U.S. patent number 3,713,322 [Application Number 05/104,210] was granted by the patent office on 1973-01-30 for crimping tool.
This patent grant is currently assigned to The Deutsch Company Electronic Components Division. Invention is credited to Milton G. Fischer.
United States Patent |
3,713,322 |
Fischer |
January 30, 1973 |
CRIMPING TOOL
Abstract
A crimping arrangement for attaching a contact to the end of a
wire in which opposed first flat dies are moved inwardly to a
position of spaced adjacency in which they compress the contact
between them, after which opposed second dies with arcuate concave
surfaces and of thicknesses equal to the spacing between the flat
dies are moved inwardly to further compress the contact. The dies
may be movable in straight slots in a carrier member and actuated
by a rotatable cam ring having grooves receiving outer peripheries
of the dies to cause the appropriate sequential movement. Handles
attached to the cam ring and die carrier member permit hand
operation of the tool.
Inventors: |
Fischer; Milton G. (Banning,
CA) |
Assignee: |
The Deutsch Company Electronic
Components Division (N/A)
|
Family
ID: |
22299230 |
Appl.
No.: |
05/104,210 |
Filed: |
January 6, 1971 |
Current U.S.
Class: |
72/409.09;
72/403; 72/402; 29/751 |
Current CPC
Class: |
H01R
43/0424 (20130101); Y10T 29/53226 (20150115) |
Current International
Class: |
H01R
43/04 (20060101); H01R 43/042 (20060101); B21d
009/08 () |
Field of
Search: |
;72/410,402,403
;29/23H,23HC,23HM,23HT,282 ;81/303,341,418,425 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lanham; Charles W.
Assistant Examiner: Keenan; Michael J.
Claims
I claim:
1. The method of attaching a wire to an electrical contact having
an open tubular end portion comprising the steps of
providing a first set of opposed dies with opposed first surfaces
adapted to engage said tubular end portion, providing a second set
of opposed dies with opposed second surfaces adapted to engage said
tubular end portion, inserting the end of a wire into said tubular
end portion, then urging said first set of opposed dies inwardly to
a position where said first surfaces engage and compress a first
part of said end portion therebetween, and then maintaining said
first dies in said position and simultaneously urging said second
set of opposed dies inwardly to a position where said second
surfaces engage and compress a second part of said end portion
therebetween.
2. The method as recited in claim 1 in which said second dies are
displaced substantially 90.degree. from said first dies.
3. The method of attaching a wire to an electrical contact having
an open tubular end portion comprising the steps of
providing a first set of opposed dies with opposed first surfaces
adapted to engage said tubular end portion, providing a second set
of opposed dies displaced substantially 90.degree. from said first
dies,
said second dies having opposed second surfaces adapted to engage
said tubular end portion,
inserting the end of a wire into said tubular end portion,
then urging said first set of opposed dies inwardly to a position
where said first surfaces engage and compress a first part of said
end portion therebetween,
and then maintaining said first dies in said position and
simultaneously urging said second set of opposed dies inwardly to a
position where said second surfaces engage and compress a second
part of said end portion therebetween,
said second dies at said second surfaces thereof being made to a
width substantially equal to the spacing between said first
surfaces of said first dies and received between said first
surfaces when said first dies are in said position thereof.
4. The method as recited in claim 3 in which said first surfaces
are made substantially planar.
5. The method as recited in claim 4 in which said second surfaces
of said second dies are made arcuate.
6. The method as recited in claim 5 in which said second surfaces
of said second dies are made to define cylindrical segments which
are less than semicylinders.
7. The method as recited in claim 3 in which said second dies are
spaced apart when said second dies are in said position
thereof.
8. The method as recited in claim 3 in which said contact is
provided with an inspection opening through said tubular portion,
and in which said first pair of opposed dies and said second pair
of opposed dies so engage and compress said first and second parts
of said tubular portion only outwardly of said inspection
opening.
