Work holders – Relatively movable jaws – Means for direct manual adjustment of jaw
Reexamination Certificate
1998-02-02
2001-03-20
Eley, Timothy V. (Department: 3203)
Work holders
Relatively movable jaws
Means for direct manual adjustment of jaw
C269S043000, C269S089000, C269S195000, C269S208000
Reexamination Certificate
active
06202997
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a work vice used when a work is fixed to a table and a work pallet of a machine tool.
Various kinds of work vices for fixing a work to a table of a machine tool, etc. are generally used in accordance with a structure of the machine tool, a shape and a material of the work, etc. A work vice of a general purpose structure is constructed such that a fixed claw is arranged at one end of a fundamental base thereof fixed to the table of the machine tool, and a movable claw is provided in opposing relation to the fixed claw which the moving claw is moved forward and backward along a slide guide on the fundamental base by a screwing operation of a feed screw. Then, the work is fixedly positioned between the movable claw and the fixing claw.
Therefore, one example of a mounting structure of the above movable claw in the work vice disclosed by the present applicant in Japanese Laid-Open Patent Publication No. 7-171769 will next be explained on the basis of FIG.
1
. This mounting structure of the movable claw has a first moving base
18
and a second moving base
19
moved along a slide guide
5
on a fundamental base
3
. Further, an upper semicircular knock hole
112
is formed in a leg portion
25
of the first moving base
18
, and the knock hole
112
forms a circular knock hole by being opposed to one of plural lower semicircular knock holes
17
formed on the fundamental base
3
. The second moving base
19
is the first moving base and the second moving base and can approach the first moving base and can be separated from the first moving base. A movable claw is arranged on a side of the second moving base opposed to the first moving base. A covering roof portion having an arched covering gate shape is provided at an upper portion of the second moving base on its first moving base side. A lower face of a side wall of the pent roof portion and an upper face of the first moving base come in slide contact with each other and form a slide face parallel to the slide guide. Therefore, the length of a structure for supporting the movable claw can be shortened without damaging rigidity. Further, reaction force from a work is applied to an end tip of the cover roof portion and the length of an arm of moment resisting the reaction force is increased. Accordingly, pressure applied to the sliding face is reduced and no excessive force is locally applied so that durability of a work vice device is improved. Further, the sliding face has such-an-action-that it complements the shortening of the guide length of the movable claw by the guide of the fundamental block and the rigidity of the movable claw for the swing in the up and down direction is made high.
In a work vice of a second aspect of the present invention, the pent roof portion of the arched gate shape extends to a side of the first moving base by a length longer than an interval of knock pin holes. An inner face of each of both side walls of the roof portion is set to a guide face coming in slide contact with both side faces of a bearing portion. The sliding face has such an action that it complements the screwed onto a screw rod
23
rotatably inserted into a bearing portion
24
of the first moving base
18
. A moving claw
15
is attached to a side of the second moving base
19
opposed to the first moving base
18
.
When the work is gripped by this work vice, the upper semicircular knock hole
112
of the first moving base
18
is opposed to one of the lower semicircular knock holes
17
of the fundamental base
3
in conformity with a length of the work. The first moving base
18
is fixed to the fundamental base
3
by inserting a knock pin
29
into a formed circular knock hole. Thereafter, the second moving base
19
screwed onto the screw rod
23
is moved forward and backward toward an opposed fixed claw (not shown in
FIG. 1
) side by rotating the screw rod
23
pivotally inserted into the first moving base
18
. Thus, the work is fixedly positioned between the fixing claw and the moving claw
15
attached to the second moving base
19
.
In the work vice of the structure having the first and second moving bases
18
,
19
as shown in
FIG. 1
, a region capable of gripping the work between the movable claw
15
and the fixing claw is narrowed by a length L of the second moving base
19
, or the length of the fundamental base
3
must be increased by this length L in comparison with a work vice having only one moving base. Further, when the work fixedly positioned between the movable claw
15
and the fixed claw is cut, cutting powder of the work enters the clearance between the first moving base
18
and the second moving base
19
so that this cutting powder prevents a function of the work vice, etc.
In this case, as shown in
FIG. 2
, the known of a conventional art, combination of a base block
42
and a claw block
43
is used as the movable claw
15
used in the work vice to more accurately position the work. Namely, this movable claw
15
is formed such that the base block
42
and the claw block
43
can slidably come in contact with each other on a pushing-down face
47
inclined downward. When the work is positioned and fixed by the movable claw
15
, the pushing-down face
47
generates component force for pressing the claw block
43
downward by reaction force F from the work so that the work is pressed against an upper face of the fundamental base
3
or an upper face (fixing face) of a spacer arranged on the fundamental base
3
. In this case, when the movable claw
15
is opened, a tension spring
44
arranged between the base block
42
and the claw block
43
pulls up the claw block
43
.
However, the movable claw
15
of this structure has the following problem. Namely, when the work is gripped by an upper portion of the movable claw
15
, the claw block
43
and the base block
42
come in one side contact with each other and no claw block
43
for gripping the work itself is smoothly moved downward so that no work cannot accurately come in press contact with a desirable fixing face. Further, when a gradient of the pushing-down face
47
is increased to smoothly move the claw block
43
downward by the pushing-down face
47
, thicknesses for increasing the gradient are required with respect to both the base block
42
on a receiving side and the claw block
43
on a moving side. Therefore, the thickness of the movable claw
15
is increased so that the size of a grippable work is limited. Accordingly, a problem is caused in that the movable claw can be used for only a small work.
An arranging interval of a T-groove of the table of the machine tool is different in accordance with kinds and makers of the machine tool. Accordingly, it is necessary to form fixing bolt holes of the work vice in conformity with the arranging interval of the T-groove of the used table. Therefore, problems exist in that a general purpose property of the work vice is lost and several kinds of work vices conformed to the arranging interval of the T-groove of the table must be prepared.
In a certain kind of working, the working is performed by vertically setting a table face. However, when the work vice is fixed to the vertical table in a horizontal direction, a problem is caused in that the knock pin for fixing the fundamental base and the first moving base drops by its light weight. When the fundamental base and the first moving base are fixed to each other by one knock pin, the dropping of the knock pin can be prevented by inserting a flanged knock pin from above. However, when a large work is gripped by arranging work vices in parallel with each other, there is a case in which a stroke length of the knock pin is restricted by an adjacent work vice. Therefore, it is considered that the length of the knock pin is shortened. When the length of the knock pin is shortened, a structure for inserting knock pins from both sides of a vice is used to avoid an offset between an acting center of fastening force of the vice described later and an engaging position of each of the knock pin
Bauer & Schaffer, LLP
Eley Timothy V.
Wilson Lee
Yasuda Seisakusho Co., Ltd.
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