US3422662A

US3422662A - Movable bolster

Info

Publication number: US3422662A
Application number: US657587A
Authority: US
Inventors: Joseph A Geuss
Original assignee: EW Bliss Co Inc
Current assignee: EW Bliss Co Inc
Priority date: 1967-08-01
Filing date: 1967-08-01
Publication date: 1969-01-21
Anticipated expiration: 1986-01-21
Also published as: FR1565085A; DE1752098A1

Description

Jan. 21, 1969 J. A. GEUSS 3,422,662

MOVQBLE BOLSTER Filed Aug. 1, 1967 Sheet 2 of2 FIG.4

l2 v l2 INVENTOR. JOSEPH A. GEUSS ATTORNEYS.

United States Patent 3,422,662 MOVABLE BOLSTER Joseph A. Geuss, Canton, Ohio, assignor to E. W. Bliss Company, Canton, Ohio, a corporation of Delaware Filed Aug. 1, 1967, Ser. No. 657,587 U.S. Cl. 72-448 7 Claims Int. Cl. B21j 13/00; B30b /06 ABSTRACT OF THE DISCLOSURE Apparatus for facilitating die changing in the metal working press including a wheeled bolster or die carrier movable along tracks from a position outside the press to a position on the press bed and beneath the ram. The bolster wheels are arranged to be raised and lowered to permit the bottom of the bolster to be lowered into engagement with the press bed. Additionally, either the bolster or the press are provided with jacks for raising the bolster prior to raising or lowering the Wheels so that the wheel raising and lowering mechanism does not have to lift or lower the weight of the bolster and can, thus, be highly simplified.

The present invention is directed toward the art of presses and, more particularly, to an improved die changing apparatus of the movable bolster type.

The invention will be described with particular reference to its use in die changing and metal working presses, however, it will be appreciated that the invention is capable of broader application and could be utilized wherever it is desired to lower a wheeled die or material carrier into engagement with a subjacent surface.

In the press art it is common practice to provide metal working presses with wheeled carriers or bolsters which are utilized to move die sets into and out of the press.

When used for moving die sets into the press, the die set is positioned on the carrier While it is outside the press. The carrier and die set is then rolled, as a unit, into the press to a position beneath the press ram. At this time, mechanism functions to lower the bottom of the carrier into engagement with the press bed and thus relieve the load of the carrier and dies from the wheels and provide a firm foundation for the lower die and carrier during subsequent press operation.

One of the common means utilized for selectively lowering or raising the carrier has been power actuated mechanisms which function to raise and lower the Wheels relative to the carrier. Because of the tremendous weight of the carrier and 'die set, often as much as 50,000 pounds and higher, the wheel raising mechanisms have been ruggedly built and provided with relatively powerful actuators. Additionally, since actuation of all wheels must take place substantially simultaneously to prevent tilting of the carrier, control systems for the actuators or mechanical interconnections between the various wheels were required.

The present invention overcomes these problems and provides a simplified arrangement for raising and lowering the carrier. The mechanism provided allows each wheel raising actuator to be actuated independently without requiring simultaneous actuation of all remaining wheel raising actuators.

In accordance with the present invention a press of the general type described having a wheeled die carrier provided with wheels movable between carrier supporting and non-supporting positions is provided with the improvement comprising jack means operable when the carrier is in the press for lifting the carrier and the wheels sufiiciently so that the wheels are not supporting "ice the carrier and can, thus, be freely moved between their carrier supporting and non-supporting positions.

Because the movement of the wheels between their supporting and non-supporting positions is accomplished with no load on them, they can be moved by a simply constructed and light weight actuating system. If desired, the wheels can even be manually actuated. Additionally, with the jack means mounted in the press bed, no special controls or hydraulic or pneumatic systems need be provided on the carrier.

Accordingly, a primary object of the present invention is the provision of a press having a simplified movable carrier arrangement.

An additional object is the provision of a press having a wheel raising type of movable die carrier arrangement which eliminates the need for simultaneous actuation of the wheel raising mechanisms.

