US3330000A - Horizontal powder press - Google Patents

Description

July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Filed June 18, 1965 7 Sheets-Sheet 1 2 'PI LEFT RIGHT PUNCH 45% DROP PUNCH ANoDE' PRESSURE SIMULTANEOUS PREss|NG ANODE LENGTH p ofq I 2 L '3 LEFT f RIGHT PUNCH 63% DROP PUNCH \UNIFORM Q ANODE I W PREssURE ISIMULTANEOUS PRESSING I P P I ANODE LENGTH P NET EFFECT, P ANC 2' PRESSING P L 1 LEFT2 0 RIGHT PUNCH E PUNCH UNIFORM 2ND\ \IST PRESSING PRESSING .k SEQUENTIAL PRESSING z i of/NVE/WDRS 6 ea v/- e.%g ANGDE LENGTH 3p0 d2bZ6i5M-% dm(%ww=' ATTORNEYS July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS 7 Sneets-Sheet 2 Filed June 18, 1965 .4 rromvsgg.

July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Filed June 18, 1965 '7 Sneets-Sneet 3 l MATCH LIN E A TTORNEYS July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Filed June 18, 1965 7 Sneets-Sheec 4 I M ATC H MATCH A r TORNEYS July 11, 1967 c. E. LE ROY ET AL 3,330,000

' HORIZONTAL POWDER PRESS Filed June 18, 1965 '7 Sheets-Sheet 5 MATCH IN VEN TORS azz ame-CZ G. Zak/-24 Z Waczmzl "p wg wdai n Z 1 July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Fild June 18, 1965 7 Sheets-Sheet 6 635.25% erzeda MIMI f A TTOR/VEYS ly 1}], 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS 7 Sheets-Sheet '7 Filed June 18, 1965 ATTORNEYS dab? wk v3 1 v Crea$ i g7 59 M J42 flbacewm f -bkk fi United States Patent 3,330,000 HORIZONTAL POWDER PRESS Chester E. Le Roy, Waukegan, 11]., Benedict G. Barth,

Kenosha, Wis., and Edwin L. Macrowski, North Chicago, and Earl K. Takata, Arlington Heights, 111., assignors to Fansteel Metallurgical Corporation, a corporation of New York Filed June 18, 1965, Ser. No. 465,093 7 Claims. (Cl. 1816.5)

This invention relates to apparatus for fabricating pressed powder products and more particularly to a horizontal press for fabricating pressed powder electrodes of uniform density.

In post World War II years, an entirely new technology has emerged based on metals having extremely high melting point temperatures, the refractory metals. Because of their unique characteristics, the importance of these metals and the variety of uses to which they have been put has increased dramatically. However, inherent in their newfound utility are problems which create difliculties not encountered in the metallurgy of more familiar metals.

One major problem arises from the high melting point of such refractory metals including, for example, tungsten, tantalum, molybdenum, columbium, and others. Thus, many products which might otherwise be made by the usual metallurgical processes of melting, forging, casting, etc., have been developed by a nonanalogous technologypowder metallurgy. These products which have been produced from powder must often meet high standards not only of purity of the metal itself, but in consistency of their characteristics and in their performances. One such typical product is the tantalum capacitor in which the anode or positive terminal of the capacitor is made from tantalum powder. These anodes and similar devices are formed by pressing the tantalum powder under a high pressure and then sintering the powder so that the individual particles will form a bond with each other.

The use of such tantalum capacitors has increased because of tantalums high performance over wide ranges of tempeartures to which these capacitors are subjected. Thus, capacitors with tantalum electrodes are often utilized in space and other highly sensitive areas in which the characteristics of the components cannot vary one from the other, nor under the varying atmospheric and environmnetal characteristics to which they are subjected.

One of the major problems in the production of such products is that the variations in the density of the pressed anode cause variations in the electrical characteristics of the capacitors in which they are utilized. In fact, lack of uniformity in density of these anodes, if not controlled, may result in a substantial rejection rate of the capacitors because of their inability to perform up to the high standards required of them.