9. A device for attaching a wire to an electrical contact or the
like having a tubular end portion by crimping said end portion
while said wire is received therein comprising
a duality of first dies having spaced opposed first surfaces,
a duality of second dies having spaced opposed second surfaces,
said first and second dies collectively defining an opening adapted
to receive an electrical contact,
means for moving said first dies relatively toward each other along
a first path to a position in which said first surfaces are in
spaced adjacency for engaging and compressing an electrical contact
therebetween,
and means for then holding said first dies in said position and
simultaneously moving said second dies relatively toward each other
along a second path to a position in which said second surfaces are
in spaced adjacency for further compressing said electrical contact
there-between.
10. A device as recited in claim 9 in which said first path and
said second path are angularly spaced apart substantially
90.degree..
11. A device as recited in claim 10 in which said first surfaces
are planar.
12. A device as recited in claim 11 in which said second surfaces
are arcuate.
13. A device as recited in claim 12 in which said second surfaces
are defined by cylindrical segments which segments are less than
semicylinders.
14. A device as recited in claim 13 in which said second surfaces
are spaced apart when said second dies are in said position
thereof.
15. A device as recited in claim 10 in which said first surfaces
when said first dies are in said position thereof are spaced apart
a distance substantially equal to the widths of said second dies
and said second dies are received therebetween, whereby said second
dies are movable between said first surfaces to said position of
said second dies
16. A device as recited in claim 13 in which said means for moving
said first dies comprises a first cam means.
17. A device as recited in claim 16 in which said means for moving
said second dies comprises a second cam means.
18. A device as recited in claim 17 including an annular member
circumscribing said first and second dies and rotatable relative
thereto, said first and second cam means being incorporated in said
annular member.
19. A device as recited in claim 18 in which
said first cam means is defined by a longitudinally extending
groove in said annular member adjacent each of said first dies,
each of said first dies having a portion receivable in the one of
said grooves adjacent thereto,
said portions being displaceable out of said grooves upon
predetermined rotation of said annular member relative to said
dies.
20. A device as recited in claim 19 in which said means for
maintaining said first dies in said position thereof comprises the
inner periphery of said annular member adjacent said first grooves
therein.
21. A device as recited in claim 19 in which
said second cam means is defined by a second longitudinal groove
adjacent each of said second dies,
each of said second dies having a portion receivable in one of said
second grooves, said portions being displaceable out of said second
grooves upon rotation of said annular member relative to said dies
by an amount greater than said predetermined rotation.
22. A device as recited in claim 21 in which each of said second
dies includes a first member having said second surface thereon,
and a roller at the opposite end of said member for engagement with
said annular member at said second groove therein.
23. A device as recited in claim 22 in which
each of said second grooves includes a first relatively deep
portion, and a second sloping shallower portion,
said relatively deep portion being dimensioned to receive said
roller during said predetermined rotation of said annular member
relative to said dies,
whereby said second dies are not forced inwardly to said position
thereof as a result of said predeter-mined relative rotation.
24. A device as recited in claim 23 in which said means for
rotating said annular member relative to said dies includes a
duality of hand-operable handles.
25. A device as recited in claim 19 in which
said means for moving said first cam means along said first path
and said second cam means along said second path includes a member
having first slot means therein receiving said first dies and
second slot means therein receiving said second dies,
said first and second slot means being spaced apart angularly
substantially 90.degree..
26. A device as recited in claim 25 in which
said first slot means includes a substantially radial portion, and
a substantially longitudinal portion at either end of said
substantially radial portion thereof,
said second slot means includes a substantially radial portion, and
a substantially longitudinal portion at either end of said
substantially radial portion thereof,
each of said first dies being substantially L-shaped with a first
portion in said substantially radial portion of said first slot
means and a second portion in one of said substantially
longitudinal portions of said first slot means,
each of said second dies being substantially L-shaped with a first
portion in said substantially radial portion of said second slot
means and a second portion in one of said substantially
longitudinal portions of said second slot means, and including
spring means engaging said second portions of said first and second
dies for biasing the same toward said annular member.