A further object is the provision of a press with a movable die carrier wherein exact locating of the carrier is accomplished by the mechanism used to lower the carrier into engagement with the press bed.

These and other objects 'and advantages will become apparent from the following description when used to illustrate preferred embodiments of the invention when read in conjunction with the accompanying drawings wherein:

FIGURE 1 is an elevational view somewhat diagrammatic of a metal forming press having an improved movable die carrier arrangement constructed in accordance with one embodiment of the present invention;

FIGURES 2 and 3 are detailed views showing an enlargement of one corner of the carrier with the wheel raising mechanism in the carrier supporting and carrier non-supporting positions, respectively;

FIGURE 4 is a plan view of the bed of the press shown in FIGURE 1;

FIGURE 5 is a view similar to FIGURE 2 showing a second embodiment of the invention;

FIGURE 6 is a cross-sectional view taken on line 6-6 of FIGURE 2;

FIGURE 7 is a cross-sectional view taken on line 7-7 of FIGURE 5; and,

FIGURE 8 is a cross-sectional view taken on line 88 of FIGURE 5.

Referring now to the drawings wherein the showings are for the purpose of illustrating the preferred embodiments of the invention only and not for the purpose of limiting same, FIGURE 1 shows the overall arrangement of a metal working press A provided with an improved movable bolster assembly B constructed in accordance with the preferred embodiment of the present invention. The press A is shown as a relatively conventional metal working press comprised of a bed 10 having an upwardly facing surface 11 and four vertically extending uprights 12 (see FIGURE 4). A ram 14 is carried by the uprights for vertical movement toward and away from the bed 10. Although not shown in FIGURE 1, the press would, of course, include the usual drive mechanism for driving ram 14.

Broadly. die carrier or movable bolster assembly B includes a relatively conventional carrier 15 comprised of a main frame 16 having an upper horizontally extending surface 18 and a lower generally parallel surface 20. The carrier is provided with four wheel units 22 mounted generally at each corner of frame 16. The wheel units are adapted to support the carrier for guided movement along tracks or gui-deways 26 which extend from a position outside the press into and across the press bed. The tracks or guideways could be of a variety of types but are shown as simple grooves adapted to receive the wheels of the wheel units 22.

The arrangement thus far dscribed is relatively conventional and facilitates moving die sets into and out of the press. As shown in FIGURE 1, with the carrier 15 positioned outside the press a die set including upper and lower die halves 28a and 28!) can be positioned on the upwardly facing surface 18 of the carrier. Normally, the lower die half 28b is positively connected to the carrier such as by the use of bolts 29. The carrier is then rolled into the press to a position beneath the ram 14, as shown in solid lines in FIGURE 1. With the carrier in position under the ram, the wheels are moved to a raised or nonsupporting position to permit the lower surface 20 of the carrier to be brought into engagement with the upper surface 11 of the press bed. This removes the load of the carrier and die set from the wheels and provides a rigid foundation and mounting for the lower die half 28b during subsequent press operation. Additionally, the carrier is normally bolted or clamped to the press bed in its lowered position. With the carrier in the lowered position the ram 14 is moved downwardly into engagement with the top surface of the upper die half 28a and clamped or otherwise connected thereto, such as, by bolts 29a. With the die set thus in position the press is ready for operation. To change die Sets the above sequence of operation is reversed and the die set and carrier rolled out of the press and a second die set brought in.

The precise arrangement of the wheel raising mechanisms is not of particular importance to the invention; however, as shown in FIGURES 2 and 3 each of the mechanisms includes a wheel 30 rotatably mounted on a shaft 31 extending between a pair of identical brackets 32. Brackets 32 are mounted for selective rotation on a shaft 34 which extends outwardly from the side of the carrier and is supported at its outer end by a plate 36 which extends down from the carrier frame. The brackets 32 are prevented from rotating in a clockwise direction beyond the position shown in FIGURE 2 by a bracket arm 38 which extends outwardly from the side of the carrier as best shown in FIGURE 6. Extensions 4-0 on the sides of the brackets engage the under surface of the arm 38. However, as shown in FIGURE 3, brackets 32 can be rotated in a counterclockwise direction to move the wheels 30 to a position wherein the lower surface 20 of the carrier can be brought into engagement with the upwardly facing surface 11 of the bed.

