Information
-
Patent Grant
-
6530099
-
Patent Number
6,530,099
-
Date Filed
Wednesday, July 19, 200023 years ago
-
Date Issued
Tuesday, March 11, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 007 133
- 007 134
- 081 421
- 030 260
-
International Classifications
-
Abstract
A composite pliers has crossed levers, each including a non-metallic body with an exposed metal cutter blade. The pliers includes strengthening and/or retaining structure around a pivot joint which does not extend into handle portions of the levers. This structure strengthens the pivot joint and can help confine the pliers parts in the event of failure. In one embodiment, each lever has a pivot joint strengthening structure insert molded therein, the structure extending into a jaw portion of each lever and protruding from the non-metallic body to form a workpiece engagement surface, such as a cutting blade. In one form, the jaws have more than one row of teeth with adjacent rows offset from each other. When the pliers is assembled from two identical lever members, each row of teeth on one lever will face the offset row of teeth on the other lever so that the peaks of the teeth on one lever fall within the grooves between the teeth on the opposing row. A non-metallic biasing structure is used to bias the jaws of the pliers open.
Description
BACKGROUND
The following relates to opposed-handle tools, such as pliers, cutters and the like, and particularly to tools formed of non-metallic materials. This has particular application to pliers, such as needlenose and lineman's pliers, of both the crimping and cutting types, which are designed for use in applications where they may be exposed to high electrical voltage or current.
Various types of opposed-handle tools have been available for working in applications where live current poses a danger of unpleasant shocks, or even death. Such opposed-handle tools include the types disclosed, e.g., in U.S. Pat. Nos. 5,556,150; 5,503,049; 5,484,641; 4,709,206; 4,023,450; 3,833,953; and 3,082,652. These prior composite opposed-handle tools all afford at least some degree of important electrically insulating, non-sparking and non-marring qualities. In order to withstand the forces normally applied to such tools, relatively large metal reinforcing structures are often provided that extend all the way from the workpiece engaging ends down into the handles. Such relatively large metal reinforcing structures can be undesirable in terms of electrical-sparking, weight, and manufacturing costs.
SUMMARY
An opposed-handle tool can comprise levers formed almost entirely of non-metallic material with a metal reinforcing structure embedded in the levers around the pivot joint.
An opposed-handle tool can further comprise a pivot mechanism passageway cooperatively formed by a first opening in the first reinforcement structure and respective second and third openings in the first and second pivot joint portions. The pivot mechanism can be inserted in the pivot mechanism passageway and used to interconnect the first and second pivot joint portions. The first opening can be sized and shaped to allow the first reinforcement structure to engage the pivot mechanism and the second and third openings can be sized and shaped to minimize engagement between the pivot joint portions and the pivot mechanism.
The disclosed opposed-handle tool consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the disclosed opposed-handle tool.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of facilitating an understanding of the disclosed opposed-handle tool, there is illustrated in the accompanying drawings an embodiment thereof, from an inspection of which, when considered in connection with the following description, its construction and operation, and many of its advantages should be readily understood and appreciated.
FIG. 1
is a perspective view of one form of the pliers described herein;
FIG. 2
is a perspective view of one lever of the pliers of
FIG. 1
;
FIG. 3
is an exploded perspective view of the pliers of
FIG. 1
;
FIG. 4
is an enlarged top plan view of the pliers of
FIG. 1
;
FIG. 5
is an enlarged sectional view taken along the line
5
—
5
in
FIG. 4
; and
FIG. 6
is an enlarged sectional view taken along the line
6
—
6
in FIG.
4
.
DETAILED DESCRIPTION
Referring to
FIGS. 1
,
3
and
4
, there is illustrated an opposed-handle tool, such as a pivotal hand tool in the nature of a plier/cutter tool
20
. The tool
20
includes a pair of elongated lever members
21
and
21
A which are substantially identical in construction. Accordingly like parts of the lever members
21
and
21
A bear the same reference numbers with the reference numbers of the lever member
21
A bearing the suffix “A” for purposes of distinguishing the two lever members. The following description will be principally with respect to the lever member
21
, and it will be appreciated that, although they may not all be specifically mentioned, the lever member
21
A has like parts.
