U.S. patent number 3,672,245 [Application Number 05/124,071] was granted by the patent office on 1972-06-27 for wrench.
Invention is credited to Charles F. Hoffman.
United States Patent |
3,672,245 |
Hoffman |
June 27, 1972 |
WRENCH
Abstract
Pliers for positively gripping a selected work piece between
substantially parallel gripping jaw surfaces, one of which is
carried by a fixed handle, the other of which is carried by a
pivoted toggle member mounted on an extension of the fixed handle
for pivotal movement and adjustment toward and away from the jaw on
the fixed handle, a handle pivotally connected to the toggle member
and tensioning means connecting said handles and adjustment means
on the fixed handle and having pivotal connection with the pivoted
handle whereby the gripping effort on a selected work piece may be
adjusted to secure a strong positive grip thereon without causing
damage to the work piece.
Inventors: |
Hoffman; Charles F. (Chardon,
OH) |
Family
ID: |
22412570 |
Appl.
No.: |
05/124,071 |
Filed: |
March 15, 1971 |
Current U.S.
Class: |
81/367;
81/414 |
Current CPC
Class: |
B25B
7/10 (20130101); B25B 7/123 (20130101) |
Current International
Class: |
B25B
7/10 (20060101); B25B 7/00 (20060101); B25B
7/12 (20060101); B25b 007/12 (); B25b 007/04 () |
Field of
Search: |
;81/407,414,367-380,382,384,386,385 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Condon; Theron E.
Assistant Examiner: Parker, Jr.; Roscoe V.
Claims
I claim:
1. Pliers comprising a fixed handle of channel cross section, a
supporting extension laterally extending from the fixed handle, a
member pivotally supported on said extension, a work piece gripping
jaw on said fixed handle, a gripping jaw on said pivoted member
cooperating with the fixed handle jaw for gripping a work piece
therebetween, means pivotally connecting a movable handle with said
member, a toggle bar pivotally connecting said movable handle with
an end portion of the fixed channelled handle, said supporting
extension having a flat outer surface and a closed longitudinal
slot extending lengthwise of the extension, a series of
substantially arcuate channels formed in the inner surface of said
extension and forming spaced apart arcuate ribs between adjacent
channels, said pivoted member having a substantially arcuate rib on
its under surface for engagement in a selected channel on the
extension, and means carried by the pivoted member consisting of a
headed bolt passing through the slot, the headed portion overlying
the flat outer surface of the extension, the shank portion of the
bolt extending through the slot and through an opening in said
pivoted member to allow longitudinal adjustment of the pivoted
member along said slot for selecting the channel on the extension
in which the rib on the pivoted member is to have sliding
engagement, a compression spring exerting a force of compression
against said pivoted member outer surface, and a nut adjustable
along the bolt for applying compression to the spring to releasably
maintain the rib on the pivoted member in the selected channel on
the extension.
2. The invention defined in claim 1 in which the toggle bar lower
end portion is in abutting engagement with an axially adjustable
threaded member in the fixed handle lower end to thereby select the
degree of locking pressure exerted through the toggle bar to the
movable jaw when the handles are moved to close the jaws upon a
work piece.
Description
NATURE AND OBJECT OF THE INVENTION
The invention is an improvement in pliers in which an improved
toggle connection between a fixed handle and jaw and the pivoted
handle and jaw provides means for applying positive gripping
pressure upon a work piece to be gripped between the jaws and then
releasably locking the work piece while it is being gripped between
the jaws when it is desired to release the piece.
By this invention and due to its unique construction, a large
number of gripping and locking positions of the jaws may be
employed for each adjustment of the stop screw in the fixed handle
and through the link connecting these handles.
THE DRAWING
FIG. 1 is a side elevation of the pliers embodying my invention
showing the relative positions of the parts in solid lines when a
selected work piece of relative small size is gripped and locked
between the jaws; as shown in broken lines, the relative positions
of the movable handle and link bar when the movable handle is in
released position to remove the piece from the gripping jaws.
FIG. 2 is a view similar to that shown in FIG. 1 when a much larger
work piece is gripped and locked between the jaws.
FIG. 3 shows another selection of adjustment of the movable jaws
wherein its fulcrum is shown locked in a position intermediate the
positions shown in FIGS. 1 and 2, along the slotted arm fixed to
the fixed handle.