Description
BACKGROUND OF THE INVENTION:
1. Field of the Invention
This invention pertains to the attachment of wires to electrical
contacts by crimping.
2. Description of Prior Art
In attaching wires to the contacts of electrical connectors,
crimping offers many advantages in speed and convenience. Hand
operated tools have been designed to accomplish contact crimping,
conventionally including four spaced indenters which are actuated
simultaneously to engage the periphery of the contact. This
produces four localized indentations in the contact at which
locations it is deflected inwardly to grip a wire received within
it. Examples of crimping tools of this type are found in U.S. Pat.
Nos. 2,933,000, 2467,012, 3,049,951, 3,063,313, 3,201,969,
3,375,697 and 3,416,213.
Also, for crimping or other forming operations, the use of four
members with arcuate concave surfaces has been proposed.
Arrangements of this type are disclosed in U.S. Pat. Nos.
1,552,162, 3,084,571 and 3,451,249. Again, the members are urged
inwardly at the same time to engage the surface of the contact or
other member in compressing it. Necessarily, there are spacers
between the adjacent indenters or other jaw members for engaging
the contact. Irrespective of the shape of the operative surface,
therefore, the inward force exerted by the indenting member causes
the contact to bulge outwardly between adjacent jaws. An
undesirably large overall lateral dimension can result, producing
an obstruction to the insertion of a contact removal tool into the
contact opening in an electrical connector plug or receptacle. The
localized type of compression that is realized generates only a
limited gripping force on the wire received in the contact. Under
some circumstances, therefore, the wire may be pulled free from the
contact, thereby destroying the electrical connection. Because the
indenters produce only limited areas where the contact is pressed
firmly against the surface of the wire, there can be a relatively
high resistance to the flow of current between the contact and the
wire.
SUMMARY OF THE INVENTION
The present invention provides an improved crimping arrangement in
which the wire is much more securely retained, the electrical
resistance is low and the overall lateral dimension of the contact
end is reduced. In this arrangement, there are first opposed jaws
or dies having adjacent flat surfaces. These dies are moved
inwardly so that the flat surfaces engage the contact and deflect
it to a generally oval configuration. Next, while the first dies
are held in their positions of engagement with the contact,
additional dies are moved inwardly to engage and compress the
exposed sides of the contact. The second dies are of a width
corresponding to the spacing between the first dies when in their
inner positions. Thus, all portions of the contact are confined by
the four jaws, and there can be no outwardly bulging portions. The
second dies have arcuate surfaces, which are concave and defined by
segments of cylinders which are less than semicylinders. The second
dies are moved inwardly a predetermined distance to achieve an
appropriate compression of the contact, which virtually eliminates
any spaces within the makeup of the wire and the contact, providing
instead essentially a homogeneous mass within the contact. The
result is an exceptionally strong mechanical connection, low
electrical resistance and reduced lateral dimension.
To actuate the dies, there may be provided a die carrier member
having transverse slots which receive and guide the dies. A cam
ring circumscribes the dies, engaging them at their outer
peripheries. Initial movement of the cam ring causes the first dies
to be forced out of cam grooves which normally receive them and to
be moved inwardly so that they can engage the contact and will
remain at a predetermined spacing. The cam grooves for the second
dies include relative deep portions of finite length, which will
not bias the second dies inwardly to any appreciable extent as the
first dies are moved to their inner positions. Thereafter, however,
with continued movement of the cam ring, the second dies are forced
out of their cam grooves and accomplish the compression of the
contact. Springs return the dies to their original positions when
the cam ring is returned to its original location. The second dies
may include independent rollers at their outer ends, which are the
members engaged by the cam ring. The rollers can be varied in size
to assure proper positioning of the second dies in the assembled
tool. Also, the rollers reduce friction between the second dies and
the cam ring so that movement of the second dies is
facilitated.
