Base forming station

Details Base forming station Base forming station

1998-04-10

2000-06-06

Larson, Lowell A.

Metal deforming

By use of closed-die and coacting work-forcer

Cup or shell drawing

723668, B21D 2228

Patent

active

060704470

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

This invention relates to apparatus for forming an outwardly concave profile on an end wall of a container on a punch moveable towards and away from the apparatus, and more particularly, but not exclusively to the dome forming station on a press forming can bodies.
Dome forming stations are described in U.S. Pat. No. 4,930,330 (WEISHALLA) and U.S. Pat. No. 4,372,143 (ELERT) in which the dome forming apparatus comprises a dome forming pad surrounded by a clamp ring having a profile to receive a can bottom as drawn, and resiliently hold a peripheral portion of the can bottom against a peripheral end wall portion of the advancing punch. Although these doming stations have been used commercially they are vulnerable to wear leading to diminished accuracy of alignment.
WO 89/07021 (ADOLF COORS) describes dome forming apparatus in which a relatively rigidly supported dome forming tool is surrounded by a first sleeve resiliently urged to act on an inner annulus of a can bottom while a second sleeve or holder is resiliently urged against a peripheral portion of the can bottom against the dome forming tool. These prior art forming tools are all vulnerable to sliding wear, a risk made greater as clearances increase to permit ingress of dirt or debris.


SUMMARY OF THE INVENTION

This invention seeks to provide apparatus having resilient independent support for each of the dome forming tool, the holding ring, and an ejector sleeve and rapid return to original position. A further objective is to provide a compact apparatus capable of being mounted in the"domer door" of a wall--ironing machine to avoid outrigged cantilever loads and risk of fatigued failure of the mounting bolts which hitherto have been subjected to rapid tensile cyclic load.
Accordingly this invention provides apparatus for forming a profile in an end wall of a drawn or drawn and wall ironed container on a punch, said apparatus comprising: a shape forming pad for deforming a central portion of the end wall to the desired profile, characterised in that: the shape forming pad is resiliently supported in a housing for limited motion relative to the housing in the direction of travel of the punch; said housing includes a peripheral flange to permit fixing to a press, and a side wall portion closed at one end to contain resilient support means for the forming pad.
In a preferred embodiment, the apparatus further comprises a resiliently supported holding ring surrounding the shape forming pad, wherein the holding ring is resiliently supported to co-operate with the punch to impose a holding force on a peripheral portion of the end wall of the container, and the side wall portion of the housing further includes support means for the holding ring.
The holding ring may be supported by fluid pressure, such as compressed air or gas acting on a first piston having a stem to bearings to prevent tilt.
In a further embodiment, the apparatus may include a resiliently supported sleeve interposed between the shape forming pad and the holding ring, the side wall portion of the housing further including support means for the sleeve for ejecting the container after forming the desired end profile. In this embodiment, the first piston has a hollow stem which guides a second piston to urge the ejector sleeve to rise after shaping of the end wall of the drawn container.
The shape forming pad may be guided by an array of linear roller bearings. Preferably a first pair of linear bearings supports the underside of the shape forming pad whilst a pair of adjustable linear bearings is located above the axis of travel of the pad to maintain pad guidance.
In a preferred embodiment the housing comprises an outer housing and the shape forming pad is fixed to a floor of a hollow inner housing, the side wall of which has an outwardly directed flange extending radially beyond the linear bearings.
The flange of the inner housing is supported on an array of springs in the outer housing. Preferably an array of polyurethane springs is used, each polyurethane sprin

REFERENCES:
patent: 5125257 (1992-06-01), Worwag et al.
patent: 5154075 (1992-10-01), Hahn et al.
patent: 5272902 (1993-12-01), Kobak

Affiliated with

Also associated with

Rating

Base forming station does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Base forming station, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Base forming station will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2204912