Referring also to
FIG. 2
, the lever member
21
includes an elongated handle portion
22
at one end thereof and a workpiece engaging end, such as jaw
30
, at the other end thereof. Handle portion
22
and jaw
30
are interconnected by a reduced-thickness pivot joint portion
23
, which has a flat, planar inner surface
24
bounded at the rearward and forward ends thereof, respectively, by shoulder walls
25
and
26
. Formed through the pivot joint portion
23
is a cylindrical bore
27
, that can have a circular, or different shaped, cross-section. In one form, a slot
28
is provided proximate the end of handle portion
22
that is furthest from jaw
30
.
Referring also to
FIGS. 5 and 6
, the jaw
30
has substantially parallel side surfaces
31
and
32
interconnected by an outer surface
33
, which terminates at the forward end of the jaw
30
in a nose surface portion
34
. The side surfaces
31
and
32
are also interconnected by a serrated inner surface portion
35
which is opposite the outer surface
33
and has a plurality of transversely extending, sawtooth-shaped serrations or teeth
36
formed therein to provide a gripping surface. Serrated inner surface portion
35
can comprise two rows
37
,
38
of sawtooth-shaped teeth
36
, wherein the teeth in each row are slightly offset from one another.
The lever member
21
can be of a unitary, one-piece construction, being formed of a non-metallic, non-conducting or electrically resistant composite plastic material, such as a 60% glass-fiber reinforced nylon plastic material known by the trade name GRIVORY and believed to be available through EMS-American Grilon, Inc. In one form, the lever members
21
and
21
A are formed by injection molding, but it will be appreciated that other types of molding could be used.
Referring also to
FIGS. 2
,
3
,
5
and
6
, there are respectively fixedly secured to the pivot joint portions
23
and
23
A of lever members
21
and
21
A, as by a insert molding, two reinforcement structures, such as inserts
40
and
40
A, which are substantially identical in construction. Thus, the parts of the insert
40
A bear the same reference numerals as the like parts of the insert
40
, but with a suffix “A”, but the description will be principally in terms of the insert
40
, in the same manner as is described above in connection with the lever members
21
and
21
A.
In one form, insert
40
is of unitary, one-piece construction and made from steel. However, the insert can also be formed of any other suitable material. The insert
40
is disposed in the pivot joint and can be substantially parallel to the inner surface
24
thereof. Each insert
40
has a bore
42
therethrough disposed substantially congruent to the cylindrical bore
27
in the associated pivot joint portion
23
or
23
A. In one form, bores
27
and
42
both have a circular cross-section having the same axis, with the circular cross-section of bore
42
being smaller in diameter than the circular cross-section of cylindrical bore
27
. Each insert
40
can be disposed in the associated pivot joint portion
23
or
23
A so that the top of insert
40
is in the same plane as, or protrudes slightly above, inner surface
24
.
Each reinforcing insert
40
can be of a complex shape with one or more indentations
44
, openings and/or protrusions
45
, which can be filled, or surrounded, with the plastic material as the inserts
40
are insert molded, thereby anchoring the reinforcing insert
40
in the lever member
21
and helping to prevent pieces of the pivot joint portion
23
from breaking off in the event of an overload failure. In one form, insert
40
is sized and shaped to substantially surround the cylindrical bore
27
in pivot joint portion
23
in order to provide added strength to the pivot joint portion and does not extend any substantial amount into handle portion
22
. As illustrated in
FIG. 2
, insert
40
can be designed so that it does not extend into handle portion
22
at all. The various indentations
44
, openings, or protrusions
45
can be used as alignment surfaces to engage positioning surfaces (not shown) in the mold. In one form, at least two alignment surfaces are used in order to properly align insert
40
when insert
40
is insert molded. The interior of bore
42
can also be used as a third alignment surface.