While, for the sake of simplicity, the following description in regard to the present invention will be directed toward an apparatus for the production of pressed tantalum electrodes, it should be understood that the apparatus embodying the present invention may be utilized to compact or press other powder to produce other desired products.

Although theoretically desirable, practically it is not possible to produce pressed powder electrodes which have absolute uniform density throughout their entire length and thickness. Any increase, however, in the uniformity of the density of pressed powder electrodes is, of course, valuable and does result in a substantially improved electrode.

Existing devices, in which powder is pressed along a generally vertical axis, have certain characteristics which inherently reduce the uniformity of electrode density. Thus, in such devices, the powder, by its own weight,

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presses against the lower end of the die, thereby causing increased density at one end of the electrode. In the production of electrodes, powder is often pressed around a wire which is used as a lead or electrical connection thereto. In existing devices, in which a wire is inserted from above the powder into the powder fill, the wire acts to compress or precompact the powder fill in its path as it is inserted. In those devices in which the wire extends up from the bottom of the die cavity, the powder tends to pass around the wire into the wire feed aperture which makes it difiicult to allow for a continuous feed of wire.

In accordance with the present invention, however, there is provided a device which is capable of increasing the uniformity of the density of pressed metallic powder electrodes. This device differs from existing apparatus primarily in that it operates along a substantially horizontal plane and, furthermore, provides pressing in synchronized and successive steps.

Pressing along a horizontal plane allows for increased unifonnity in the product since, in contrast to vertical pressing, the powder, by its own weight, does not tend to compact towards one end of the electrode. Furthermore, a horizontal oriented device may provide a chamber in which loose powder can be positioned completely around the wire prior to pressing without prepressing the powder. The horizontal orientation also facilitates continuous wire feed, selection and control of anode lead length and automatic operation of the press.

By'the present invention, modification in the pressing operation, facilitated by the horizontal orientation of the press, further provides for increased uniformity in the density of the pressed powder electrodes. This modification contemplates sequential pressing from either end of the pressing cavity. Under existing procedures of pressing the powder from one end against a stationary backup member, the density of the compact varies as a function of the electrode length and is substantially less at the end adjacent the stationary member than at the end adjacent the pressing member. Pressing simultaneously at both ends does not correct this deficiency but merely creates, in effect, two shorter electrodes having a stationary point of minimum density somewhere between the electrode.

ends.

This phenomenon results from normal frictional forces within the pressing cavity. Thus, as a result of pressure applied to one end only of powder, the powder is initially compacted and grain are moved toward the stationary member from the end of the pressing member. However, the walls of the cavity cause a certain amount of frictional drag, therefore, the force applied to any segment of 'the powder decreases as distance from the pressing element increases. Thus, when pressing only from one end, the powder at the opposite end is not moved at all and has a minimal amount of pressure applied to it. At that point, therefore, the electrode is least dense.

In simultaneous pressing from both ends a similar phenomenon occurs, the difference being only that the stationary plane or unmoved powder is located somewhere between the ends of the powder. Thus, at a given point, depending upon the relative pressures applied to either end of the powder, a fixed plane could be inserted into the powder without disturbing the pressing forces from either end. At this point, the density of the electrode is lowest, and if the distance from this point to the end of the electrode were the same as .the total length of an electrode being pressed from only one end, both electrodes would have substantially the same density characteristics.

However, if all the powder could be shifted in one direction or the other, the density of the overall electrode at any given point would be greater than the density of an electrode formed by either the one-ended or two-ended simultaneous pressing methods. The horizontal press incorporating the features of the present invention pro- 7 vides such a staggered pressing operation.

end of the electrode, thereby increasing the overall uniformity of the pressed electrode.

More specifically, the present invention incorporates a horizontal bore having a pressing cavity at one end. A selected amount of powder is fed into the bore normally at a point adjacent to and aligned with the pressing cavity.

