US3887317A

US3887317A - Pressing apparatus

Info

Publication number: US3887317A
Application number: US476148A
Authority: US
Inventors: Werner Plocher; Horb Ihlingen; Franz Kuhl; Bernhard Huttermann
Original assignee: Jurid Werke GmbH
Current assignee: Federal Mogul Bremsbelag GmbH
Priority date: 1973-06-06
Filing date: 1974-06-03
Publication date: 1975-06-03
Anticipated expiration: 1992-06-03
Also published as: JPS5032573A; DE2328700B1; GB1420906A; DE2328700C2; FR2232384A1; FR2232384B1

Abstract

A pressing apparatus for the production of compacted bodies from different powdered materials which are filled layer by layer into a pressing die, is provided with a filling system comprising a plurality of filling frames or shoes which are movable by first driving means in a guideway laterally offset from the filling opening of the die, and by second driving means out of said guideway across the table of the apparatus to the filling opening and back to the guideway.

Description

United States Patent Plocher et al.

PRESSING APPARATUS lnventors: Werner Plocher; Horb Ihlingen;

Franz Kiihl, all of Herdecke', Bernhard Hiittermann, Glinde, all of Germany Assignees: Jurid Werke GmbH, Glinde;

Maschinenfabrik Lauffer & Butscher, Muhlen, both of Germany Filed: June 3, 1974 Appl. No.: 476,148

Foreign Application Priority Data June 6, 1973 Germany 2328700 US. Cl. .r 425/257; 425/78; 425/l 30 Int. Cl B30!) 11/02; B30b l5/3O Field of Search 425/78, 130, 256, 257,

[ June 3, 1975 [56] References Cited UNITED STATES PATENTS 2,208,054 7/l940 Reed 425/130 2,2l8,l96 10/[940 Hagor 425/l30 X 2,552,090 5/l95l Eusner 425/[30 X Primary ExaminerJ. Howard Flint, Jr. Attorney, Agent, or Firm-Young & Thompson [57] ABSTRACT 8 Claims, 9 Drawing Figures PATENTEDJUH3 1975 3,887,317

PRESSING APPARATUS BACKGROUND OF THE INVENTION The invention relates to apparatus for charging pressing dies with several layers of powder-like materials, particularly for the production of a multi-layer sinter compact, by employing a plurality of charging shoes adapted to be traversed on a table.

For the production of multi-layer sinter compacts the pressing dies must be charged with powder materials in consecutive layers. For this purpose the charging shoes which have been filled with the several materials must be consecutively traversed over the pressing die in the proper sequence, It is also necessary that the several substances should substantially not intermix during the charging operation.

There are frame type presses known in which the charging shoes are moved to the pressing dies from the back of the press, i.e., the side opposite that from which the press is controlled. If several charging shoes containing different materials are to be used the paths of the several charging shoes converge at angles which do not exceed 90. In the case of column presses charging shoes can also be advanced to the die opening from the left and right as well as from the back of the press.

Although arrangements of such a kind permitt the several substances that are to be filled into the pressing die to be kept satisfactorily separate they can be used only if the lip of the filling opening of the die is flush with the press table. Moreover, the spatial requirements of such arrangements are considerable.

Conventional multi-chambered charging shoes permit several materials to be introduced into pressing moulds although this can be done only in a predetermined and fixed consecutive order. Multi-chamber charging shoes are certainly suitable as such for charging dies having openings with edges or upper surfaces not contained in a plane but in a concave or convex surface. However, it is impossible without an expenditure which is no longer acceptable in such cases to keep the substances that are to be charged separate when multiple chamber charging shoes are used, particularly not when the substances differ in specific gravity.

SUMMARY OF THE INVENTION A main object of the invention consists in providing apparatus requiring little space for charging pressing dies with several layers of different powders in such a way that the dies can be satisfactorily charged even when the upper surface of the charge in the die in cross section deviates from a straight line.

According to the invention a novel apparatus of the specified kind is provided with a guideway which is laterally offset from said filling opening, and with a plurality of charging shoes which are movable on said guideway, and of which each one can be coupled for traverse along said guideway to a first drive means and for traverse substantially perpendicularly thereto to a second drive means. Furthermore, it is also proposed to mount each charging shoe detachably on a baseplate in said guideway, said baseplate closing the bottom of the shoe in the guideway. According to yet another feature of the invention closing means are also provided for keeping the bottom of each charging shoe closed during its traverse by the second drive means to the edge of the filling opening.

In a preferred embodiment of the invention the baseplate can be coupled to the second drive means for traversing the charging shoe towards the filling opening substantially perpendicularly to the guideway.

In yet another desirable embodiment of the invention the tableis provided in the path of traverse of the charging shoe by the second drive means with a table top contour adapted to keep the bottom of the charging shoe closed during its traverse from the guideway to the filling opening, the shape of said contour corresponding to the non-linear cross section or non-linear shape of the edge of the filling opening.