Insert
40
can extend into jaw
30
in order to strengthen jaw
30
and/or to provide a workpiece engagement structure, such as a blade
47
of a wire cutter
49
or a wire crimper, that protrudes from the material that forms the rest of jaw
30
. In another form, insert
40
does not form a blade
47
protruding from the material that forms the rest of jaw
30
. Instead, insert
40
is not exposed to the environment when tool
20
is assembled.
In one form, the workpiece engagement structure can be formed from one of the positioning surfaces, such as protrusion
45
. Such protrusion
45
can be in an unsharpened state when used as a positioning surface. After insert molding, the tool
20
can be assembled with the protrusions
45
and
45
A left unsharpened in order to form wire crimpers (not shown). If wire cutters are desired, the protrusions
45
and
45
A can be sharpened (before or after tool
20
are assembled) in order to form blades
47
and
47
A.
It is advantageous to provide at least one surface
46
on jaw
30
that slopes toward protrusion
45
or blade
47
and forms an access way to allow easier access to sharpen protrusion
45
or blade
47
. A second sloping surface
48
can be provided opposite surface
46
to allow both sides of protrusion
45
or blade
47
to be sharpened and to allow cut wire to be easily extracted from tool
20
.
In assembly of the lever members
21
and
21
A, they are arranged in intersecting relationship, with the pivot joint portions
23
and
23
A overlapping, with the inner surfaces
24
and
24
A in facing relationship and with the bores
27
,
27
A,
42
and
42
A coaxially aligned. The lever members
21
and
21
A can then be pivotally interconnected by a pivot assembly
50
(FIGS.
3
and
5
), which includes a pin
51
and two non-conducting caps, such as plastic heads
52
and
53
. Plastic heads
52
and
53
can further comprise a deformable plastic tube
54
and
55
. In one form, at least one barb
57
is provided on each end of pin
51
to engage the deformable plastic, thereby keeping the pin
51
and heads
52
,
53
together.
A first end of pin
51
is inserted into head
52
, such as into the attached deformable plastic tube
54
, and the resulting coupling is inserted into the pivot mechanism passageway, comprising the aligned bores
27
,
27
A,
42
and
42
A, through the tool
20
. Head
53
is then placed in position so that the second end of pin
51
can be inserted into deformable plastic tube
55
until each head
52
and
53
is held firmly against one of the outer surface of one of the lever members
21
and
21
A. Thus, the pin
51
, deformable plastic tubes
54
,
55
and the heads
52
,
53
cooperate to define a pivot shaft interconnecting the lever members
21
and
21
A for pivotal movement between the closed condition illustrated in FIG.
4
and an open condition illustrated in FIG.
1
. The pin
51
is inserted into heads
52
and
53
until the parts are firmly secured together while allowing substantially free pivotal movement. The heads
52
,
53
are formed of an electrically non-conducting material, such as a suitable plastic or rubber, and they cooperate with the pivot joint portions
23
and
23
A to completely enclose the pivot assembly
50
, so that no metallic portion thereof is exposed.
In one form, a wear resistant shaft
56
surrounds at least one of deformable plastic tubes
54
and
55
. When assembled, the wear resistant shaft
56
engages bores
42
and
42
A, whereas other portions of the heads
52
and
53
have a small gap between them and the plastic material defining cylindrical bores
27
and
27
A that surround them. This enables the wear resistant surfaces of shaft
56
and insert
40
and
40
A to prevent excessive wear by accepting most of the frictional forces as the pliers are used. Even if heads
52
and
53
engage the plastic material defining cylindrical bores
27
and
27
A, the plastic material will wear during initial use and eventually shaft
56
and inserts
40
and
40
A will take most of the wearing forces. In a similar fashion, the pin
51
cab be made of a suitable wear resistant material and, after being inserted in heads
52
and
53
, a portion can be left exposed for engagement with inserts
40
and
40
A.