The unit may be incorporated in a hand-operated tool in which the
cam ring is rotated by one handle, while the carrier for the dies
is movable with a second handle. An adjustable stop may be included
to control the amount of rotation of the cam ring relative to the
die carrier member, which, in turn, governs the degree to which the
second dies are forced out of their cam grooves and, hence, the
length of the stroke of the second dies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of an electrical contact and
associated wire which are to be secured together by crimping in
accordance with the present invention;
FIG. 2 is a fragmentary elevational view showing the contact and
the wire between the dies preparatory for the crimping
operation;
FIG. 3 is a view similar to FIG. 2, but with the flat dies moved
inwardly to engage the contact;
FIG. 4 is a view similar to FIGS. 2 and 3 illustrating the final
stage of the crimping operation in which the curved dies are moved
inwardly to engage the contact;
FIG, 5 is a perspective view of the contact after the crimping
operation;
FIG. 6 is an enlarged transverse sectional view showing the wire in
the contact barrel prior to crimping;
FIG. 7 is a view similar to FIG. 6, but after the crimping has
taken place;
FIG. 8 is an elevational view of the crimping tool with one handle
portion partially broken away and the cover plate removed for
clarity;
FIG. 9 is a fragmentary elevational view of the forward portion of
the crimping tool;
FIG. 10 is an enlarged fragmentary view of the crimping tool with
the cover plate removed for clarity, illustrating the first stage
of the crimping operation;
FIG. 11 is an enlarged exploded perspective view of the jaws, jaw
carrier and cam of the crimping tool;
FIG. 12 is a sectional view taken along line 12--12 of FIG. 10;
FIG. 13 is a sectional view taken along line 13--13 of FIG. 10;
FIG. 14 is a sectional view taken along 14--14 of FIG. 10;
FIG. 15 is a sectional view taken along 15--15 of FIG. 10;
FIG. 16 is an enlarged fragmentary sectional view showing the
contact received in the tool for the commencement of the crimping
operation;
FIG. 17 is an elevational view of the crimping tool positioned in
the first stage of the crimping operation;
FIG. 18 is an elevational view of the crimping tool positioned
intermediate the first and second stages of the crimping operation,
and
FIG. 19 is an elevational view of the crimping tool in the second
stage of the crimping operation with both sets of jaws advanced
inwardly.
DESCRIPTION OF THE PREFERRED EMBODIMENT:
The crimping arrangement of this invention will form an attachment
between a wire 10 and a standard contact 11 of the type commonly
used in electrical connectors, as seen in FIG. 1. The contact 11
includes an open cylindrical barrel end 12 that is adapted to
receive the end of the wire 10 from which the insulation 13 has
been stripped. An inspection opening 14 in the wall of the barrel
12 permits the wire 10 to be observed when it is within the barrel
12 so that it can be made certain that the wire has been inserted
far enough. Beyond the barrel portion 12 of the contact 11 is an
annular enlargement 15 defining rearward and forward shoulders 16
and 17, respectively, which normally are used in retaining the
contact within the electrical connector. A forward projecting
portion 18 extends from the enlargement 15, in the embodiment shown
in FIG. 1 this being a pin which is to enter the opening of a
mating socket contact. The invention will operate as satisfactorily
with socket contacts, which also have similar open-ended barrel
portions 12.
The connection between the wire 10 and the contact 11 is made by
crimping the barrel portion 12 of the contact so that it grips the
end of the wire. This is accomplished by the steps shown
schematically in FIGS. 2, 3 and 4. The barrel portion 12 of the
contact 11, with the end of the wire 10 received in it, is
positioned between opposed dies 20 and 21, which have flat end
surfaces 22 and 23. The contact barrel portion 12 also is located
between a second pair of opposed dies 24 and 25, which lie in a
plane which is perpendicular to a plane through the dies 20 and 21.
The dies 24 and 25 have arcuate concave surfaces 26 and 27 adjacent
the contact barrel end 12, these surfaces being identical
cylindrical segments.