Any of a variety of means, power actuated or manual, could be utilized for selectively moving the wheel brackets to their nonsupporting position. The particular means utilized in the preferred embodiment comprise a fluid cylinder 44 which is pivotally connected at one end to a bracket 46 by a pin 48. The piston rod 50 of the cylinder 44 extends outwardly to a bracket 52 which is pivotally connected to the wheel support bracket by a pin 54. Consequently, actuation of cylinder 44 causes the wheels to be pivoted about pivot 34 to move them from the position shown in FIGURE 2 to the position shown in FIGURE 3. Preferably, the cylinder 44 would be actuated pneumatically; however, it is apparent that it could equally well be hydraulically actuated. The means for supplying the necessary pressurized fluid are not shown but can be built directly in the carrier or mounted on the press and connected to the carrier by flexible hoses.

As previously discussed this general arrangement can be utilized for directly raising and lowering the carrier through actuation of the wheels; however, in such case the actuators 44 must be relatively strong and provided with means causing all wheels to be actuated simultaneously. According to the present invention these requirements are overcome and the wheel raising mechanisms actuated by relatively small size cylinders which do not have to be jointly controlled.

According to the invention, this is accomplished by providing jack means which function when the carrier is in the press to lift the carrier and wheels upwardly a very slight amount so that the weight of the carrier and the die set is not supported by the wheels. With the carrier thus lifted. the wheels can subsequently be moved to their non-supporting position and the jack means actuated to lower the bottom of the carrier into engagement with the upwardly facing surface 11 of the bed. When it is desired to move the carrier from the press the jack means are actuated to lift the carrier and die set upwardly away from the bed so that the wheels can be swung to their lowered carrier supporting position. The carrier can then be rolled out of the press.

Although a variety of different types of jacks could be provided for performing this function, they preferably comprise hydraulic jacks positioned in the bed at the locations shown in FIGURE 4. As shown in FIGURE 4, four jack means 60 are positioned in the bed at widely spaced locations. Each of the jack means 60 comprise a hydraulic cylinder 62 having a piston 63 slidably mounted therein. A piston rod 64 extends upwardly from the piston. As is apparent, simply by controlling the supply of hydraulic fluid through line 65 to a position under the piston 63, the movement of piston rod 66 can be controlled to move upwardly against the under side of the carrier frame and lift the carrier upwardly to a position wherein the weight of the carrier is no longer supported by the wheels but is borne by the jacks. The wheel raising mechanisms can then be actuated to 'move the wheels to the position shown in FIGURE 3, and the carrier subsequently lowered into engagement with the press bed.

The present invention also penmits the carrier to be precisely located longitudinally of the track simultaneously with the raising and lowering operation. As shown in FIG- URES 2 and 3, the upper end of the piston rod is provided with inclined surfaces 68. A generally V-shaped opening 70 conforming to the shape of surfaces 68 is provided in the under surface of the carrier and arranged to receive the end of piston rod 66. As can be seen, if the carrier is slightly out of line longitudinally, one of the inclined surfaces 68 will engage a side of V-shaped opening 70 and, through a wedging action, move the carrier to the exact final position. In this manner the jack mean functions to both lift and locate the carrier and eliminates the need for additional locating means.

Although the above-described arrangement is preferred, it is obvious that other arrangements for the wheel raising mechanism and the jacks could be provided. A modified arrangement is shown in FIGURES 5, 7 and 8. According to this embodiment a set of wheels 76 are mounted at each corner of the bolster. Wheels 76 are rotatably connected by axles 77 with

bracket arms

78 and 80. The bracket arms are respectively mounted for oscillation on transversely extending

shafts

82 and 84. The outer ends of the

shafts

82 and 84 are supported by

extensions

86 and 88 which extend downwardly from the underside of carrier frame 16. The upper ends of the bracket arms are connected with

links

90 and 91 by

pivot pins

92 and 93. The lower ends of the links are connected through pivot pin 94 with the end of a lever arm 95. Lever arm 95 is mounted for oscillation about a shaft 96 extending from the side of the bolster or carrier frame.