When the parts are thus assembled, the inserts
40
and
40
A are disposed in opposed facing relationship so that, when the jaws
30
and
30
A are closed, the outer surfaces of the inserts
40
and
40
A will be disposed in an abutting, substantially coplanar relationship. If inserts
40
and
40
A extend slightly above inner surfaces
24
and
24
A, then inserts
40
and
40
A will protect inner surfaces
24
and
24
A from wear due to friction as the tool
20
is used. Even if the outer surfaces of the inserts
40
and
40
A are coplanar with, or even recessed below, inner surfaces
24
and
24
A, the plastic material forming inner surfaces
24
and
24
A will wear down during initial use and then inserts
40
and
40
A will reduce further wear.
In one form, insert
40
is disposed in the pivot joint at a slight angle with respect to the rest of tool
20
or inner surface
24
, such that protrusion
45
is raised slightly above inner surface
24
and is slightly elevated from the portion of the insert near indentation
44
. When tool
20
is assembled from identical components, protrusions
45
and
45
A are slightly offset from one another such that they are not in the same plane, as seen most clearly in FIG.
6
. This allows protrusions
45
and
45
A to slide over one another, thereby allowing tool
20
to fully close. Utilizing a design that allows protrusions
45
and
45
A to overlap also allows protrusions
45
to protrude sufficiently outside the plastic material to allow material to be cut away to make a cutter, wire stripper or crimper. Even when a portion is cut away to form blade
47
, a sufficient overlap can be provided such that there is enough material exposed to allow multiple re-sharpenings of blades
47
and
47
A.
It will be appreciated that the teeth
36
and
36
A define cooperating gripping surfaces for gripping associated workpieces in a known manner. However, using two offset rows
37
and
38
(and
37
A and
38
A) on each lever member
21
and
21
A allows the lever members to be manufactured as identical parts without any detrimental performance. In this situation, when the identical parts are assembled into tool
20
, then teeth
36
of row
37
interlay with the teeth
36
A (not shown) of row
38
A (not shown) and the teeth
36
of offset row
38
interlay with the teeth
36
A of row
37
A (not shown), as best seen in FIG.
4
. In other words, teeth
36
in lever member
21
will lay in the gaps between teeth
36
A of lever member
21
A, and vice versa. Otherwise, if only one row of teeth
36
is used and the tool is assembled from identical lever members
21
and
21
A, then teeth
36
would contact teeth
36
A and prevent the tool
20
from fully closing. The interlaying of teeth
36
and
36
A prevents excessive wear from repeated contact between both rows of teeth, as would likely occur with conventional designs where teeth from opposite jaws contact one another when a pliers is fully closed. The interlaying of teeth
36
and
36
A also provides an exceptionally strong grip on some thin soft surfaces even as teeth
36
and
36
A become worn.
In one form, a channel or groove (not shown) is provided between rows
37
and
38
. Such a groove further allows the tool
20
to be closed more fully by minimizing contact between the edges of teeth
36
that are nearest the groove in lever member
21
and the edges of teeth
36
A that are nearest the groove in lever member
21
A. This prevents the edges of teeth
36
and
36
A from catching on one another and preventing the pliers from closing.
A biasing member
60
can be provided with tool
20
to bias jaws
30
and
30
A in the open position seen in FIG.
1
. In one form, biasing member
60
is rectangular in shaped and comprised of a suitable flexible non-metallic, non-conducting material having a memory, such as acetal. Biasing member
60
is bent into an arch and a first end
61
is inserted in slot
28
of lever member
21
and the second end
62
is inserted in slot
28
A of lever member
21
A. In one form, the slots
28
,
28
A and biasing member
60
are sized so that a friction fit can be used to keep biasing member
60
in place. In an alternative form, slots
28
,
28
A and ends
61
,
62
can be designed to snap-fit in place. Neither alternative requires the use of metal fasteners.