In the forming operation, first, the dies 20 and 21 are moved
inwardly a predetermined distance to engage the contact barrel end
12, deflecting it so as to cause it to assume a generally oval
contour as shown in FIG. 3. In the inner positions of these dies,
the flat end surfaces 22 and 23 are spaced apart a distance less
than the original outside diameter of the contact barrel 12, and
substantially equal to the thickness of each of the dies 24 and 25.
Therefore, the spacing between the die surfaces 22 and 23
corresponds to that between the flat sidewalls 29 and 30 of the die
24, and the similar sidewalls 31 and 32 of the die 25. At this
time, the dies 24 and 25 are received between the surfaces 22 and
23, which facilitates the subsequent inward movement of the dies 24
and 25.
Next, with the dies 20 and 21 held in this position, the curved
dies 24 and 25 are advanced toward each other. They are moved
inwardly between the dies 20 and 21 to a position where the arcuate
end surfaces 26 and 27 engage the exposed side portions of the
contact barrel end 12, and advanced inwardly to compress the barrel
end 12 of the contact around the end of the wire 10 (see FIG. 4).
When so moved to their inner positions, the adjacent surfaces 26
and 27 of the dies 24 and 25 are spaced apart, but the contact
barrel 12 is confined on all sides by these dies and the flat dies
20 and 21. There are no gaps through which portions of the contact
can bulge outwardly. With the barrel 12 being compressed completely
around the wire 10, the lateral dimension of the contact barrel is
reduced in all directions. This completes the crimping operation,
and the dies 20, 21, 24 and 25 then are removed from the
contact.
After the crimping operation, the barrel end 12 of the contact has
the general appearance shown in FIG. 5. This includes opposed
flattened surfaces 34 and 35 where the contact has been engaged by
the dies 20 and 21, and opposed curved portions 36 and 37 where the
contact has been compressed by the dies 24 and 25.
FIGS. 6 and 7 are transverse sectional views illustrating the
condition of the barrel portion 12 of the contact and the wire 10
before and after the crimping. The wire 10 consists of a number of
individual strands 10a arranged in a group so as to have a
generally cylindrical exterior. When the wire is fitted within the
tubular barrel portion 12 of the contact 11, necessarily there are
spaces around the various strands 10a. After the crimping
operation, however, as shown in FIG. 7, the strands 10a are
virtually indistinguishable, and the wire 10 presents almost a
homogeneous mass, with no gaps either internally or between the
exterior of the wire and the wall of the contact. This complete
consolidation of the wire 10 and the contact results in an
extremely strong mechanical connection between the wire and the
contact. Also, there are large surface areas of the wire and
contact in intimate engagement so that there is very low resistance
to the flow of electricity. The reduced lateral dimension given the
rearward barrel portion of the contact has a further advantage in
that it facilitates the entry of the removal tool into the opening
receiving the contact when the contact is assembled into an
electrical connector. With the end of the contact being small in
lateral dimension, there is no tendency for the tubular removal
tool to catch on the contact before reaching the retention fingers
within the connector.
The curved surfaces 26 and 27 of the dies 24 and 25 extend through
arcs that are less than 180.degree. so that they are not quite
semi-cylindrical. This allows the dies 24 and 25 to have adequate
strength at the edges of the working surfaces 26 and 27. If the
surfaces 26 and 27 were semicylindrical the dies would taper to
feather edges where the curved surface 26 joins the flat sidewalls
29 and 30, and where the surface 27 meets the sidewalls 31 and 32.
These thin edges inherently would lack strength. Also, where the
final crimped shape of the contact is not made cylindrical, and the
surfaces 26 and 27 are less than semi-cylinders, the edges of the
dies 24 and 25 do not engage at the ends of their inward strokes.
This further helps to avoid damage to the die surfaces.
