US2359674A - Press - Google Patents

Description

Oct. 3, 1944. R. T. POLLOCK PRESS 2 Sheets-Sheet 1 Filed Feb. 26, 1943 Jhven-Yvr ROBERT T. POL LOCK Oct. 3, 1944. R T, K 2,359,674

. PRESS I Filed Feb. 26, 1943 2 Sheets-Sheet 2 if; 3 HE- Patented Oct. 3, 1944 PRESS Robert T. Pollock, New York, N. Y., assignor to Maguire Industries, Incorporated, a. corpora tion of New York Application February 26, 1943, Serial No. 477,289

4 Claims.

My invention relates to a press, and more particularly a press wherein a plunger enters a die. The invention is especially useful in connection with an apparatus wherein loosely packed material is compressed. into a hard, firm cake, to which. use the invention is not restricted.

One object of the invention is to provide a press which will exert positive uncushioned force upon a substance to be pressed. Another object is the provision of a press, of the class described, wherein air will be released as the punch enters th die and compresses the material therein. A further object is to provide such a press which will permit release of such air without loss of material from the die. Other objects will be ap arent upon consideration of the present speciflcation.

The invention is shown by way of illustration in its embodiment in a press for forming foodstuffs into cakes in the accompanying drawings, wherein- Figure 1 is a perspective view of a press cnstructed in accordance with the invention;

Figure 2 is a vertical section through the die illustrated in Figure 1, showing in elevation the plungers and the compressed material therein;

Figure 3 is a vertical half mid section through the die, the'plungers and the compressed material illustrated in Fig. 2;

Figure 4 is a horizontal cross section taken on the line IV-IV of Fig. 2;

Figure 5 is an end view of the compression face of one of the plunger-s;

Figure 6 is a vertical section similar to Fig. 2, illustrating another form of the plungers; and

Figure 7 is a cross section of the upper plunger illustrated in Fig. *6, taken on the line VII--VII of Fig. 6.

In pressing material in a die, difficulty is frequently experienced because of air which is entrapped as th plunger enters the die. Air so entrapped maycushion the pressure of the plunger, preventing proper action upon the material, which is necessary to form a smooth surface and a uniformly compacted block. Furthermore, such entrapped air may cause a rebound of the plunger, which is particularly undesirable in certain types of press. Finally, in pressing loosely packed material, such as certain foodstuffs, into a compact cake, the cake may actually disintegrate when the pressure is released.

In the past, attempts have been made to overcome this difliculty by forming orifices in the walls of the die or in the compression face of the plunger, but such orifices necessarily become the bed plate ill, as will clogged or filled with the substance under compression, and continuously repeated pressing operations must be periodically halted in order to clean these orifices. Furthermore, such orifices in the forming surfaces of a press tend to mar the smooth firm face which is so desirable on the pressed cake.

The present invention provides a press wherein entrapped air may leave the die in suiiicient quantities to eliminate the above-mentioned difficulties, and wherein a substantially uniform, solid cake, with smooth, firm faces, may be produced.

In the drawings there is shown a press comprising a bed plate Ill, and a die ll positioned with its upper surface flush with the upper surface of said bed plate. A pair of plungers are movable in said die with the usual small clearances between their sides and the inner walls of the die. In order to facilitate escape of air from the die during the pressing operation the plungers are formed in a manner later to be described.

The upper plunger here shown is a punch II, which may be moved into and out of the die II, by means of an upper ram I 3 actuated by any known or convenient press mechanism. The lower plunger is illustrated as a bunter I, reciprocable within the die and carried by a lower ram i5, which is operated by known press mechanism. As here shown, the lower ram is operated by a forked lever It the end of which rests upon a stop I! when the bunter is in its lowermost position. The lever i8 periodically lifts the bunter until its upper face lies in the plane of be hereinafter more fully described.

The material to be pressedas descrete elements of foodstuff-is placed in a hopper i8 which is carried by the press above the bed plate iii. The hopper l8 terminates in an annular neck I! at its lower end. Immediately beneath the neck I9, is a feeder 20 which rests upon the bed plate l0 and is pivoted thereto concentrically with the axis of the neck It. The feeder comprises a central support 2i, from the base of which three angularly disposed radial arms 22, 23, 24 extend along the bed plate It], upon which they rest. The feeder 20 is thus pivoted, immediately beneath the hopper l8, to the bed plate i0, upon which it is supported in a state of equilibrium in all positions. The radial arm 22 acts merely as a support for the feeder. The arm 23 acts as a suppo t and also has pivoted to its outer end, in well known manner, the end of an actuating rod 25. A conduit 26 is carried .plane of the bed plate.

by the central support 2| and the radial arm 24. The conduit 26 passes through the radial arm 24 to form a lower opening which is normally closed by the bed plate lllupon which the arm 24 rests.- This lower opening is preferably larger than the opening in the die II. The upper end of the conduit 26 is fitted to the neck IQ for turning thereabout.

