U.S. patent number 3,629,912 [Application Number 05/027,817] was granted by the patent office on 1971-12-28 for clamp and method of making same.
This patent grant is currently assigned to The Chemical Rubber Co.. Invention is credited to Edward M. Klopp.
United States Patent |
3,629,912 |
Klopp |
December 28, 1971 |
CLAMP AND METHOD OF MAKING SAME
Abstract
A one piece, plastic clamp formable from extruded stock. The
clamp comprises a pair of lever arms merged toward one end through
an integral bight portion, to form a generally U-shaped member.
Releasably locking fulcrum means are positioned between the free
and merged ends of the lever arms. The releasably locking fulcrum
extends the full width of the clamp. The cross section of the clamp
through every plane perpendicular to the extrusion axis is
identical in every essential respect.
Inventors: |
Klopp; Edward M. (Seville,
OH) |
Assignee: |
The Chemical Rubber Co.
(Cleveland, OH)
|
Family
ID: |
21839947 |
Appl.
No.: |
05/027,817 |
Filed: |
April 13, 1970 |
Current U.S.
Class: |
24/457; 24/543;
24/535; 24/560 |
Current CPC
Class: |
A47H
13/01 (20130101); D06F 55/00 (20130101); G03D
13/10 (20130101); B01L 9/50 (20130101); Y10T
24/44752 (20150115); Y10T 24/44897 (20150115); Y10T
24/44017 (20150115); Y10T 24/44684 (20150115) |
Current International
Class: |
A47H
13/00 (20060101); A47H 13/01 (20060101); B01L
9/00 (20060101); D06F 55/00 (20060101); G03D
13/02 (20060101); G03D 13/10 (20060101); A44b
021/00 () |
Field of
Search: |
;16/87.2
;24/258,255,248,84,137,137A,255SL |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Griffin; Donald A.
Claims
Having thus described my invention, I claim:
1. A one piece plastic clamp formable from extruded stock
comprising a pair of longitudinally extending lever arms of finite
width merged toward one end through an integral bight portion to
form a generally U-shaped member, the longitudinal axes of said
lever arms in the free state thereof converging outwardly in a
direction away from said free ends, complementary connecting means
formed integrally with and disposed intermediate the ends of said
lever arms, each of said connecting means extending the full width
of its lever arm and facing in the direction of said other lever
arm, each of said complementary means being formed on axes which,
in the free state of said lever arms, converge and intersect
inwardly of said lever arms.
2. The clamp as defined in claim 1, wherein said integral bight
portion comprises a resilient, curvilinear element bowed convexly
in the direction of the free ends of said lever arms.
3. The clamp as defined in claim 2, wherein said curvilinear
element comprises means defining a rest for a clamp supporting
structural member.
4. The clamp as defined as claim 2, wherein said bight portion
further comprises a second resilient, curvilinear element bowed
convexly in the direction away form the free ends of said lever
arms, said curvilinear elements complementing each other in forming
a bight portion of generally orbicular configuration.
5. The clamp as defined in claim 1, further comprising means
operative to releasably lock said opposed gripping surfaces against
a parting force when said complementary connecting means are in
registry with each other.
6. The clamp as defined in claim 1, wherein the merged end of one
of said lever arms extends beyond said bight portion and means are
provided on said extension for supporting said clamp with respect
to a support member.
7. The clamp as defined in claim 1, further comprising means for
releasably locking said lever arms against pivotal movement.
8. The clamp as defined in claim 1, wherein said integral bight
portion comprises a resilient, curvilinear element bowed concavely
in the direction of the free ends of said lever arms.
9. The clamp as defined in claim 1, further comprising at least one
pair of cantilever leaf springs extending inwardly from the merged
ends of said lever arms, the free ends of said leaf springs
engaging each other when said complementary connecting means are in
locking registry.
10. A one piece clamp comprising a pair of cooperating arms having
facing surfaces, said arms interconnecting at one end and
terminating in opposed gripping surfaces at their other ends, pivot
means formed integrally with said facing surfaces and disposed
intermediate the ends of the said arms, said pivot means being
operative to translate a bending force applied to said arms,
between it and the interconnected ends of said arms, into relative
movement between said gripping surfaces, the cross section of said
clamp through every plane perpendicular to the plane of said facing
surfaces being identical in every essential respect, and means for
releasably locking said arms against pivotal movement.