The dies 20, 21, 24 and 25 may be arranged as jaws in the crimping
tool 39, as seen in FIGS. 8, 10 and 17 through 19. This tool has
general similarity to a pair of pliers, in that it is actuated by
handles 40 and 41 when the contact is crimped.
As shown in particular in FIGS. 11 and 12, the crimping tool 39
includes a central die carrier 42, which has a short forward
cylindrical portion 43 and a rearward cylindrical part 44 of
reduced diameter. A relatively wide transverse slot 45 extends
diametrically across the forward radial face 46 of the portion 43
of the carrier 42. Longitudinal slots 47 and 48 of the same width
connect to the outer ends of the slot 45 and extend to the rearward
end of the forward portion 43 of the carrier 42.
An additional narrower transverse slot 49 extends diametrically
across the forward end of the carrier 42, being perpendicular to
and of the same depth as the slot 45. Longitudinal slots 50 and 51
connect to the outer ends of the slot 49, are of the same width as
that slot and extend to the rearward end of the forward portion 44
of the carrier 42.
The jaws 20 and 21 are L-shaped, having outer portions 52 and 53
and inner portions 54 and 55. When the jaws 20 and 21 are
associated with the carrier 42, the inner portions 54 and 55 of
these jaws are positioned in the transverse slot 45 and aligned
radially of the tool. The outer portions 52 and 53 of the jaws 20
and 21 are located in the longitudinal slots 47 and 48, where they
are engaged on their undersurfaces by compression springs 56 and
57. The latter members are received within openings 58 and 59 which
extend radially with respect to the carrier 42 and are parallel to
the slot 45.
The jaws 24 and 25 also are L-shaped, including outer portions 62
and 63 that fit within the longitudinal slots 50 and 51, while the
inner portions 64 and 65 of these jaws are located in the
transverse slot 49. Compression springs 67 and 68 received in
radial openings 69 and 70 bear against the flat undersurfaces of
the outer portions 62 and 63 of the jaws 24 and 25 (see FIG.
13).
A cover plate 72 having a circular outer periphery and a
frustoconical opening 73 at its center fits over the forward face
46 of the carrier 42. It is attached to the carrier by means of
screws 74, which fit within tapped openings 75 that extend
longitudinally into the carrier 42. The cover plate 72 prevents the
jaws 20, 21, 24 and 25 from falling out of the front of the carrier
42.
Extending around the carrier 42 is a cam ring 76 which has a
cylindrical inner surface 77. The handle 40 of the crimping tool 39
is integral with and extends from the cam ring 76. A pair of
diametrically opposed grooves 78 and 79 in the inner surface 77
extends for the length of the cam ring 76. The grooves 78 and 79
are formed by cylindrical segments which are less than
semicylinders.
A second pair of diametrically opposed grooves 81 and 82 also
extends the full length of the inner surface 77 of the cam ring 76.
The grooves 81 and 82 are displaced 90.degree. from the grooves 78
and 79, and include sloping portions 83 and 84 leading to inner
deeper portions 85 and 86.
The outer portions 51 and 52 of the jaws 20 and 21 have outer
semicylindrical ridges 88 and 89 which are adapted to substantially
complementarily enter the grooves 78 and 79 in the cam ring 76. The
compression springs 56 and 57 urge the jaws 20 and 21 outwardly to
normally hold the ridges 88 and 89 within the grooves 78 and 79.
This is the retracted position of the jaws 20 and 21.
The outer parts 62 and 63 of the curved jaws 24 and 25 have beveled
outer longitudinal surfaces 90 and 91 which lead to outer corners
92 and 93 that engage the inner surface 77 of the cam ring 76
adjacent the inner portions 85 and 86 of the grooves 81 and 82,
when these jaws are retracted as shown in FIG. 8. The compression
springs 67 and 68 for the jaws 24 and 25 urge these jaws outwardly
into this position. Adjacent the beveled outer surfaces 90 and 91
of the jaws 24 and 25, and within the deeper groove portions 85 and
86, are small cylindrical rollers 94 and 95.
