Presses – Reciprocating press construction – Platen level compensating
Patent
1995-03-07
1996-07-02
Gerrity, Stephen F.
Presses
Reciprocating press construction
Platen level compensating
72450, 83615, 83632, 100282, 100285, B30B 114
Patent
active
055311601
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a single-shaft four-point punch press with a machine frame; an eccentric shaft supported for rotation in the machine frame; a ram guided for a rectilinear reciprocating movement in the machine frame; an arrangement of rods with rod members which are drivingly connected to the eccentric shaft; each other, whereby every lever unit is pivotally mounted individually and independent from the other lever units at a first point to the rod members and pivotally supported at the machine frame at a second point, and includes a respective further pivot point located remote from these two points; pivotally mounted at one end to one of the further pivot points and at the other end to the ram.
The off-center loading of the tools, specifically of the upper tool in such punch presses causes various difficulties and drawbacks. The allowable loading of the tools decreases for a given machine frame size considerably towards the edge areas of the tools and reaches sometimes the value zero. Among others, it is the bearing areas such as, for instance, between push rods and rams and also between push rods and driving members pivotally mounted thereto which are subject to a high wear and increased friction in case of off-center loadings of the tools. Furthermore, an increased wear occurs also at the push rods and at the guides for the ram and in the tool. Additionally, off center loadings cause tilting movements and elastic deformations such as, for instance, a bending of elongated structural members of the punch press and accordingly to a loss of the precision of manufacture of the punched articles produced.
In the European patent application no. 92 116 064.4 a punch press is disclosed which includes single lever units arranged separate from each other, whereby every lever unit is pivotally mounted to the rod members and machine frame, respectively, independently from the other lever units, whereby every respective lever unit is pivotally mounted to a push rod. In case of specifically this punch press, but also of other punch presses, the tool can be mounted to the ram only at such areas which are located at the edge of the tool, i.e. the connecting members, e.g. threaded bolts, by means of which the tool is mounted to the ram, display a large distance from each other. Therefore, due to this unfavorable supporting of the tool it is possible that deformations of the tool occur due to its weight and also due to thermal expansions, which can negatively influence the precision of the articles produced by such punch press, specifically in case of tools having rather large longitudinal dimensions. Furthermore, off center forces laterally relative to the direction of feed of the web are not transmitted at such punch presses without any moments to the pivotal points of the push rods and to the lever units. It is possible that bending moments occur in the push rods and in the pivot pins of the pivot joints.
Here, the invention will provide a remedy. The invention such as defined in the claims solves the object to provide a single-shaft four-point punch press, in which the rods are mounted via ball-and-socket joints to the ram.
The advantages gained by the invention are mainly to be seen, in that in case of off center loadings of the tool no moments are transmitted to the areas where the push rods are pivotally mounted to the lever units. Accordingly, a smaller wear occurs at bearing and connection areas of the press and a decrease of friction forces. Furthermore, although the pivotal points of ball-and-socket joints are located above the ram, the punch press can be kept rather small, such that spring elastic properties of the punch press and the thermal stability of the punch press can be maintained at low levels.
In the following, the invention will be explained more in detail based on the drawings illustrating one embodiment only.
FIG. 1 is a vertical section through a single-shaft four-point punch press;
FIG. 2 is a section along line II--II of FIG. 1;
FIG. 2A is a variant of the design of the push rod; and
FI
REFERENCES:
patent: 1407161 (1922-02-01), Klocke
patent: 2105053 (1938-01-01), Patrick
patent: 2204413 (1940-06-01), Hubbert
patent: 2302132 (1942-11-01), MacMillin et al.
patent: 2375398 (1945-05-01), Wilkins
patent: 4013003 (1977-03-01), Finsterwalder et al.
patent: 4638704 (1987-01-01), Wanibuchi et al.
patent: 4817456 (1989-04-01), Imanishi et al.
patent: 4873923 (1989-10-01), Manning
patent: 5317893 (1994-06-01), Eigenmann et al.
Bruderer AG
Gerrity Stephen F.
LandOfFree
Single-shaft four-point punch press does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Single-shaft four-point punch press, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Single-shaft four-point punch press will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1498563