US3316749A

US3316749A - Presses

Info

Publication number: US3316749A
Application number: US387835A
Authority: US
Inventors: Beard Jack Herbert
Original assignee: Davy Loewy Ltd
Current assignee: Davy Loewy Ltd
Priority date: 1963-08-13
Filing date: 1964-08-06
Publication date: 1967-05-02
Anticipated expiration: 1984-05-02
Also published as: GB1055993A; DE1950496U

Description

J. H. BEARD PRESSES 5 Sheets-Sheet 1 Filed Aug. 6, 1964 R w v f m% N B w W W E it M w y I m 0 o a m K\\ 1 H 1 mwmmmmmmm wm I um mwm Q: a m o 0 Q 0 0 5 BY MM. wwwm mm ATTORNEXS y 2, 1967 J H. BEARD 3,316,749

PRESSES Filed Aug. 6, 1964 3 Sheets-Sheet 2 INVENTOE IAcK HERBERT BEARD BY {LA -L M'xJDl S y 2, 1967 J. H. BEARD 3,316,749

INVENTOR I J C HERBERT BEARD A I ML. LOLHwQlI J- 6 4%;

A'v-relzNeys United States Patent ()fiice 3,316,749 PRESSES Jack Herbert Beard, Sheflield, England, assignor to Davy and United Engineering Company Limited, Sheffield, England, a British company Filed Aug. 6, 1964, Ser. No. 387,835 Claims priority, application Great Britain, Aug. 13, 1963, 31,845/ 63 9 Claims. (Cl. 72-450) This invention relates to presses.

In presses having extensive surfaces between which the work is to be compressed, the length of the movable beam of the press is limited by the permissible bending moments which may be induced in tie-bars connecting the movable beam to the press operating rams. In conventional presses these tie-bars are rigid and are rigidly attached to the movable beam. If one side of the movable beam moves faster than the other side so that it tilts, a bending moment is exerted on the tie-bars. The greater the distance between the tie-bars the greater the bending moment experienced, so that with a long beam the tiebars or associated structure would be damaged in the event of a sufiicient difference in movement at one end of the beam as compared with the other end. Such a difference in movement could be caused, for example, by control or pump failure in the hydraulic or electric equipment or by the work being asymmetrically arranged about the press centre line.

In one aspect the present invention provides a press having a movable beam connected to drive means through a plurality of tie-bars, each tie bar being pivotally connected at one end to the beam and at the other end to the drive means and arranged to slide in pre-loaded spring guides.

In another aspect the invention provides a press having a vertically reciprocable elongate beam, four tie-bars connecting the beam to drive means, each tie bar having one end pivotally connected to a respective corner of the beam for rotation relative to the beam about a horizontal axis normal to the length of the beam and having its other end pivotally connected to the drive means for rotation relative thereto about a horizontal axis normal to the length of the beam, and guide means associated with each tie-bar, each guide means including pre-loading spring means arranged to urge the guide means to support the tie-bars in a vertical position.

An embodiment of press, in accordance with the invention, will now be described, by way of example only, with reference to the accompanying drawings of which:

FIGURE 1 is a front view of a draw-down bending press, from the direction in which the material to be pressed enters the press,

FIGURE 2 is a side view of the press in the direction of arrow A in FIGURE 1,

FIGURE 3 is a section on an enlarged scale on the line 3-3 in FIGURE 2, and

FIGURE 4 is a section on an enlarged scale on the line 44 in FIGURE 2.

Referring to FIGURES l and 2, the press is mounted on a base 12 at the corners of which four side extensions 13 are secured by bolts 14. A pair of driving crossheads 17:: extend across the short sides of the press. Four hydraulic lifting cylinders 15 mounted in the extensions 13 have rams 16 connected in pairs across the short sides of the press by shafts 17 rigidly secured to the beams 17a. Four vertical tie-bars 18 are arranged at the corners of the press and each has its lower end 20 pivotally connected to one of the shafts 17 so that it can pivot relative to the crosshead 17a about the horizontal axis 19 of its associated shaft 17, and its upper end 21 pivotally con- 3,316,749 Patented May 2, 1967 nected to the upper horizontal elongate beam 22 of the press so that it can pivot relative to the beam about a horizontal axis 22a normal to the length of the beam and parallel to the axis 19. Two hydraulic power cylinders 23 mounted in the base 12 have rams 24 which act on the beams 17a respectively to drive the beam 22 downwards for the working trip of the press.

A movable table 25 is supported in the centre of the press on slides 26 on the top of base 12, and the table is provided with extensions 25a which engage under shoulders 26a on the table supporting part of base 12. The table is movable out of the press, to the left in FIGURE 1, by means of a hydraulic cylinder and ram, not shown, coupleable to the table at 27.

Material to be bent enters the press in the direction of arrow B in FIGURE 2 and after being pressed leaves the press on table 25 which is slid onto a support 25b which forms :an extension of the table supporting part of the press 12. The bent material can be lifted off the table by means of a crane or the like.

