U.S. patent number 3,850,490 [Application Number 05/409,439] was granted by the patent office on 1974-11-26 for grounding clamping lever.
This patent grant is currently assigned to The Protectoseal Company. Invention is credited to William J. Zehr.
United States Patent |
3,850,490 |
Zehr |
November 26, 1974 |
GROUNDING CLAMPING LEVER
Abstract
A spring loaded clamp having handle members each with integrally
formed cooperating jaw members, each provided with an angularly
positioned, hardened steel, pointed pin adjustable anchored in the
ends of the jaws with the pin points extending inwardly and
abutting each other. The two handles and jaws are identical
castings to cut down costs of manufacture. Each handle member is
provided with inwardly extending ears pivotedly anchored together
and provided with a strong torsion spring.
Inventors: |
Zehr; William J. (Des Plaines,
IL) |
Assignee: |
The Protectoseal Company
(Bensenville, IL)
|
Family
ID: |
23620505 |
Appl.
No.: |
05/409,439 |
Filed: |
October 25, 1973 |
Current U.S.
Class: |
439/92;
439/822 |
Current CPC
Class: |
H01R
4/64 (20130101); H01R 11/24 (20130101) |
Current International
Class: |
H01R
11/11 (20060101); H01R 11/24 (20060101); H01R
4/64 (20060101); H01r 003/06 () |
Field of
Search: |
;339/255,14,260,261,266
;24/253,95 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Frazier; Roy D.
Assistant Examiner: Hafer; Robert A.
Attorney, Agent or Firm: Snow; William A. Rummler; Charles
W.
Claims
I claim:
1. A grounding clamp of the class described comprising a pair of
identical handle members, each handle member having a jaw member on
one end and a pair of laterally and inwardly extending ears, the
distance between each pair of ears being identical, one pair of
said ears arranged to overlap the other pair of ears, said pairs of
ears having aligned apertures, means pivotally securing said ears
together, each of said handles having an elongated cut-out, a
helical compression spring wound around said means interiorally of
said ears and having the ends of said spring extending rearwardly
in said cut-outs, the ends of said spring being bent substantially
at right angles laterally outwardly with the terminal ends of said
spring abutting against the inner surface of said handle, said jaw
bored and threaded downwardly and inwardly toward said pairs of
ears receiving an elongated case-hardened set screw, the inward
ends of said set screws being pointed and the points abutting each
other when in place in said jaws, the individual centerlines of
said set screws intersecting at an acute angle, whereby when said
handles are compressed towards each other the set screws will tend
to approach a common center line.
2. the jaws device of claim 1 wherein the set screws are positioned
in said jaws, when said device is inoperative, so that the
individual center lines intersect midway between thejaws with an
angle of about 15.degree. between them and means on said set screws
to prevent displacement thereof after setting.
Description
BACKGROUND OF THE INVENTION
When transferring flammable liquids from one container to another,
it is desirable and mandatory under government regulations to
protect against static sparks, and possible flash fires, by
providing means to drain electrical charges to ground. Clamping
levers of the above general type have been provided with a pair of
handle members each having a pair of spaced inwardly extending ears
but one pair of ears is spaced apart wider on one of the handle
members than on the other handle member to fit thereover and be
pivotally secured together. Each handle member is provided with an
integrally formed jaw through which an extending steel hardened pin
is threaded with the points normally abutting each other and the
pins lying on a common centerline and held in this position under
the action of a spring.
When in use, with the jaws spread apart by compressing the handles
to affix the pointed pins on a metal surface, the pins are no
longer lying on a common centerline so that the pins oppose each
other but rather each lies in an outwardly extending diagonal
direction and hence does not provide the most effective grip on the
metal surface to which the clamp is attached. Also, if the pointed
ends are not aligned when clamping a metal surface, the levers tend
to twist sideways and hence the spring action does not effectively
make a solid grounding clamp.