Pressing of the powder within the pressing cavity is accomplished by two pressing members, one located in the bore on one side of the cavity and the other located on the other side of the cavity. When the powder is to be pressed around a wire, the wire may conveniently be led into the cavity through one of the pressing members.

After the powder has been dispensed, one pressing member moves forward against the powder forcing it into the pressing cavity. Meanwhile the other member has moved into the cavity and is fixed there to act as a backup punch. The pressing member moves in against the powder for a given distance to compress the powder to a selected 'size and density. When this pressing has been completed and the pressing member is stopped, the backup punch is then jogged forward against the powder a preselected amount, which increasesthe overall density of'the electrode and improves the uniformity of the density across the entire length of the product.

The control of the backup member is synchronized to the action of the pressing member. The backup member may be supported externally of the bore in a support mounted in a pressure applying means. When the backup member is initially moved into the pressing cavity, pressure is continuously applied thereto even though it is prevented from movement into the cavity while the pressing member initially presses the powder. Conveniently, the backup member may then be moved into the cavity by releasing it from its first fixed position. allowing it to move forward under the sustained pressure applied thereto until it is again stopped at a predetermined point.

Once the aforementioned pressing action has been completed, the backup member is retracted from the cavity and the pressing member is then moved forward to eject the pressed electrode from within the cavity. If the electrode has been pressed around a wire, the wire may be driven further independently of the pressing member for a preselected lead length and severed to completely discharge the pressed electrode from the apparatus.

Thus, the present invention is capable ofproducing an improved pressed powder electrode or similar product having a more uniform density across its entire length than a previously possible. In accordance with the invention, this increased uniformity is provided by staggered pressing of the powder and, furthermore, such staggered pressing is more easily controlled and the general consistency of the product is increased by pressing the product along a horizontal plane. 7

Numerous other advantages and features of the pres ent invention will become readily apparent from the following detailed description of the invention and one embodiment thereof, from the claims, and from the accompanying drawings in which each and every detail shown is fully and completely disclosed as a part of this specification, in which like reference numerals refer to like parts, and in which: 7

FIGURES 1a, 1b, and 1c are plots of electrode pressure versus electrode length for various pressing actions;

FIGURE 2 shows the arrangement of FIGURES 3a, 3b, 3c, and 3d;

FIGURES 3a, 3b 3c, and 3d are, when arranged in accordance with FIGURE 2, a diagrammatic elevational V pressed is supplied to a powder fill chamber 18 adjacent view partially in section of the horizontal press incorporating features of the present invention;

FIGURE 4 is a vertical sectional view showing the powder dispenser and reservoir taken along the lines 44 of FIGURES 3c and 5; V

FIGURE 5 is a side sectional view of the dispenser taken along lines 55 of FIGURE 4;

FIGURE 6 is a plan view of the backup punch and its control mechanism partially broken away showing,

the portions disposed below the mechanism; and

FIGURE 7' is another plan view showing additional pressed simultaneously by unequal forces. FIGURE 10.

shows how the uniforfmity of electrode density is substan tially increased by staggered synchronized pressings In the disclosed embodiment, pressed electrodes are formed by pressing powder within a cavity 10 defined by a replaceable carbidedie 12 between two punches, a backup punch 14 and a pressing punch 16. The powder to be to the pressing cavity 10 by a powder dispensing mechanism 20 disposed above the chamber. v Referring to FIGURES 4 and 5, there is shown a reser- 'voir 22 disposed above the powder dispensing mechanism 20 which, in turn, is located above the filling chamber 18. The reservoir 22 is held in place bya bracket 24 which is mounted to the main powder dispensing housing 26. The powder reservoir 22 terminates at the upper end of a tapered aperture 28, the lower end of which com- 42 through approximately wherein the powder in' the compartment 30 is dumpedinto a powder trough 44 leading to the top of the powder fill chamber 18.