FIG. 4 is an enlarged fragmentary section taken in the direction of
line 4--4 of FIG. 3.
DESCRIPTION
As illustrated in the drawing of an embodiment of my invention, the
plier consists essentially of a fixed handle 1 of channel form
having a jaw portion 2 on the upper end thereof, and an adjustment
screw 3 and blocking nut 4 carried on the opposite end, a
channelled handle 5 pivotally connected at 6 with a member 7 having
a second jaw cooperating with the jaw 2 for gripping a work piece
"W" therebetween.
The handle 1 is provided with a rigid extension 9 protruding
laterally in the direction of the member 7 and is slotted at 10 to
receive a headed adjusting bolt 11 carried by the extension 9 and
which is movable along the slot to a desired position where it may
be locked against sliding motion along the slot by means of a nut
12 threaded on to the bolt to compress a coiled spring 13 on the
shank of the bolt engaging the base of the nut and the adjacent
walls of the extension 9 as clearly shown in FIG. 4, thereby
effecting a selected spacing of the jaws 2 and 8 for accommodating
a selected size or shape of workpiece.
In order to provide pivotal motion between the members 7 and 9 at a
selected adjustment of the spacing of the jaws, the extension 9 is
formed on its inner surface with a series of spaced apart
substantially arcuate ribs 14 alternately arranged between the
curved channels 15 respectively, and the member 7 is formed with a
substantially arcuate rib 16 for travel along a selected channel
and the adjacent ribs intermediate the selected channel when the
handles are moved toward each other as in gripping a work piece in
the jaws.
The member 7 being pivotally connected at 6 with the upper portion
of the movable handle 5 and also pivotally movable about the axis
of the bolt 11 adjustable along the slot 10, provides a leverage
means whereby effective gripping pressure on the work piece may be
imposed when the handles are moved relatively toward each other
with a minimum of effort. By withdrawing the nut 12 along the bolt
to reduce the thrust of spring 13 against the outer face of the
member 7, the member 7 may be raised sufficiently to disengage the
rib 16 from any one of the channels 15 in which it is engaged and
then dropped into another selected channel of the series to space
the jaws sufficiently to receive a work piece of given size and
shape between the jaws preparatory to applying a gripping and
locking pressure on it. Then the nut 12 is turned to increase the
forces of compression of the spring 13 and thus draw the parts 7
and 9 into more intimate contact relationship with one another and
to assure against displacement of the rib from its selected
channel.
It is to be noted that the cylindrical rib is provided with a flat
bearing surface 18 disposed at an angle for mating with a similar
bearing surface 19 of any one of the selected channels 15 to assure
against accidental displacement of the rib from its channel, yet
providing a relatively large bearing area between the engaged
surfaces of the rib and its channel as the handles are moved to and
from piece gripping positions.
A toggle arm 20 is pivotally connected at its upper end as at 21 to
the pivoted handle 5 and at its lower end portion is pivoted to a
bolt shank 22 in the channel of the arm 1. A stop 23 may be formed
on the toggle to engage the base wall of the channel of arm 5.
In operation, with the parts in position to receive a work piece as
in 3, the axis of bolt 12, pin 6 and pin 21 are substantially as
shown, that is, in substantial alignment along an imaginary
straight line intersecting the axis of these members.
However, when a work piece "W" is inserted between the jaws and the
handles are relatively moved toward each other to grip the work
piece as in FIGS. 1 and 2, the axis 6 will be drawn beyond a dead
center position and out of the area of the imaginary line as
indicated in these figures to rotate the member 7 in a clockwise
direction to draw the jaws into positive gripping relation with the
piece "W." To remove the work piece from the jaws, the handle 5 is
moved on its axis in a clockwise direction as indicated in the
dotted line position in FIG. 1, to again return axis of pin 6 to
the position shown in FIG. 3 causing the member 7 to be rotated in
a counterclockwise direction releasing jaw 8 from its gripping
position.
When the jaws are in gripping position, as in FIGS. 1 and 2,
increased tension will be applied to spring 25, but when the jaws
are released as described above, this increased tension of the
spring will assist in drawing the handles in a direction toward
each other.
By adjusting the bolt 3 in the end of handle 1 and locking it by
means of the nut 4 against the end of the handle more or less
locking pressure may be applied to the jaws through the toggle arm
20.
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