Extending around the rearward portion 44 of the carrier 42,
adjacent the rearward radial face 97 of the carrier portion 43, is
a flat plate 98. The latter member is connected to the carrier by
dowel pins 99 that extend through longitudinal openings 100 in the
forward carrier portion 43. An arm 101 is integral with the plate
98 and projects from it.
The handle 41 is in three pieces, two of which are outer, generally
flat sections 102 and 103. The section 102 has an opening 104 that
receives the end of the rearward portion 44 of the carrier 43,
positioning this part of the handle adjacent the plate 98. The
other outer handle portion 103 has an inner opening 105 that fits
around the cover plate 72. Outwardly from the jaw area there is a
spacer 106 intermediate the handle sections 102 and 103, and the
handle assembly is held together by fasteners 107.
A bore extends axially through the die carrier 42, the bore
including a forward portion 109 and an enlarged threaded rearward
portion 110, with a radial shoulder 111 between. A contact
positioning member 112 has a threaded shank 113 that fits within
the threaded portion 110 of the bore, and a radial shoulder 114
that engages the shoulder 111 of the bore. Beyond this is an
unthreaded end portion 115 of the shank that is of reduced diameter
and extends into the forward part 109 of the bore, but is spaced
inwardly from the bore entrance. An axial cylindrical opening 116
is provided in the shank 113 of the member 112, extending inwardly
from the forward radial face 117 of the shank. At the opposite end
of the member 112 is a knob 118, allowing the member 112 to be
rotated into position where the shoulders 111 and 114 are in
interengagement.
In use of the crimping tool 39, the end of the wire 10 is fitted
into the barrel end 12 of the contact 11, and the forward end 18 of
the contact is extended into the axial opening 116 of the member
112. The contact is advanced into the opening 116 a distance
sufficient to cause its forward shoulder 17 to engage the radial
end face 117 of the member 112, as shown in FIG. 16. The parts are
proportioned so that in this position of the contact 11 its
enlarged portion 15 and the forward part of the barrel end 12,
where the inspection hole 14 is located, are within the forward
portion 109 of the bore in the carrier 42. However, the remainder
of the barrel end 12 extends outwardly beyond the bore and is
received within the space between the flat jaws 20 and 21 and the
curved jaws 24 and 25. The rearward end of the contact is
positioned just in-wardly of the outer edges of the jaws.
After this, the handles 40 and 41 are rotated relative to each
other to accomplish the crimping operation. In sequence, rotation
of the cam ring 76 in the counterclockwise direction, as the device
is illustrated, effected by movement of the handle 40, initially
causes the carrier 42 to rotate with it in the same direction. This
occurs because the outer ridges 88 and 89 of the jaws 20 and 21 fit
within the grooves 78 and 79 of the cam ring 76, coupling the jaws
and, hence, the carrier to the cam ring. This simultaneous rotation
occurs for only a few degrees until the arm 101 of the plate 98,
which is connected to the carrier 42 by the dowels 99, engages a
stop 120 carried by the handle 41 between its side portions 102 and
103 (see FIG. 8). This prevents further rotation of the carrier 42
so that the cam ring 76 then must turn relative to the carrier. As
this relative rotation takes place, the reaction at the cam grooves
78 and 79 immediately forces the ridges 88 and 89 of the jaws 20
and 21 out of these grooves. This drives the jaws 20 and 21
inwardly in the path defined by the transverse slot 45 in
opposition to the springs 56 and 57. This inward movement of the
jaws 20 and 21 causes their opposed flat surfaces 22 and 23 to
engage the periphery of the barrel end 12 of the contact,
deflecting the barrel end to a generally oval shape, as shown in
FIG. 3 and discussed above. This position of the tool is
illustrated in FIGS. 10 and 17. This accomplishes the first step of
the crimping operation.