Except for the pivot assembly
50
and the inserts
40
,
40
A, the plier/cutter tool
20
has no metallic parts, being formed substantially entirely of electrically insulating, non-sparking, non-corroding materials, which are lightweight and non-magnetic.
From the foregoing, it can be seen that there has been provided an improved pivoting hand tool which is of simple and economical construction, and which is largely non-electrically conductive, lightweight, non-sparking, non-magnetic and corrosion resistant, while providing gripping and cutting surfaces which have strength, hardness, toughness and wear resistance. The forgoing improved pivoting hand tool provides a strengthened hand tool with cutters that can be sharpened, while minimizing the amount of metallic material used and exposed.
Claims
- 1. An opposed-handle tool comprising:a first lever formed entirely of non-metallic material, and including a first handle, a first workpiece-engaging end and a first pivot joint portion therebetween; a second lever formed entirely of non-metallic material, and including a second handle, a second workpiece-engaging end and a second pivot joint portion therebetween; a first reinforcement structure embedded in the first pivot joint portion with no portion of the first reinforcement structure being embedded in the first handle; a pivot mechanism interconnecting the first and second pivot joint portions, the pivot mechanism having no exposed metallic portions when the tool is assembled; and a pivot mechanism passageway cooperatively formed by a first opening in the first reinforcement structure and respective second and third openings in the first and second pivot joint portions; the pivot mechanism being disposed in the pivot passageway and interconnecting the first and second pivot joint portions; and wherein the first opening is sized and shaped to allow the first reinforcement structure to engage the pivot mechanism and the second and third openings are sized and shaped to minimize engagement between the joint portions and the pivot mechanism.
- 2. The opposed-handle tool of claim 1, wherein the first, second and third openings are circular and the second and third openings are larger than the first opening.
- 3. The opposed-handle tool of claim 1, wherein the pivot mechanism includes:a first non-metallic head coupled to the first lever proximate a first end of the pivot mechanism passageway; a second non-metallic head coupled to the second lever proximate a second end of the pivot mechanism passageway; and a wear resistant shaft coupled to the first and second non-metallic heads, the wear resistant shaft sized and shaped to engage a portion of the first reinforcement structure surrounding the first opening.
- 4. An opposed-handle tool comprising:a first lever formed entirely of non-metallic material, and including a first handle, a first workpiece-engaging end and a first pivot joint portion therebetween; a second lever formed entirely of non-metallic material, and including a second handle, a second workpiece-engaging end and a second pivot joint portion therebetween; a first reinforcement structure embedded in the first pivot joint portion with no portion of the first reinforcement structure being embedded in the first handle; a pivot mechanism interconnecting the first and second pivot joint portions, the pivot mechanism having no exposed metallic portions when the tool is assembled; and a pivot mechanism passageway cooperatively formed by a first opening in the first reinforcemuent structure and respective second and third openings in the first and second pivot joint portions; the pivot mechanism being disposed in the pivot passageway and interconnecting the first and second pivot joint portions; and wherein the first opening is sized and shaped to allow the first reinforcement structure to engage the pivot mechanism and the second and third openings are sized and shaped to minimize engagement between the pivot joint portions and the pivot mechanism; the pivot mechanism including a first non-metallic head coupled to the first lever proximate a first end of the pivot mechanism passageway, a second non-metallic head coupled to the second lever proximate a second end of the pivot mechanism passageway, a wear resistant shaft coupled to the first and second non-metallic heads, the wear resistant shaft sized and shaped to engage a portion of the first reinforcement structure surrounding the first opening, a first deformable connector coupled to the first non-metallic head, a second deformable connector coupled to the second non-metallic head, and a barbed connector, including a plurality of barbs, connecting the first and second deformable connectors, and wherein a first barb engages the first deformable connector and a second barb engages the second deformable connector.