Referring to FIGURES 3 and 4 each tie-bar 18 has a substantially rectangular horizontal cross-section and is guided for vertical movement in a guide means 29. Each guide comprises a pair of opposed fixed guide plates 28 carrying phosphor bronze bearing plates 31 having vertical bearing surfaces 31a arranged in planes parallel to the length of beam 22 and a pair of opposed spring loaded guides 30 carrying phosphor bronze bearing plates 32 having vertical bearing surfaces 32a arranged in planes normal to the length of the beam 22. Each guide 30 is acted on by two leaf springs 33, which springs are pre loaded, for example, with a force of 1.42 tons per spring, so that the guides bear against the edges 34 of the fixed guides 28. The guides are arranged in two banks, one above the other, as seen in FIGURE 4, so that there are eight springs acting on each tie-bar 18. Lubrication channels 35 in the bearing surfaces of the phosphor bronze plates may be supplied from lubrication connecting points 36. It will be appreciated that the leaf springs 33 may be replaced by coil springs or any other suitably resilient abutment.

This invention provides that the tie-bars connecting the beam 22 and the

drive rams

24 and 16 are sufficiently rigid to support the press in an open position and yet are flexible enough to permit deviation from an upright position consequent upon dis-similarity of movement of one end of the other beam as compared with the other end. This means that the width of the press can be considerably increased over the width of conventional presses having rigidly connected tie-bars, without danger of damaging the tie-bars. For example, in the embodiment illustrated the tie-bars 18 are spaced in the direction of the length of the beam by a distance of 29 feet 5 /2 inches; consequently the press can press large pieces of mate-rial in a single action.

What I claim is:

1. A press comprising a vertically reciprocable elongate beam, drive means for reciprocating the beam, four tie bars each having a substantially rectangular horizontal cross section connecting the beam to the drive means, each tie bar having one end pivotally connected to a respective corner of the beam for rotation relative to the beam about a horizontal axis normal to the length of the beam, and having its other end pivotally connected to the drive means for rotation relative thereto about a horizontal axis normal to the length of the beam, and guide means associated with each tie bar for urging the tie bars to a vertical position, each guide means including a pair of fixed guide plates having guide surfaces parallel to the length of the beam and a pair of movable guide plates having guide surfaces normal to the length of the beam,

and preloaded spring means arranged to bias the movable plates towards the associated tie bar.

2. A draw-down press comprising a vertically reciprocable elongate beam, four upright tie bars each having a substantially rectangular horizontal cross section, each tie bar having its upper end pivotally connected to a respective corner of the beam for rotation relative to the beam about a horizontal axis normal to the length of the beam, a pair of crossheads below the ends of the beam, the lower ends of each of the tie bars being pivotally connected to the crossheads and mounted to permit rotation relative thereto about a horizontal axis normal to the length of the beam, a pair of vertically reciprocable ram and cylinder assemblies one arranged to act on each crosshead to drive the crossheads, tie bars and beam downwards for the working stroke of the press, and guide means associated with each tie bar for urging the tie bars to a vertical disposition, each guide means including guide members bearing against each surface of the tie bars; and those guide members acting on the surfaces of the tie bars normal to the length of the beam including preloaded spring means arranged to bias the guide members towards their associated tie bars.

3. A press according to claim 1 in which the spring means are leaf springs.

4. A press according to claim 1 in which the spring means are pre-loaded to bias the movable guide plates against the edges of the fixed guide plates.

5. A press according to claim 1 in which the bearing surfaces of the guide means are phosphor bronze.

6. A press according to claim 1 including means for lubricating the bearing surfaces of the guide means.

7. A press according to claim 1 which is a draw-down press in which the drive means includes a pair of crossheads connected across the narrow sides of the press and to which the lower ends of the tie-bars are pivotally connected and including a pair of ram and cylinder assemblies one arranged to act on each crosshead to drive the crosshead and beam downwards for the working stroke of the press.

8. A press according to claim 7 including four lifting cylinder and ram assemblies coupled to the crossheads and arranged to drive the crossheads and beam upwards.

9. A press according to claim 1 including a workpiece supporting table arranged to receive material to be pressed from one direction and including means for sliding the table out of the press in a direction normal from that in which material enters the press to a position in which it clears the beam.

References Cited by the Examiner UNITED STATES PATENTS 8/1965 Ingold 72--451 3/1966 Girodano 72-455

Claims

1. A PRESS COMPRISING A VERTICALLY RECIPROCABLE ELONGATE BEAM, DRIVE MEANS FOR RECIPROCATING THE BEAM, FOUR TIE BARS EACH HAVING A SUBSTANTIALLY RECTANGULAR HORIZONTAL CROSS SECTION CONNECTING THE BEAM TO THE DRIVE MEANS, EACH TIE BAR HAVING ONE END PIVOTALLY CONNECTED TO A RESPECTIVE CORNER OF THE BEAM FOR ROTATION RELATIVE TO THE BEAM ABOUT A HORIZONTAL AXIS NORMAL TO THE LENGTH OF THE BEAM, AND HAVING ITS OTHER END PIVOTALLY CONNECTED TO THE DRIVE MEANS FOR ROTATION RELATIVE THERETO ABOUT A HORIZONTAL AXIS NORMAL TO THE LENGTH OF THE BEAM, AND GUIDE MEANS ASSOCIATED WITH EACH TIE BAR FOR URGING THE TIE BARS TO A VERTICAL POSITION, EACH GUIDE MEANS INCLUDING A PAIR OF FIXED GUIDE PLATES HAVING GUIDE SURFACES PARALLEL TO THE LENGTH OF THE BEAM AND A PAIR OF MOVABLE GUIDE PLATES HAVING GUIDE SURFACES NORMAL TO THE LENGTH OF THE BEAM, AND PRELOADED SPRING MEANS ARRANGED TO BIAS THE MOVABLE PLATES TOWARDS THE ASSOCIATED TIE BAR.