11. A one piece clamp comprising a pair of cooperating arms having
facing surfaces, said arms interconnecting at one end and
terminating in opposed gripping surfaces at their other ends, pivot
means formed integrally with said facing surfaces and disposed
intermediate the ends of said arms, said pivot means being
operative to translate a bending force applied to said arms,
between it and the interconnected ends of said arms, into relative
movement between said gripping surfaces, the cross section of said
clamp through every plane perpendicular to the plane of said facing
surfaces being identical in every essential respect, and at least
one pair of cantilever leaf springs extending inwardly from the
interconnected ends of said arms.
Description
This invention relates to the clamp art and, more particularly, to
one piece, resilient plastic clamp.
Clamps of the type contemplated by the present invention are widely
used in industrial, scientific and domestic applications. For
example, in the industrial area, such clamps are used in
electroplating and pickling operations where small parts held by
clamps are dipped into treating baths and then retrieved. In the
scientific area the clamps find utility in chromatography to fasten
chromatograms to antisyphoning and holding rods, as well as in
X-ray and photographic applications, as film viewing clips. In the
domestic area, the clamps find utility used as clothes pins and
curtain and drapery hardware.
While one piece plastic clamps are known to the prior art, they
have heretofore been manufactured by molding, casting or stamping
operations. These procedures are relatively costly, particularly
when it is recognized that every time a change in dimension of the
clamp is desired, a substantial capital investment in new tooling,
dies and the like must be made.
Another disadvantage of the prior art one piece plastic clip is in
the design of the fulcrum portion of the clamp. Heretofore the
fulcrum portion has been formed either as an integral web or as a
small snap pin. The integral web type of fulcrum suffers the
disadvantage of of being difficult to manipulate and susceptible to
early failure through fatigue cracking. The snap pin type of
fulcrum, because of its small diameter, constitutes a stress
concentrating member and is also susceptible to early failure. In
addition, the snap pin permits lateral rotation between the
gripping jaws of the clamp, and this complicates manipulation of
the clamp.
The present invention overcomes the problems and disadvantages
attendant prior art clamps and method of manufacturing. From the
structural standpoint, the clamp of the present invention is
provided with a releasable locking fulcrum which extends the entire
width of the clamp. This overcomes the disadvantages of both the
prior art fulcrums as described above.
From the standpoint of method of manufacturing, clamps according to
the present invention can be manufactured by a plastic extrusion
process. This permits clamps having different widths, with parallel
and nonparallel sides, to be manufactured without any additional
capital investment to accomplish these modifications.
In addition to obviating certain disadvantages or prior art clamps,
the novel clamp of the present invention provides certain
additional features which are regarded as entirely new in the art.
One of these relates to the provision of means for releasably
locking the arms of the clamp against pivotal movement so that the
article being clamped cannot be accidentally dislodged. Another
relates, in certain embodiments of the present invention, to the
provision of novel means defining rests for supporting members for
the clamps.
In accordance with one aspect of the present invention, there is
provided a one piece clamp comprising a pair of cooperating arms
having facing surfaces. The arms interconnect at one end and
terminate in opposed gripping surfaces at their other ends. The
clamp is provided with pivot means formed integrally with the
facing surfaces and disposed intermediate the ends of the arms. The
pivot means is operative to translate a bending force applied to
the arms, between it and the interconnected ends of the arms, into
relative movement between the gripping surfaces. The cross section
of the clamp through every plane perpendicular to the plane of the
facing surfaces is identical in every essential respect.
In accordance with another aspect of the present invention, there
is provided a one piece plastic clamp, formable from extruded
stock, comprising a pair of lever arms of finite width merged
toward one end through an integral bight portion, to form a
generally U-shaped member. The lever arms have free ends
terminating in opposed gripping surfaces. The clamp is provided
with elongated connecting means formed integrally with and disposed
intermediate the ends of one of the lever arms, the connecting
means extending the full width of the lever arms, and facing in the
direction of the other lever arm. Complementary connecting means
are formed integrally with and disposed intermediate the ends of
the other lever arm, the complementary connecting means extending
the full width of the other lever arms, and facing in the direction
of the first mentioned lever arm. The connecting means and
complementary connecting means are dimensioned and positioned for
locking registry with each other, thereby operating as a fulcrum
for bending moments applied to the lever arms.