SUMMARY OF THE INVENTION
A bonding and grounding clamp having a pair of identical handle
elements and each having a pair of identical inwardly extending
spaced ears, each of the ears provided with aligned apertures
through which a pivot pin is inserted to anchor the handles
together, a compression spring wound around the pivot pin with the
legs thereof extending rearwardly and lying against the inner walls
of the respective handle elements to retain the handle elements
spread apart, the forward end of said handle elements forming a
pair of jaws and each jaw having opposed, adjustable, inwardly
extending pointed pins whereby, when the jaws are spread apart for
anchorage to a metal surface for grounding purposes, the pointed
pins will lie in an inwardly or coincidental direction and their
points will, by the spring action, be forced through the metal
surface and into the raw metal to effectively form a good bond and
ground. This pin orientation is very effective in resisting
accidental dislodging of the clamp from the container to which it
is applied.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a bonding and grounding clamp
of the present invention on the upper end and a hand clamp on the
lower end connected together by a flexible cable;
FIG. 2 is an end elevational view taken substantially along the
lines 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view taken on the lines 3--3 of FIG.
1;
FIG. 4 is an enlarged vertical cross-sectional view through the
device of FIG. 1; and
FIG. 5 is a front elevational view similar to FIG. 1 but showing
the jaws opened and clamped to a metal surface for bonding and
grounding the clamp thereto.
DETAILED DESCRIPTION OF THE DRAWINGS
The device of this invention has a pair of handle members or levers
10-12 each contoured and terminating at the upper end, as shown in
the drawing, in one-half of a jaw 14-16. Each lever contains a pair
of depending ears 18-20, 22-24. The ears 18-20 are spaced apart the
same width as the ears 22-24 so that when the levers 10-12 are
positioned together, the ears 18 and 22 will abut each other and
the ears 20 and 24 will also abut each other. The ears are provided
with aligned apertures 26 for the reception of a loose rivet pivot
28. The levers are preferably produced from an alloy of zinc by die
casting.
A very strong compression spring 30 is very loosely wound once
around the rivet pivot 28 with the legs 32-34 thereof extending
downwardly and each terminates in a substantial right angle bend
36-38 whereby the ends thereof abut, respectively, against the
lower end of the elongated recess 40 in the handles 10-12, all as
shown in FIG. 4.
Each jaw 14-16 is provided with a threaded aperture 42 which
extends diagonally downwardly and inwardly at about a 15.degree.
angle from the horizontal. Hardened set screws 44, each having a
pointed end 46, are threaded into the respective apertures 42 until
the pointed ends 46 abut approximately medially between the jaws
14-16.
Of course, the set screws 44 may each be set further apart or
closer, with respect to the inner faces of the jaws 42, depending
upon the thickness of the material to which the clamp is affixed
and to assure a good grounding thereof.
The two levers 10-12 and appurtenances are generally identical,
thereby decreasing costs of manufacture.
Each set screw 44 is provided with a lock washer 48 and nut 50 to
fix the set screws when they are correctly positioned, see FIG. 4,
whereby the set screws become immovable after setting.
One or both of the lower ends 52-54 of the handles 10-12 are
provided with an endwise bore 56 into which the free end of the
cable 58 is inserted and held therein by set screws 60.
As shown in FIG. 1, a hand ground clamp 62 is anchored to the other
end of the cable 58. The hand ground clamp may be secured to any
metal structure forming part of a building, pipe or other metal
structure which will act as an electrical ground, while the clamp
of the present invention may be anchored to the rim of a drum
containing flammable liquid. Thus, when the clamps are
appropriately anchored as aforesaid, or vice versa, any static
electricity generated during the transfer of flammable liquids will
be dissipated to ground.
As especially shown in FIG. 5, because of the downwardly and
inwardly pointed set screws 44-46, when the handle portions of
levers 10-12 are pressed towards each other, the jaws will open
against the pressure of the spring 30 so that the pointed ends 46
of the set screws 44 will be able to spread apart and both lie in a
substantially horizontal plane to clamp to a grounded piece of
metal 70 and then, as the handles are released, the strong spring
30 will cause the pointed ends 46 of the set screws to penetrate
the surface of the metal through any paint or oxides and contact
bare metal to effect a good ground.
It is to be understood that numerous parts of the invention may be
altered or omitted without departing from the spirit of the
invention as defined by the following claims.
* * * * *