The means for oscillating arm 95 include a fluid cylinder 98 pivotally mounted from a bracket 100 by a pin 102. The cylinders piston rod 104 is connected through a bracket or clevis 106 and a pin 108 with the upper end of the arm. As can be seen, movement of the piston rod to the left, as viewed in FIGURE 5, causes the wheels to be moved to the dotted line position. Alternately, movement of the rod to the right moves the wheels to their carrier supporting position shown solid. Further movement of the wheels beyond the carrier supporting position is prevented by a stop bar 109 which extends laterally from the side of the carrier frame. As shown, the stop bar is positioned so that the wheels are in what could be termed an overcenter position when they are lowered. Consequently, the weight of the carrier prevents any undesired movement of the wheels while in this position.

The means for raising the carrier so that the wheels may be more readily moved between their raised and lowered position includes a jack means 110 carried by the carrier frame. As noted with regard to the first embodiment, any conventional type of jack means could be utilized; however, as shown, the preferred means include a single acting hydraulic cylinder 112 having a piston 113 carried therein and provided with a vertically extending piston rod 114. A spring 115 serves to bias piston 113 and piston rod 114 to the positionshown in FIGURE 5; however, when hydraulic fluid is supplied through line 117 the piston and rod are moved downwardly until the lower end of the piston rod engages the bed, at which time, further supply of hydraulic fluid causes the carrier to be lifted slightly.

In order to provide exact locating of the carrier simultaneously with the lifting and lowering operation the lower end of piston rod 114 is provided with a pair of inclined surfaces 118. Additionally, a V-shaped opening 120 is provided in the press bed for receiving the end of the piston. Consequently, this arrangement functions in the same manner as that described with reference to the FIGURES 2 and 3 embodiment, in that, during movement of the piston rod to raise the carrier, the inclined surfaces 118 will engage the sides of the V-shaped opening 120 and any longitudinal misalignment of the carrier be readily corrected.

The invention has been described in great detail sufiicient to enable one of ordinary skill in the press art to make and use the same. Obviously, modifications and alterations of the preferred embodiment will occur to others upon a reading and understanding of the specification and it is my intention to include all such alterations and modifications as part of my invention insofar as they come within the scope of the appended claims.

Having thus described by invention, I claim:

1. In a press having a bed with an upwardly facing surface, a ram movable toward and away from said bed surface; a carrier having wheels on which it is supported for movement along guide means from a position outside the press to a position within the press and beneath the ram, said wheels being movable between a first position in which they support the lower surface of the carrier at spaced distance above the bed surface and a second position in which the lower surface can be brought into engagement with the bed surface, the improvement comprising: jack means operable when said carrier is in said second position for lifting said carrier and said wheels sufliciently so that said wheels are not supporting said carrier and can thus be freely moved between their first and second positions.

2. The improvement as defined in claim 1 wherein said jack means are mounted in said bed.

3. The improvement as defined in claim 1 wherein said jack means are mounted in said carrier.

4. The improvement as defined in claim 1 wherein said jack means include a plurality of power driven reciprocable rods arranged to be driven vertically downwardly from said carrier.

5. The improvement as defined in claim 4 wherein said jack means comprise a plurality of reciprocable rods arranged to be driven vertically upwardly from said bed.

6. The improvement as defined in claim 5 wherein at least some of said rods have tapered end portions, and said carrier has tapered openings arranged to receive said tapered rods when said carrier is in said second position and said rods are driven vertically upwardly.

7. The improvement as defined in claim 1 wherein said jack means comprise a plurality of hydraulic cylinders having vertically extending piston rods adapted to en gage said carrier when said cylinders are actuated while said carrier is in said second position.

References Cited UNITED STATES PATENTS 2,913,946 11/1959 Ellrich -299 2,988,234 6/ 1961 Barothy 100-299 3,213,739 10/1965 Zingone 100299 CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner.

US. Cl. X.R.