In accordance with still a further aspect of the invention, there
is provided a one piece plastic clamp formable from extruded stock
comprising a pair of longitudinally extending lever arms of finite
width with each of said lever arms having a free end defining
opposed gripping surfaces, the longitudinal axes of said lever arms
in the free formed state thereof converging outwardly in a
direction away from the free end of said lever arms, said clamp
further including an integral bight portion interconnecting the
lever arms intermediate the length thereof, and complementary
connecting means positioned on each of said arms between said bight
portion and said free ends with said complementary means being
oriented on their respective lever arms such that in the free state
of said lever arms the central axes on which said complementary
means are formed converge and intersect inwardly of said lever
arms.
It is therefore an object of the present invention to provide an
improved one piece plastic clamp.
Another object of the present invention is to provide a clamp of
the type described which overcomes a certain deficiency of prior
art clamps.
A further object of the present invention is to provide a one piece
plastic clamp formable from extruded stock.
Another object of the invention is to provide a one piece plastic
clamp having releasable locking fulcrum means extending the entire
width of the clamp.
A further object of the invention is to provide a clamp of the type
described comprising means for releasably locking the clamping arms
against pivotal movement.
These and other objects and advantages will become apparent from
the following detailed description of preferred embodiments of the
invention when read in connection with the accompanying drawings,
in which:
FIG. 1 is a schematic perspective view of a clamp together with a
fragmentary portion of an extruded member from which the clamp is
severed;
FIG. 2 is a schematic plan view of the clamp illustrated in FIG. l,
with the fulcrum in its locked position;
FIG. 3 is a schematic section view taken generally along line 3--3
of FIG. l;
FIG. 4 is a section plan view of a modified embodiment of the
invention;
FIG. 5 is a schematic plan view of another modified embodiment of
the invention;
FIG. 6 is a schematic plan view of another modified embodiment of
the invention;
FIG. 7 is a schematic plan view of another modified embodiment of
the invention;
FIG. 8 is a schematic end view of a portion of the locking
mechanism used in conjunction with the embodiment of FIG. 7;
FIG. 9 is a schematic end view taken along line 9--9 of FIG. 8;
FIG. 10 is a schematic plan view of the same embodiment illustrated
in FIG. 7, showing the locking blocks installed and the fulcrum in
its locked position;
FIG. 11 is a schematic plan view of a modified embodiment of the
invention;
FIG. 12 is a schematic plan view of another modified embodiment of
the invention;
FIG. 13 is a schematic plan view of another modified embodiment of
the invention; and,
FIG. 14 is a schematic plan view, similar to FIG. 13, but with the
clamp fulcrum in its locked position.
Referring now to the drawings wherein the showings are for the
purpose of illustrating preferred embodiments of the invention, and
not for the purpose of limiting same, FIG. 1 illustrates extruded
plastic stock member 10 from which has been severed a one piece
plastic clamp designated generally as 12.
With reference to FIGS. 1 through 3, it will be seen that clamp 12
comprises a pair of lever arms 14, 16 of finite width W. While the
width W is shown as being constant in the drawings, it will be
appreciated that the width may be tapered if desired. Arms 14, 16
are merged toward one end through an integral bight portion, which
in this embodiment is defined by resilient, curvilinear element 18,
bowed convexly in the direction of free ends 22, 24 of the lever
arms, and second resilient curvilinear element 20, bowed convexly
in the direction away from the free ends of lever arms 14, 16.
Curvilinear elements 18, 20 complement each other in forming a
bight portion of generally orbicular configuration.
Free ends 22, 24 of the lever arms terminate in opposed gripping
surfaces 26, 28 respectively, which serve to engage opposite
surfaces of the article to be held by the clamp.
Arms 14, 16 are provided respectively, with facing surfaces 30, 32.
Integrally formed on facing surface 30 is elongated connecting
means, which in the embodiment illustrated is defined by rodlike
member 34, which extends the full width of lever arm 14. Integrally
formed on facing surface 32 is complementary connecting means,
which in the embodiment illustrated is defined by elongated socket
36, which extends the full width of lever arm 16. As best
illustrated in FIG. 2, rodlike member 34 and socket 36 are
dimensioned and positioned for locking registry with each
other.
It is noteworthy that the cross section of clamp 12 through every
plane perpendicular to the plane of facing surfaces 30, 32 is
identical in every essential respect. This feature permits clamps
of varying widths to be severed from extruded member 10.