Thus, the hopper l8 being filled with foodstuff, the conduit 26 is immediately also filled thereby, contact of the lower end of the conduit against the bed plate l preventing the flow of foodstuff therefrom.

The die ll being filled with the foodstuff, and

the bunter 14 being in its lowermost position with the forked lever l6 resting upon the stop ll, the press is started. The upper ram l3 presses the punch l2 into the die thereby compressing the loose foodstuff therein into a solid, compact cake. As the punch is withdrawn, the bunter is raised by the forked lever l6 until its upper face lies flush with the upper face of the die II in the Thereupon, the compressed cake is positioned above the die and the bed plate. Tension is now applied by the press to the actuating rod 25, thereby turning the feeder 20 about its pivot in a clockwise direction, as seen in Figure 1. Thus the leading edge of the arm 24 pushes the formed cake off the top of the hunter and away from the die. As the lower end of the conduit 26 is positioned over the top of the die H, the die is filled with foodstuff from the conduit. Compression is now applied by the press to the actuating rod 25, the feeder returns to the position illustrated in Figure 1, and the cycle is repeated.

If the plungers are of usual construction air will be compressed between them during the pressing operation with the results noted above. Furthermore, the press must then be operated at a slow rate of speed if anything approaching satisfactory results are to be attained in pressing loosely packed or porous material. By reducing the cross section of the plungers back of their operating end faces, it is possible to facilitate'escape of air from the die during the forming operation.

As illustrated in Figs. 2 and 3, each side face 21 of the punch 12 has a depression 28 formed therein. The depressions 28 preferably extend into close proximity to the operating end face 29 of the punch, where the full section is provided. In the embodiment illustrated in Figs. 1 to 5, inclusive, only the longitudinal edges and the extreme front and rear portions of the punch are r not cut away. Similarly, the hunter M has a depression 30 formed in each of its side faces. Like depressions 28 in the side faces of the punch,

the depressions 30 preferably extend into close proximity to the operating end face of the hunter.

Without limiting the invention to any particular dimensions or proportions, it may be stated that in one successfully operated embodiment the die. Furthermore, the depressions extended to within twenty-five thousandths of an inch of the operating end face of each plunger. Manifestly other dimensions and proportions might be used-as, indeed, they have been, with complete success. In general the plunger or punch is always of full cross section immediately back of its operating end face for a distance of less than half of the smallest dimension of its operating end face, and is of reduced section back of this full section.

It is preferred to dish the operating end faces of the plunger, as is best shown at 3| and 32 in Fig. 3, in order to form ,beveled faces on the pressed cake.

Finally, the depression in each side face of the plunger need not consist of a single reduction in section as illustrated in Figs. 1 to 4, but may comprise a series of longitudinal flutes. Figs. 6 and '7 illustrate such a construction wherein the flutes 33 extend into close proximity to the operating end face of each plunger, as do the continuous depressions previously described.

By providing the usual clearances between the die and the plunger at the operating and face thereof, material in the die may be formed without loss in the usual way. At the same time, by providing a comparatively unrestricted air passage extending away from the point of compression from close proximity to the operating end face of the plunger, escape of air from the die is facilitated.

The forms of the invention herein described and illustrated in the accompanying drawings are presented merely by way of illustration. Other forms of the invention will readily suggest themselves to those dealing with such problems, which do not depart from the invention or the proper scope of the appended claims.

40 I claim:

clearance between the full section of the plunger and the die was twenty-five ten-thousandths of an inch, and the depressions in the side faces of the plunger provided a clearance of nine-hundredths of an inch between the plunger and the 1. A press comprising a die, a plunger movable in said die to form material therein, and means for operating said plunger, said plunger having a depression in a side face thereof extending to within a distance of the order of twenty-five thousandths of an inch back of its operating face to facilitate escape of air from said die during the forming operation.

2. A press comprising a die, a plunger movable in said die to form material therein, and means for operating said plunger, said plunger having a depression of the order of nine hundredths of an inch in a side face thereof extending to within a distance of the order of twenty-five thousandths of an inch back of its operating face to facilitate escape of air from said die during the forming operation.

3. For use with a press, a punch having a depression in each side face thereof extending to within a distance of the order of twenty-five thousandths of an inch from its operating end face.

4. For use with a press, a punch having a depression of the order of nine hundredths of an inch in a side face thereof extending to within a. distance of the order of twenty-five thousandths of an inch from its operating face.

ROBERT T. POLLOCK.

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