In apparatus according to the invention the possible number of layers is limited substantially only by the availability of space for accommodating the necessary hoppers and charging shoes. The several substances can be kept cleanly separated because each substance is conveyed in a separate charging shoe. No commixture in the charging shoes can therefore occur because each charging shoe is itself charged only by a particular hopper with which the shoe is associated. Accordingly, inside the die cavity each layer will be cleanly deposited on the preceding layer. Without difficulty practically any kind of die used in practice can be filled, irrespectively as to whether the edge of the filling opening is concave or convex in any one direction on the top of the press table, because the pressing die can be so disposed that all the charging shoes are traversed into charging position along the same path. In the case of conventional dies in which the side walls are relatively perpendicular the direction of approach will be normal to the non-linear edge of the filling opening. This principle is also applicable to dies which in plan have the shape of a parallelogram, approach being at one of the parallelogram angles to the edge of the opening which is non-linear. Subject to slight additional aids for sealing the edges of the charging shoes it is also possible to charge dies which have an upper filling surface that defines part of the surface of a cone.

The principle which underlies the invention resides in slidably disposing the charging shoes in a row offset from the filling opening of the die and in then traversing the shoes out of the two into charging position at an angle which depends exclusively upon the shape of the die.

In the case of frame type presses the guideway for the charging shoes is preferably located at the rear of the press and the hoppers containing the several types of powder are preferably also disposed on that side but at a higher level.

The first drive means may consist of a chain travelling underneath the guideway and fitted with driving dogs adapted to engage abutment members attached to the baseplate and projecting downwards through a longitudinal slot in the guideway. Alternatively the baseplates may be detachably coupled together and the train of baseplates pushed or pulled in intermittent motion along the guideway by pulling or pushing means at one end of the train, one charging shoe at a time being thus advanced to a point where the second drive means is adapted to move this shoe out of its position in the line towards the filling opening and then back again into alignment with the rest of the train.

Other aspects and features of the invention will be understood from the claims and from the following detailed and particular description in connection with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a simplified part sectional representation of a column type press using a conventional charging shoe;

FIG. 2 is a view in plan of the die table of the column type press in FIG. 1, partly in section;

FIGS. 3 and 4 are representations of apparatus according to the invention analogous to the above representations of conventional equipment in FIGS. 1 and 2;

FIG. 5 is a perspective view of parts of apparatus according to the invention and a modified arrangement for traversing the charging shoes;

FIGS. 6 and 7 are end and side views of charging shoes used in apparatus according to FIG. 5; and

FIGS. 8 and 9 are a plan and elevational view of the means for cross traversing the charging shoes.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIGS. 1 and 2 these illustrate the state of the art in the case of a column type press containing a die plate 11 and columns 12. The press is equipped with a conventional two-chambered charging device comprising a hopper 13 containing two

chambers

14 and 15 with bottom pouring tubes 16 and 17 and a twochambered charging shoe 18 divided into an upper chamber 19 and a bottom chamber 20. These two

chambers

19 and 20 communicate through a drop flap 21 which can be opened to allow a powder to be also discharged from the upper chamber 19. In the drawing two layers A and B of powder materials for the production of a two-layer sinter compact have already been introduced into the open cavity of a pressing die between a bottom ram 22 and the wall of an opening 24 through the die table.

The directions in which traverse is possible are indicated by two-headed arrows in FIG. 2. The traversing paths pass between the columns 12 of the press from and to the right and the left as well as the back (at the bottom in FIG. 2). In the case of a filling which has an upper surface that rises above the die plate, as exemplified in FIG. 1 by the convexity of the layers A and B, only one of the three possible directions of movement is actually possible. In the case shown in FIGS. 1 and 2 this is from and to the back. If a conventional twochamber charging shoe isused, the difficulty which arises is that the layers of powder cannot be deposited in the die cavity so that they have a satisfactorily well defined interface. If more than two layers are needed. then these difficulties are further accentuated. Moreover, the operation of filling the charging shoe through the pouring tubes takes time to perform.

FIGS. 3 and 4 illustrate a column press equipped according to the present invention, comprising columns 30, a die table 32 containing the die cavity formed between the walls of an opening 34, a bottom punch 36 and an upper punch 38. For charging the die cavity with different powder materials in consecutive layers charging shoes 40 are used having a bottom face 42 which conforms with the contour of the top of the filling. The charging shoes 40 are movable in a guideway 50. For this purpose the charging shoes 40 are mounted on an arrangement 48 of baseplates formed with saddles 49 corresponding to the arches 42 for reliably closing the bottom of the charging shoes. The baseplate arrangement 48 may be either an integral part or it may be composed of a plurality of separate baseplates detachably connected together. In the embodiment shown in FIG. 4 the baseplate arrangement 48 and the charging shoe can be traversed in the guideway 50 in either direction by means of a hydraulic cylinder which has a piston rod 62 attached at its free end to the system of baseplates 48, as indicated in diagrammatic form in FIG. 4. The hydraulic cylinder 60 is doubleacting and is supplied with pressure fluid through two connections to a valve means 64. The valve means 64 also control the pressure fluid supply to a second double-acting cylinder 54 which has a piston rod 56 adapted to push a charging shoe which registers with a gap 52 in the guideway 50 over the die opening 34 and to retract the shoe into the guideway 50. For this

purpose contour members

44, 46 are provided on the table in front of and behind the die opening 34. The contour of these members corresponds with the contour of the saddle members 49 which close the arches 42 in the bottom of the charging shoe 40.