The method of forming plastic clamps, in accordance with the
present invention, comprises the steps of extruding a plastic
material along a first axis in the form of a member having a
generally U-shaped cross section, and thereafter severing a section
from the member through a plane rotated a sufficient number of
degrees from the extrusion axis so that the section defines a
plastic clamp. As illustrated in FIG. 1, a plastic material has
been extruded by conventional means not illustrated and forming no
part of the present invention, along a generally vertical axis, in
the form of member 10 having a generally U-shaped cross section. By
means not shown, but well known to those skilled in the art, a
section of member 10 has been severed through a plane generally
perpendicular to the extrusion axis, forming plastic clamp 12.
It will be appreciated that the plastic clamp may be formed by
severing a section of member 10 through a plane rotated more or
less than the 90.degree. illustrated in the drawings. In either of
these events, there will be provided a plastic clamp having a width
which tapers along the length of lever arms 14, 16. These arms may
be wider at their connected ends than at their free ends, or vice
versa. Those skilled in the art will appreciate that even if
rotated 90.degree. , the plane need not be perpendicular to the
extrusion axis. It is also within the contemplation of the
invention to sever a section from the extruded member though a pair
of parallel planes rotated more or less than 90.degree. from the
extrusion axis. These planes may but need not be perpendicular to
the extrusion axis.
Synthetic organic resins which may be extruded to form plastic
clips in accordance with the present invention include a wide
variety of thermoplastic resins. Thermosetting resins, for example
certain polyester resins, may also be used. Among the useful
thermoplastic resins are included certain polyamides,
polycarbonates, high density polyethylenes, vinyl polymers and
copolymers, polypropylene, and ABS
(acrylonitrile-butadiene-styrene) resins. Of these materials,
polypropylene resins are preferred because the cured plastics
formed therefrom have excellent properties including virtual
immunity to flex fatigue, exceptional resistance to environmental
stress cracking, and outstanding resilience and memory
properties.
Member 10 is preferably extruded in the form illustrated in FIG. 1,
that is with arms 14, 16 slightly spread apart, and rodlike member
34 and socket 36 disengaged. It will be noted that the longitudinal
axes of the arms 14, 16 in the free formed state thereof converge
outwardly in a direction away from the free end of such arms.
Moreover, it is to be noted that the central axes of the rodlike
member 34 and socket 36 converge and intersect inwardly of the
lever arms. After a section member 10 is severed, the resulting
clamp may be formed by forcing rodlike member 34 into socket 36.
This is accomplished by pivoting the arms 14, 16 about the midpoint
of the integral bight portion which brings the longitudinal axes of
the rodlike member 34 and socket 36 into alignment, thereby
permitting the coupling of the two arms. The clamp is then ready
for use.
Depending upon the use to which the clamp is put, it may be
desirable to suspend the clamp from a support member, with free
ends 22, 24 of arms 14, 16 facing downwardly. In the embodiment
illustrated in FIG. 2, the support member 38 may be threaded into
the open space defined by complementary curvilinear elements 18,
20. With support member 38 dimensioned as indicated, and clamp 12
rotated so that free ends 22, 24 face downwardly, it will be seen
that the support member will resist movement of arms 14 and 16
toward each other. This effectively prevents free ends 22, 24 from
inadvertently releasing the article held between them. With the
clamp rotated, as illustrated in FIG. 2, it will be seen that arms
14, 16 can be moved toward each other so that in this position the
article being clamp can be readily released by movement of free
ends 22, 24 away from each other.
FIG. 4 shows a modification of the present invention wherein a
plastic clip is defined by a pair of lever arms 40, 42 merged
toward one end through an integral bight portion defined by
curvilinear element 44. Element 44 is provided with means defining
a rest for a clamp supporting structural member, which in the
embodiment illustrated, takes the form of a section of reverse
curvature 46. This embodiment is well adapted to be supported by a
structural member generally circular in cross sections, having a
radius of curvature approximating that of section 46. When the
clamp is so supported, the combined weight of the clamp and the
article held by the clamp tend to flatten curvilinear element 44,
and this in turn applies outwardly directed forces against the
merged ends of arms 40, 42. This causes the article held by the
clamp to be gripped even more tightly by the free ends of the
arms.
FIG. 5 illustrates another embodiment of the invention wherein arms
50, 52 are merged at one and through a bight portion defined by
curvilinear element 54 having means defining a rest for a clamp
supporting structural member in the form of aperture 56. This
embodiment is well adapted for use where it is desired to thread
one or more clamps on a cylindrical supporting member and limit
removal of the clamps to lateral displacement past the end of the
support member.