At this time, the rollers 94 and 95 are moved by the cam ring 76 to
locations outwardly of the beveled end surfaces 90 and 91 of the
jaws 24 and 25. However, the rollers 94 and 95 still are within the
deeper portions 85 and 86 of the grooves 81 and 82 so that the jaws
24 and 25 remain substantially in their original positions.
Consequently, only the jaws 20 and 21 initially are activated,
while the other jaws 24 and 25 stay retracted.
Continued rotation of the cam ring 76 in the counterclockwise
direction, as the invention is illustrated, brings the inclined
portions 83 and 84 of the grooves 81 and 82 to bear against the
rollers 94 and 95, as shown in FIG. 18. When this occurs, the
surfaces 83 and 84 cam the rollers 94 and 95 inwardly with respect
to the transverse slot 49 in the carrier 43. This, in turn, forces
the jaws 24 and 25 inwardly toward the contact 11.
Further counterclockwise movement of the cam ring 76 brings it to
the position of FIG. 19, where the rollers 94 and 95 are forced
nearly all the way out of the grooves 81 and 82. This causes the
arcuate surfaces 26 and 27 of the jaws 24 and 25 to engage and
compress the sides of the contact barrel end 12. During this time,
the outer ridges 88 and 89 of the other jaws 20 and 21 slide along
the cylindrical inner surface 77 of the cam ring 76. This maintains
the jaws 20 and 21 in their inner position, where they are held as
the jaws 24 and 25 complete the crimping operation.
The handles 40 and 41 then are released and the parts of the
crimping tool are returned to their original positions. A
telescoping link 121 interconnects the handles 40 and 41 and
contains a compression spring so that it biases the handles to
their separated position. The link 121 also includes a ratchet
which will not allow the handles to release until they have been
advanced a full stroke relatively toward each other, to assure that
a complete crimping operation is accomplished. This type of link is
conventional in hand crimping tools.
The stop 120 is adjustable to vary the amount of rotation permitted
the plate 98, its arm 101 and, therefore, the carrier 42. This, in
turn, governs the total travel of the curved jaws 24 and 25. The
stop 120 is mounted on a pin 122 and is rotatable by a knob 123
relative to the handle 41. The stop 120 includes a series of flat
surfaces 124 on its exterior which are at different distances from
the axis of the pin 122. Rotation of the stop 120, therefore, can
place a selected flat surface 124 adjacent the arm 101.
When a particular contact size and configuration requires maximum
movement of the jaws 24 and 25, the surface 124 farthest from the
axis of the pin 122 is positioned adjacent the arm 101. In the
example shown in FIG. 8, this is the surface at the left-hand
portion of stop 120. This allows only minimal rotation of the arm
101, after which it and, therefore, the carrier 42 are prevented
from movement. Consequently, during a maximum portion of the stroke
of the handle 40, the cam ring 76 moves relative to the carrier 42.
This greater relative rotation of the cam ring causes the rollers
94 and 95 to be forced farther out of the grooves 81 and 82 by the
time the stroke of the cam ring is completed. The inclined surfaces
83 and 84 of the grooves 81 and 82, therefore, drive the rollers 94
and 95 and, hence, the jaws 24 and 25 inwardly a maximum distance.
This provides the greatest degree of compression on the barrel end
12 of the contact 11.
On the other hand, if the stop 120 is positioned so that the
surface 124 closest to the axis of the pin 122 is located adjacent
the arm 101, there will be the greatest amount of movement of the
carrier 43 with the cam ring 76. The resulting lesser amount of
relative rotation causes the rollers 94 and 95 to move only part
way down the sloping cam surfaces 83 and 84. This cams the rollers
94 and 95 inwardly a minimum distance and produces less compression
of the barrel and 12 of the contact.
A dial 124 and index marking 125 are provided on the exterior of
the handle portion 103 so that appropriate adjustment of the stop
120 is readily effected.
The foregoing detailed description is to be clearly understood as
given by way of illustration and example only, the spirit and scope
of this invention being limited solely by the appended claims.
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