Machine element or mechanism – Elements – Cams
Reexamination Certificate
1999-08-25
2001-06-26
Lorence, Richard M. (Department: 3681)
Machine element or mechanism
Elements
Cams
C074S110000, C072S381000, C083S588000
Reexamination Certificate
active
06250177
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cam apparatus for performing processing such as punching, bending, and the like with respect to a workpiece such as a thin plate by means of a tool fitted to a cam slide by causing the cam slide to slide by a cam driver.
2. Description of the Related Art
In a cam apparatus of a suspended or aerial cam type including, for example, a cam driver having a sliding surface with a V-shaped cross section and attached to a lower die base by means of a knock pin, screws, and the like, a cam slide having a sliding surface of a shape complementary to that sliding surface, and a cam-slide supporting base which movably supports the cam slide and is attached to an upper die base by means of the knock pin, screws, and the like, there is an advantage in that it is possible to mount the cam slide on the cam driver in a state in which the cam slide is removed from the cam-slide supporting base and the upper die is not disposed, as well as to effect the positioning, i.e., cutting edge adjustment, of a tool such as a piercing punch attached to the cam slide with respect to, for example, a button die provided in the lower die.
After the cutting edge adjustment, if the cam-slide supporting base is attached to the upper die base by means of the knock pin, screws, and the like, and if the cam slide is attached to the cam-slide supporting base, there are cases where, due to an error in attaching the cam-slide supporting base to the upper die base, an error in attaching the cam slide to the cam-slide supporting base, an error in the disposition of the upper die and the lower die, and the like, the once-set positions of the piercing punch and the button die become offset by more than an allowance, e.g., by more than 0.04 mm to 0.05 mm on one side in the case of the piercing of a thin plate, and the mutual sliding surfaces of the cam driver and the cam slide fail to come into desired surface contact with each other, causing one-sided contact. This can result in the occurrence of burrs in actual processing and the possible incidence of breakage of the piercing punch as it rides over the button die.
SUMMARY OF THE INVENTION
The present invention has been devised in view of the above-described circumstances, and its object is to provide a cam apparatus which is capable of making use of the advantage in the aforementioned cutting edge adjustment in the cam apparatus comprised of a cam driver having a sliding surface with a V-shaped cross section and a cam slide having a sliding surface with a shape complementary to that sliding surface, and which, even if the aforementioned attaching errors and disposition error occur, is capable of ensuring desired surface contact of the mutual sliding surfaces of the cam driver and the cam slide and of overcoming the drawbacks of one-sided contact and the like, and capable of eliminating the occurrence of burrs in actual processing and the possible incidence of breakage of a piercing punch as it rides over a button die.
To this end, in accordance with a first aspect of the present invention, there is provided a cam apparatus comprising: a cam driver having a sliding surface with a V-shaped cross section and adapted to be fixedly supported by a cam-driver supporting base; a cam slide having a sliding surface of a shape complementary to the sliding surface of the cam driver in such a manner as to be slidably brought into contact with the sliding surface of the cam driver; and a cam-slide supporting base for movably supporting the cam slide so that the cam slide can move while being guided by the sliding surface of the cam driver as the sliding surface of the cam slide and the sliding surface of the cam driver are brought into contact with each other, wherein at least one of the cam driver and the cam slide is supported by the supporting base of the at least one of them in such a manner as to be movable in a transverse direction perpendicular to a moving direction of the cam slide.
In the cam apparatus according to the above-described first aspect of the invention, since at least one of the cam driver and the cam slide is supported by the supporting base of the at least one of them in such a manner as to be movable in the transverse direction perpendicular to the moving direction of the cam slide, in the contact of the sliding surface of the cam slide and the sliding surface of the cam driver, at least one of the cam driver and the cam slide can be automatically moved in the transverse direction perpendicular to the moving direction of the cam slide. Thus, it is possible to automatically correct the positional offset of, for example, the piercing punch and the button die due to an error in attaching the cam-slide supporting base to the upper die base, an error in attaching the cam slide to the cam-slide supporting base, an error in the disposition of the upper die and the lower die, and the like. Consequently, it is possible to make use of the advantage in the aforementioned cutting edge adjustment in the cam apparatus comprised of the cam driver having the sliding surface with a V-shaped cross section and the cam slide having the sliding surface with a shape complementary to that sliding surface, and even if the aforementioned attaching errors and disposition error occur, it is possible to ensure desired surface contact of the mutual sliding surfaces of the cam driver and the cam slide, overcome the drawbacks of one-sided contact and the like, and eliminate the occurrence of burrs in actual processing and the possible incidence of breakage of the piercing punch as it rides over the button die.
In accordance with a second aspect of the present invention, in the cam apparatus according to the first aspect, the at least one of the cam driver and the cam slide is disposed with a gap with respect to the supporting base of the at least one of them in the transverse direction perpendicular to the moving direction of the cam slide.
To make at least one of the cam driver and the cam slide movable, a gap may be merely provided as in the cam apparatus in the second aspect, in which case the width of the gap (the width in the transverse direction perpendicular to the moving direction of the cam slide) may preferably be determined on the basis of the total of the aforementioned errors and an allowance of the offset.
In accordance with a third aspect of the present invention, in the cam apparatus according to the second aspect, a resilient means is disposed in the gap, and this resilient means in a fourth aspect of the invention is covered by a slide plate and is secured together with the slide plate to at least one of the cam driver and the cam slide or to the supporting base for supporting the at least one of them. The resilient means may be a leaf spring formed of spring steel, a rubber plate formed of urethane rubber or the like, or a combination of these members in a laminated form.
By disposing the resilient means in the gap, as compared with the cam apparatus which has the gap alone, the possibility of looseness of the cam slide during the operation can be eliminated, thereby making it possible to ensure reliable sliding motion of the cam slide.
In accordance with a fifth aspect of the present invention, in the cam apparatus according to any one of the first to fourth aspects, the cam-slide supporting base includes a base body having a recessed portion and having a pair of side walls defining the recessed portion, and a pair of cam-slide coming-off preventing plates secured to the side walls of the base body, respectively, and the cam slide includes a cam slide body to which a tool is adapted to be attached and on which the sliding surface of the complementary shape is formed, a slide member disposed in the recessed portion of the base body, and a constricted connecting portion which connects the cam slide body and the slide member and is disposed between the cam-slide coming-off preventing plates. In accordance with a sixth aspect of the present invention, in the cam apparatus according to any
Lorence Richard M.
Nixon & Vanderhye
Oiles Corporation
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