V The top of the powder fill chamber is defined by a reciprocallyslidable wedge 46 fastened to the lower end .of a wedge support piece 48. A slot 50 in wedge support piece 48 engages an eccentric 52 mounted on one end of a shaft 54 which is rotated by the dispensing rack 40 through pinion 55 while dispensing the powder. Thus, the powder fill chamber 18 is open to the trough 44 as the powder is being dumped into the trough and is closed as the powder dispensing compartment .30 is returned to its powder receiving position in the reservoir 22.

While one particular dispensing mechanism has been described, it is clear that any suitable mechanism'may be used with the press. incorporating the present invention, such as that disclosed by J. D. Winters et al., in Patent No. 2,820,577, entitled Powder Feed Mechanism. The only requirement is that thepowder dispensing me'cha nism be capable of supplying a preselected amount of powder at the proper time to the powder fill chamber 18.

.Referring to FIGURES 3a, 3b, 3c, and 3d, the pressing a V punch 16 is carried by a punch holder 56 supported 7 throughout the entire cycle of operation in a bushing communication with V 56, and pressing punch 16 in case the machine jams or when the pressing punch is to be removed, i.e., when the size of the punch is changed for production of various size electrodes.

A wire 70 about which the powder is pressed feeds into the cavity around a wire tensioning device 72, through a wire feed clamp 74 and electrode ejection clamp 66, a horizontal bore 76 formed in the punch holder extension 62, punch holder 56, and the punch itself. The wire tensioning device 72 includes a tension disc 78 around which the wire is wound and which is attached to a shaft 80 rotatably supported in a bushing 82 slidably mounted on a straightener support plate 84 which is fixed to the main frame 60. The shaft 80 and bushing 82 slide within a guide plate 86 and tension on the disc 78 is maintained by a spring 88 connected between the slidable bushing 82 and the end of the support plate 84.

The housing 89 of the wire feed clamp 74 is afiixed to a feed clamp slide block 90 which is bolted by suitable bolts 92 to a yoke 94, the other end of which is connected to one end of a spring biased rod 96. The wire 70 is kept under constant tension to insure a more uniform wire lead length by a spring 98 acting between the end of the main frame 60 and a washer 100 fixed to the outer end of the rod 96 to bias a cam follower 102, bolted to the bottom of the wire feed clamp slide 90 against the surface of a wire feed cam 104 keyed to the main drive shaft 106 of the press. The main shaft 106 is supported by pillow block 107 fixed to the frame 60. One end of the slide block 90 is fitted with a hardened stop 108 which is designed to contact the end of an adjustable stop screw 110 to limit retraction of the feed clamp 74 and thereby control the lead length inside of the anode.

The wire feed clamp housing 89 is provided at either side with apertures 112 through which the wire 70 passes from the wire tensioning device 72 to the cavity 10. A fixed wire clamping jaw 114 is disposed within the housing 89 and below the level of Wire housing apertures 112. A dowel pin 116 connects a movable jaw 118 disposed above the apertures to a piston 120 which is raised and lowered by a compressed air cylinder 122 supported above the housing by a bracket 124 and clamp 126. The cylinder 122 is selectively actuated in any suitable manner, such as by a limit switch 128 energized by a limit switch cam 130 fixed to the main drive shaft 106.

Another clamping assembly, the electrode ejection clamp 66, is disposed between the wire feed clamp 74 and the powder dispensing mechanism 20. This clamp, of a similar structure to the wire feed clamp, is also provided with apertures 132 in its housing 64 through which the wire 70 passes. A wire support tube 134 which prevents buckling of the wire extends through one of the apertures 132 in the housing 64 of the electrode ejection clamp 66. Similarly to the wire feed clamp 74, the electrode ejection clamp 66 is provided with a lower fixed clamping jaw 136 and an upper movable jaw 138 reciprocated by a piston 139 attached thereto through a dowel pin 140. The piston 139 is driven by an air cylinder 142 supported on top of the housing 64 by a suitable bracket 144 and clamp 146.