Each charging shoe 40 is associated with a hopper S8 and as soon as it reached a position in the guideway 50 below the associated hopper 58 it is charged with powder from that hopper.

The embodiment in FIG. 5 substantially agrees with that in FIG. 4, excepting that instead of the charging shoes being traversed by hydraulic cylinders, the guideway 50' in the present case is provided with a central longitudinal slot which accomodates a cable or chain 72 provided with driving dogs 74. The cable 72 is driven in either direction by conventional drive means not shown in the drawing. It will also be understood from FIG. 5 that the

contour members

46, 44 may be exchangable members which permit the surface configuration of the die opening 34 to be varied simply by replacing the

members

44, 46. The change in the shape of the arches naturally calls for the replacement of the saddles 49 in the baseplate system 48 or of the baseplates themselves.

FIG. 6 is an end view of a charging shoe 40 mounted on a baseplate which can be traversed along the guideway 50' by an abutment member 76 projecting from the underside of the baseplate 80 being engaged by a driving dog 74 attached to a cable 72. The baseplate 80 is formed all round with a retaining ledge 86 excepting on one side towards which the charging shoe can be pushed off the baseplate. The baseplate 80 may either rigidly or detachably and flexibly coupled by couplers 88 to the preceding respectively following baseplates.

For the purpose of pushing the charging shoe 40 off the guideway 50 or 50' the leading end of the piston rod 56 is fitted with spring-loaded catches 57, as shown in FIGS. 8 and 9. The leading end of the piston rod 56 can thus enter an open-ended slot 84 formed in a cleat 82 secured to that side of the charging shoe which faces away from the die opening 34. When the piston rod 56 is retracted the spring catches 57 engage the back of the slotted part of the cleat 82 and are thus able to push the charging shoe off its guideway 50 and back again into the guideway. When the charging shoe 40 continues its traversing motion to the left in FIG. 7 the end of the piston rod automatically slides out of the openended slot 84 in the cleat.

What we claim is:

1. A pressing apparatus for transforming volumes of powder-like material into compacted bodies. comprismg a table,

a die chamber within said table and having a filling opening defined by parts of said table,

compacting means cooperating with said die chamber for compacting the contents thereof,

guideway means laterally spaced from said filling opening,

a connecting portion on said table between said guideway means and said filling opening,

a plurality of charging frames, each frame defining a hollow space and having an open top for receiving powder-like material, and an open bottom for the discharge of said material,

first means for moving said frames along said guideway means,

second means for moving said frames out of said guideway means and along said connecting portion on top of said filling opening and back, and

means for closing said bottom opening outside of said filling opening.

2. An apparatus according to claim 1 wherein the means for closing the bottom opening comprises baseplates to which said frames are detachably connected.

3. An apparatus according to claim 1 wherein the means for closing, the bottom openings comprise cooperating profile means at the bottom of said frames, and at the surface of said connecting portion.

4. An apparatus according to claim 3 wherein the surface of the table in prolongation of said connecting portion beyond said filling opening and adjacent to it, is provided with similar profile means as said connecting portion.

5. An apparatus according to claim I wherein coupling means are provided for detachably connecting adjacent frames on said guideway means.

6. An apparatus according to claim 1 wherein the means for closing the bottom comprise baseplates within said guideway means to which baseplates said frames are detachably connected, said baseplates cooperating with said first means for moving said frames along said guideway means.

7. An apparatus according to claim 1 wherein said first means for moving said frames comprise chain means underneath said guideway means, dogs mounted on said chainlike means, and means cooperating with said dogs for transmitting a driving force from said chain-like means to said frames.

8. An apparatus according'to claim 1, wherein said second means comprise a ram having a free piston end movable in parallel to said connecting portion, cooperating means at said free piston end and each frame for temporarily connecting said free piston end with a frame.

Claims

1. A pressing apparatus for transforming volumes of powder-like material into compacted bodies, comprising a table, a die chamber within said table and having a filling opening defined by parts of said table, compacting means cooperating with said die chamber for compacting the contents thereof, guideway means laterally spaced from said filling opening, a connecting portion on said table between said guideway means and said filling opening, a plurality of charging frames, each frame defining a hollow space and having an open top for receiving powder-like material, and an open bottom for the discharge of said material, first means for moving said frames along said guideway means, second means for moving said frames out of said guideway means and along said connecting portion on top of said filling opening and back, and means for closing said bottom opening outside of said filling opening.

5. An apparatus according to claim 1 wherein coupling means are provided for detachably connecting adjacent frames on said guideway means.