FIG. 6 illustrates another embodiment of the invention wherein a
clamp is defined by a pair of arms 60, 62 merged at one end through
a bight portion defined by curvilinear element 64. This embodiment
provides means for releasably locking lever arms 60, 62 against
pivotal movement. This last mentioned means is defined by member 66
formed integrally with lever arms 62, the member being provided
with a plurality of saw teeth 68 adapted to engage projection 69 on
lever arm 60. With proper dimensioning, engagement of one of the
saw teeth 68 with projection 69 will cause curvilinear element 64
to flatten out slightly, forcing interconnected ends of arms 60, 62
away from each other. This, in turn, will increase the pressure
applied by the free ends of arms 60, 62 to opposed surfaces of the
article being held by the clamp.
FIGS. 7 through 10 show another embodiment of the invention wherein
a clamp is formed by a pair of lever arms 70, 72 merged toward one
end through an integral bight portion defined by curvilinear
elements 74, 76 describing a generally orbicular opening. As best
seen in FIG. 7, T-bar extrusions extend inwardly from the points of
merger of arms 70, 72 with curvilinear elements 74, 76. Stepped
blocks 79, illustrated in FIGS. 8 and 9, are each provided with a
channel dimensioned to receive T-bar extrusions 78. A snug fit is
preferred. FIG. 10 shows stepped blocks 79 assembled on T-bar
extrusions 78. Forcing the lower steps in one block into engagement
with the lower steps of the other block, will cause curvilinear
elements 74, 76 to flatten out slightly, which, in turn, forces the
integrally interconnected ends of arms 70, 72 away from each other.
This causes the free ends of arms 70, 72 to apply increased
pressure to the opposed surfaces of an article held by the
clamp.
FIG. 11 shows another embodiment of the invention wherein a clamp
is formed by a pair of arms 80, 82 merged at one end through an
integral bight portion defined by curvilinear element 84. In this
embodiment, the merged end of arm 82 extends beyond the bight
portion and means are provided on the extension for supporting the
clamp with respect to a support member. In the embodiment
illustrated in FIG. 11, the last mentioned means takes the form of
J-hook 86.
FIG. 12 illustrates another embodiment of the invention wherein a
clamp is defined by a pair of lever arms 90, 92 merged toward one
end through an integral bight portion defined by curvilinear
element 94. Here, lever arm 92 extends beyond the bight portion, as
shown at 96. The extension 96 is provided with means for supporting
the clamp with respect to a support member, which means in the
embodiment illustrated is defined by aperture 98 which extends
through the thickness of extension 96.
FIGS. 13 and 14 illustrate another embodiment of the invention
wherein a clamp is defined by a pair of lever arms 100, 102 merged
toward one end through an integral bight portion defined by
curvilinear element 104, bowed concavely in the direction of the
free ends of the arms. Fulcrum means are provided by rodlike member
106 and socket 108 both of which extend the full width of arms 100,
102 respectively. In FIG. 13 the fulcrum means is shown disengaged,
and in this configuration illustrates the profile which may be
taken by the extrudate from which the clamp is formed. In FIG. 14
the clamp is shown in its assembled position, ready for use.
As best seen in FIG. 13 the clamp is provided with auxiliary spring
means which in the embodiment illustrated take the form of
cantilever leaf springs 110 which extend inwardly from the merged
ends of arms 100, 102. The leaf springs extend the full width of
the clamp, and taper toward their free ends. The reason for the
tapering can best be explained in conjunction with FIG. 14. With
rodlike member 106 locked in socket 108, the free ends of leaf
springs 110 engage applying normal outwardly directed forces
against merged ends of arms 100, 102. When an inwardly directed
pressure is applied against the merged ends of arms 100, 102, the
area of contact between leaf springs 110 increases. As a
consequence of the leaf springs being tapered the stiffness of the
springs increases as more pressure is applied to arms 100, 102. The
last increment of area contact between the leaf springs is
represented by an incrementally thicker cross section of leaf
spring than the next preceding increment of area contact. It
follows that the thicker the article being gripped between the
facing surfaces of the free ends of arms 100, 102, the greater the
gripping force.
The present invention has been described in conjunction with
certain structural embodiments. However, it will be appreciated
that various structural changes may be made in the illustrated
embodiments without departing from the intended scope and spirit of
the present invention.
* * * * *