toward said upper compacting member for causing a predetermined compaction of powdered material in said die cavity so as to form a compacted article; removing said upper compacting member from said die cavity and placing a pick-up head assembly over said die cavity, said pick-up head assembly comprising a cavity provided with a perforated upper dividing wall, said cavity being connected to a source of fluid pressure; reciprocating said punch through said die cavity for ejecting said compacted article from said die cavity into said pick-up head cavity; constantly connecting said pick-up head cavity to a source of partial vacuum for thereby sucking said compacted article into said pick-up head cavity and against said perforated dividing wall to be retained thereagainst; displacing said pick-up head assembly over a discharge port; and momentarily connecting a second source of air pressure at a predetermined low pressure to said pick-up head cavity to gently blow said compacted article from said pick-up head assembly through said discharge port.