, The, electrode ejection clamp housing 64 is bolted to a slide block 148 to which a cam follower 150 is attached by a suitable nut and bolt assembly 152. The cam follower 150 rides in the track of the electrode ejection cam 154 keyed to the main drive shaft 106 which causes reciprocal movement of the clamp 66. As explained above, the pressing punch 16, punch holder 56 and punch holder extension 62 are mounted on one side of the electrode ejection clamp housing 64. The cylinder 142 of the electrode ejection clamp is selectively actuated by a limit switch 156 which is suitably energized, e.g., by another cam 158 similar to the wire feed clamp switch energizing cam 130.

As indicated above, the apparatus is provided with a second pressing member, the backup punch 14 which is mounted in a backup punch support 160 that is supported as it reciprocates to and from the cavity 10 in a fixed bearing block 162. The backup punch support 160 is attached to the piston 164 of a compressed air backup punch control cylinder 166 attached to a backup slide 168 by suitable fastening bolts 170. A cam follower 172 is attached to the backup slide 168 by a suitable nut and bolt assembly 174 and rides in the track of a backup cam 176 keyed to the main drive shaft 106.

Referring now also to FIGURES 6 and 7, there is shown threaded to the backup punch piston an adjustable stop ring 178 which is designed to engage a stop lever 180 attached to a stop lever mounting plate 182 disposed below the piston 164. As the air cylinder 166 continues to move forward toward the cavity 10 under control of the backup punch cam 176, it carries the piston 164, support 160 and punch 14 forward until the ring 178 engages the stop lever 180. The cylinder 166 continues forward, and applies pressure to the piston 164 to fix the backup punch 14, which at this point is located within the pressing cavity 10, in place with the ring 178 hard against the lever 180. As the cylinder 166 continues to move forward, an actuating rod 184 mounted on the cylinder 166 engages a stop lever release latch 186 to release the stop lever 180 and allow the piston 164 to move forward under air pressure until the stop ring 178 engages a fixed stop 188 located below the stop lever 180.

Retraction of the backup piston 164, backup punch support 160 and backup punch 14 is provided by mechanically connecting the piston 164 to the cylinder 166. A catch rod 1919, supported on the adjustable stop ring 178, extends back parallel to and above the latch release actuating rod 184 and through a retracting catch supporting member 192 mounted on the cylinder 166. A spring loaded retracting catch 194 slides along the outer diameter of the catch rod and over a catch ring 196 fixed to the extremity thereof as the cylinder 166 moves forward as previously described. At the point where the actuating rod 184 releases the stop release lever 180, the spring loaded retracting catch 194 engages the catch ring 196 so that when the backup cam 176 causes the cylinder 166 to retract, the piston 164 is mechanically coupled thereto as shown in FIGURE 6 and is immediately retracted therewith. As the cylinder 166 returns to its completely retracted position, a release screw 198 in line with the extension on the retracting catch 194 engages it to release the catch ring 196, thereby allowing for repetition of the cycle.

In operation, at about the time a cycle is completed, the electrode ejection punch cam 154 starts retracting the electrode ejection clamp 66 and the pressing punch 16 attached thereto. At about this time, the powder dispensing mechanism 20 operates as previously described to dispense powder into the powder receiving chamber 18 simultaneously lifting the chamber cover or wedge 46 so that the powder falls into the chamber. When the clamp 66 has positioned the pressing punch 16 immediately adjacent the chamber 18, the associated switch cam 158 de-energizes the ejection clamp 66 releasing the wire 70 just after the wire feed clamp cam 130 activates its limit switch 128 to cause the feed clamp 74 to grip the wire 70. The wire feed clamp 74 then retracts under pressure of the biasing spring 98 until the hardened stop 108 located in the wire feed clamp slide block 98 engages the adjustable anode lead length screw 110.