- 5. The opposed-handle tool or claim 4 wherein the first and second deformable connectors are female connectors and the barbed connector is a male connector.
- 6. An opposed-handle tool comprising:a first lever formed entirely of non-metallic material, and including a first handle, a first workpiece-engaging end and a first pivot joint portion therebetween; a second lever formed entirely of non-metallic material, and including a second handle, a second workpiece-engaging end and a second pivot joint portion therebetween; a first reinforcement structure embedded in the first pivot joint portion with no portion of the first reinforcement structure being embedded in the first handle; and a pivot mechanism interconnecting the first and second pivot joint portions, the pivot mechanism having no exposed metallic portions when the tool is assembled; wherein the first workpiece-engaging end comprises a first jaw having a first row of tooth-like serrations and a second row of tooth-like serrations offset from the first row, the second workpiece-engaging end comprises a second jaw having a third row of tooth-like serrations and a fourth row of tooth-like serrations offset from the third row, and wherein the first row of tooth-like serrations intermeshes with the third row of tooth-like serrations and the second row of tooth-like serrations intermeshes with the fourth row of tooth-like serrations when the first and second jaws are in a closed position.
- 7. The opposed-handle tool of claim 6, and further comprising a first groove separating the first and second rows of tooth-like serrations and a second groove separating the third and fourth rows of tooth-like serrations.
- 8. An opposed-handle tool comprising:a first lever including a first handle, a first workpiece-engaging end and a first pivot joint portion therebetween; a second lever including a second handle, a second workpiece-engaging end and a second pivot joint portion therebetween; a first reinforcement structure embedded in the first pivot joint portion; and a pivot mechanism interconnecting the first and second pivot joint portions, the pivot mechanism comprising: a pivot mechanism passageway cooperatively formed by a first opening in the first reinforcement structure and respective second and third openings in the first and second pivot joint portions; the pivot mechanism being disposed in the pivot passageway and interconnecting the first and second pivot joint portions; and wherein the first opening is sized and shaped to allow the first reinforcement structure to engage the pivot mechanism and the second and third openings are sized and shaped to minimize engagement between the pivot joint portions and the pivot mechanism.
- 9. The opposed-handle tool of claim 8, wherein the pivot mechanism includes:a first head coupled to the first lever proximate a first end of the pivot mechanism passageway; a second head coupled to the second lever proximate a second end of the pivot mechanism passageway; and a wear resistant shaft coupled to the first and second non-metallic heads, the wear resistant shaft sized and shaped to engage a portion of the first reinforcement structure surrounding the first opening.
- 10. The opposed-handle tool of claim 9 wherein the pivot mechanism includes:a first deformable connector coupled to the first head; a second deformable connector coupled to the second head; and a barbed connector, including a plurality of barbs, connecting the first and second deformable connectors, and wherein a first barb engages the first deformable connector and a second barb engages the second deformable connector.
- 11. An opposed-handle tool comprising:a first lever including a first handle, a first workpiece-engaging end and a first pivot joint portion therebetween; a second lever including a second handle, a second workpiece-engaging end and a second pivot joint portion therebetween; and a pivot mechanism interconnecting the first and second pivot joint portions; wherein the first workpiece-engaging end comprises a first jaw having a first row of tooth-like serrations and a second row of tooth-like serrations offset from the first row, the second workpiece-engaging end comprises a second jaw having a third row of tooth-like serrations and a fourth row of tooth-like serrations offset from the third row, and wherein the first row of tooth-like serrations intermeshes with the third row of tooth-like serrations and the second row of tooth-like serrations intermeshes with the fourth row of tooth-like serrations when the first and second jaws are in a closed position.
- 12. The opposed-handle tool of claim 11, and further comprising a first groove separating the first and second rows of tooth-like serrations and a second groove separating the third and fourth rows of tooth-like serrations.
US Referenced Citations (23)
Foreign Referenced Citations (1)
Number |
Date |
Country |
1006041 |
Mar 1977 |
CA |