At this point, the electrode ejection clamp 66 is reenergized clamping the wire 70 and the wire feed clamp 74 releases the wire. Simultaneously with this action, the backup feed cam 176 advances the cylinder 166 and piston 164 until the adjustable stop ring 178 engages the stop lever 18!) at which point the leading edge of the backup punch 14 is disposed within the pressing cavity 10. The cam 176 continues to advance the cylinder 166,

thereby keeping pressure on the piston 164 and the backup punch support 160, so that the punch 14 remains absolutely stationary within the cavity 10. By this time, the powder dispensing operation is completed and the power fill chamber covering wedge 46 has returned to cover and completely enclose the powder fill chamber 18.

The pressing operation is now commenced by advancing the pressing punch '16 and wire 70 through the chamber 18 and into the pressing cavity pushing the powder in front of it. This is accomplished by the electrode ejection cam 154 advancing the associated. clamp '66 which, because it is energized, maintains the wire 70 fixed relative to the punch 16. This action continues for a predetermined distance until the pressing stroke is completed.

As'the electrode ejection cam 1'54 brings the clamp and punch to a halt, the air cylinder 166, which has advanced under control of the backup punch cam 176, reaches the point where the actuating rod 184 engages the stop lever release latch 186 thereby disengaging the lever 180 from engagement with the adjustable stop ring 1 78. Due to the high air pressure that has built up on the back of the piston 164, the backup punch 14 is driven a short distance into the cavity 1% to provide the secondary reverse pressing action until the stop ring 178 drives the stop lever 180 against the fixed stop 18S disposed below the lever. Immediately after this pressing stroke, the backup cam 176 retracts the cylinder 166 which, as explained above, having engaged the piston 164 mechanically via the catch 194, catch ring 196 and rod 190, withdraws the backup punch 14 from within the pressing cavity 10. 7

When the backup punch 14 has been retracted, the electrode ejection clamp cam 154 again advances the clamp 66 driving the pressed electrode out of the cavity 10 until it is held only by the wire 70 over a conveyor belt 260 which carries the ejected electrodes away from the apparatus. The wire feed clamp 74 is now re-energized and the electrode ejection clamp 66 is de-energized. The wire feed clamp 74 is then advanced by the feed clamp cam 104 which, since it is clamped to the wire 70,

further ejects the electrode from the machine so a cutting 'mechanism (not shown) of anysuita'b-le type can be activated to cut the wire 70 and disengage the electrode from the machine. The clamps 66, 74 are then retracted as aforementioned and the cycle is repeated.

Thus, there has been shown and described a new and novel device for pressing products from metallic powder or any other similar substance. The press is capable of functioning automatically and continuously providing a constant feedof wire so the electrode may be. pressed therearound to form a lead integral therewith.

Furthermore, the disclosed press provides for increased uniformity of the compacted electrodes not only because of horizontal oriented pressing, but also because of its controlled, synchronized, staggered pressing operation. This allows for not only a higher uniformity in the density of the'pressed electrodes as a function of length of theelectrodes, but has provided for more'uniformity from product to product. 7

It will be readily observed from the fore-going detailed description of the invention and in the illustrated embodiment thereof that numerous variations and modifications may be effected without departing from the true spirit and scope of the novel concepts and principles of this invention.

What is claimed is:

pressure to said second pressing member, means for retaining said second pressing member stationary in one end of said die cavity while under pressure, means for advancing said first pressing member through said chamber topress powder in said cavity against said stationary second member, means for releasing said second mem-.

ber retaining means upon completion of pressing by.

said first pressing member, said second member upon release of said retaining means advancing in response to the pressure from said pressure applying means to fur-' ther press the powder in said cavity against said stationary first member, and means for ejecting the pressed prod uct from the apparatus. a

2. A powder press for producing uniform pressed powder products comprising in combination a die having.

a pressing cavity therein, a first punch disposed at one side of said cavity, said first punch adapted to have a wire pass there-through and extend therefrom, a backup punch disposed in the opposite side of said cavity, means 7 for advancing said first punch and wire into said cavity to press powder therein around said 'wire and against said backup punch, means synchronizedto cessation of.

nism for controlling movement of one'of said punches 7 comprising a punch support carried by an air cylinder;

means coupled to said cylinder for displacing said cylin der and said support towards the pressing cavity, stop means engaging said support for interrupting movement of said support and'pu-nch while the other punch is being operated, means attached to saidv cylinder for releasing said support stop means to allow for pres-sing displacement of said punch into the cavity, and catchmechanis'm responsive to the displacement of said support for me.- chanically connecting said supportand cylinder.

4. A press for producing an electrode from metallic powder comprising in combination means defining a horizontally disposed'hollow bore provided with a powder receiving chamber, means defining a pressing cavity adjacent to said chamber, a powder dispensing mecha-' nism disposed above said chamber, said dispensing mechanism operable to open the top of said chamber and provide a measured supply thereto of powder for pressing, said powder dispensing means operable to close said chamber upon completion of said supplying operation, a

1. Apparatus for forming a product pressed from powder comprising in combination means defining a-ho-rizonta'lly oriented bore'including a powder chamber, a pressing die provided with a cavity adjacent to and aligned with said bore, a dispensing mechanism for supplying powder to said chamber, a first powder pressing member disposed in said bore on one side of said chamber, a second powder pressing member, 'means for applying pressing punch disposed at one'end of said chamber opposite from said cavity, said pressing punch adapted to have a'wire pass therethrough and into said chamber, a backup punch mounted in one end of a support and piston, a. compressed air cylinder coupled to said piston, means displacing said cylinder towards the :said cavity, a stop lever engaging the support when said backup punch has entered the cavity to interrupt displacement thereof, a mechanism synchronized with the stopping of said backup punch for displacing said pressing punch through said chamber and into said cavity to compress said powder, lever release means on said cylinder synchronized with completion of said pressing punch displacement for engaging said stop lever to release said support, said cylinder driving saidbackup punch under pressure against said partially compressed powder to complete compression thereof from the end opposite to that'pressed by said pressing punch, a catch connecting said backup punch with said cylinder upon completion of said backup pres-sing to allow for positive withdrawal of said punch on retraction, of said cylinder, and means displacing said 'wire to eject said pressed product from said cavity.

5. Apparatus for forming a compacted product from powder including in combination means defining a cavity in which the powder is pressed, dispensing means for supplying powder, a pair of powder pressing members,

means for advancing one of said members into said cavity to press powder therein against the other of said members, and mechanism for controlling movement of said other member comprising means for applying pressure to said other member to advance it into said cavity, means for interrupting the advance of said other member while said one member is advancing into said cavity, fixed stop means, and means releasing said interrupting means when said one member has advanced into said cavity whereby said pressure applying means causes said other member to spring into said cavity to further press said powder until engaged by said fixed stop means.

6. A mechanism for controlling action of a powder pressing member comprising a support afiixed to said member, means coupled to said support for applying pressure thereto, means connected to said pressure applying means for advancing said pressure means, support and pressing member towards a powder pressing cavity, a stop lever engaging said support to interrupt its movement towards the cavity, a stop lever release attached to said pressure applying means for releasing said support stop lever as said pressure means is advanced, a fixed stop for limiting amount of movement of said support and said member when said stop lever is released, a catch for connecting said support to said pressure applying means when said support contacts said fixed stop, and means for retracting said pressure means and said support and member connected thereto.

7. A horizontal press for production of pressed powder electrodes including in combination means defining a horizontally disposed bore provided at one end with a powder receiving chamber, an interchangeable die positioned at one end of said bore and defining a pressing cavity aligned with said chamber, a powder supply reseivoir disposed above said chamber, powder dispensing mechanism for communication between said reservoir and said chamber, said powder dispensing mechanism including a rotatable metered compartment for measuring the amount of powder to be dispensed and for dumping the powder therein into a chute communicating with said chamber, a reciprocable wedge forming part of the wall of said chamber, and means for alternately rotating said compartment and raising said wedge whereby powder dumped into said chute falls into said chamber and for returning said dispenser and wedge to their original positions whereby said compartment communicates with said reservoir and said wedge closes said chamber, a powder pressing punch disposed in said bore adjacent to said chamber, said pressing punch adapted to have a Wire pass therethrough and into said chamber, a horizontally oriented compressed air cylinder, a support piston carried by said cylinder, a backup punch supported in said support piston external to said die and aligned with said cylinder, means connected to said cylinder for advancing it towards said cavity whereby said piston and backup punch are also advanced, a stop lever engaging said piston to interrupt its movement when said backup punch is in said cavity whereby continued advance of said cylinder increases the pressure on said piston, means synchronized to the interruption of said backup punch movement for advancing said pressing punch and wire through said chamber and into said cavity to press the powder in said cavity around said wire and against said backup punch, a fixed stop, a stop lever release mounted on said cylinder and synchronized with completion of pressing punch movement for releasing said stop lever whereby pressure on said piston causes said backup punch to spring into said cavity until said piston engages said fixed stop, a retracting catch for mechanically connecting said piston to said cylinder when said piston has engaged said fixed stop, said cylinder advancing means synchronized to said fixed stop engaging said piston for retracting said cylinder whereby said backup punch is withdrawn from said cavity, and means synchronized with removal of said backup punch for advancing said pressing punch and wire together and for subsequently advancing only said wire whereby said pressed powder electrode is ejected from said cavity.

References Cited UNITED STATES PATENTS 1,638,002 8/1927 Lynn 18-36 XR 2,384,163 9/1945 lFlowers 18-16.5 2,762,078 9/1956 Haller 18-16.5 2,777,162 1/1957 Banzhof 18-16.5 2,798,255 7/ 1957 Winters.

2,821,748 2/1958 Willi 18-16.7 3,149,375 9/1964 Gehl 18-36 XR 3,189,947 6 1965 Pettkoske 18-36 3,192,561 7/1965 Archer et al. 18-5 3,257,709 6/1966 Fernan et al. 18-36 XR WILLIAM J. STEPHENSON, Primary Examiner. J. HOWARD FLINT, JR., Examiner.

Claims (1)

1. APPARATUS FOR FORMING A PRODUCT PRESSED FROM POWDER COMPRISING IN COMBINATION MEANS DEFINING A HORIZONTALLY ORIENTED BORE INCLUDING A POWDER CHAMBER, A PRESSING DIE PROVIDED WITH A CAVITY ADJACENT TO AND ALIGNED WITH SAID BORE, A DISPENSING MECHANISM FOR SUPPLYING POWDER TO SAID CHAMBER, A FIRST POWDER PRESSING MEMBER DISPOSED IN SAID BORE ON ONE SIDE OF SAID CHAMBER, A SECOND POWDER PRESSING MEMBER, MEANS FOR APPLYING PRESSURE TO SAID SECOND PRESSING MEMBER, MEANS FOR RETAINING SAID SECOND PRESSING MEMBER STATIONARY IN ONE END OF SAID DIE CAVITY WHILE UNDER PRESSURE, MEANS FOR ADVANCING SAID FIRST PRESSING MEMBER THROUGH SAID CHAMBER TO PRESS POWDER IN SAID CAVITY AGAINST SAID STATIONARY SECOND MEMBER, MEANS FOR RELEASING SAID SECOND MEMBER RETAINING MEANS UPON COMPLETION OF PRESSING BY SAID FIRST PRESSING MEMBER, SAID SECOND MEMBER UPON RELEASE OF SAID RETAINING MEANS ADVANCING IN RESPONSE TO

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