Crimp die with positive connector stop

Crimping dies for hydraulic compression tools for electrical connectors and the like in which one of the dies in a matching set is provided with means for engaging and stopping a connector workpiece in proper position for crimping in the die jaw.

BACKGROUND OF THE INVENTION 
The present invention relates to crimp dies for hydraulic compression tools 
for affixing electrical connectors to conductor wires. 
Hydraulic tools for crimping connectors such as Burndy corporation HYPRESS 
models Y35, Y35-2 and Y750 utilize crimping dies for mechanically securing 
a connector to a conductor wire. These tools include a diehead subassembly 
fitted to operating handles which develop substantial crimping force for 
making the connection. 
When securing a connector such as a terminal connector to a conductor, it 
is necessary to accurately locate the connector in the crimping dies so 
that a secure connection is made. 
SUMMARY OF THE INVENTION 
The present invention is directed to crimping dies for hydraulic 
compression tools and more particularly to providing means for positioning 
a workpiece connector when forming a connection with a conductor. The 
invention provides a die stop in the vicinity of the die crimping groove 
for engaging a workpiece connector so as to precisely locate the crimping 
portion of the connector. In this way, the crimping dies produce a firm 
and permanent mechanical connection between connector and conductor. 
In a preferred form of the invention, a hydraulic compression tool is 
provided with a set of crimping dies normally referred to as movable and 
stationary die members. A die stop is formed into the body of the 
stationary die a predetermined distance from the crimp groove of the die 
set. The die stop is also aligned with the crimp groove so as to engage 
and position the connector in correct position within the die crimp 
groove. In this way the operator is able to quickly and accurately form 
connections. 
OBJECTS OF THE INVENTION 
It is an object of the invention to provide a die stop for positioning 
workpiece connectors in crimping dies. 
It is an object of the invention to provide a die stop formed integral with 
the stationary die of a die set for engaging a connector so as to properly 
position the connector in the crimping groove whereby a secure connection 
is made between connector and conductor. 
Other and further objects of the invention will occur to one skilled in the 
art with an understanding of the following detailed description of the 
invention or upon employment of the invention in practice.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to the drawing and particularly to FIG. 1, the hydraulic 
crimping tool 10 according to the invention comprises several major 
components including a C-shaped die head 12, a pump housing 14, and 
operating handles 16. 
The die head assembly includes a unitary C-shaped head 12 preferably forged 
integral defining a die cavity 18 between a fixed upper jaw 20 and a 
moveable lower jaw 22. The upper jaw is in the form of a crescent and 
receives a U-shaped die 24 supported by spaced ridges 26 and retained by a 
pin 28 and cooperating release shaft 30. The die 24 slips transversely 
into position in the upper jaw crescent. The lower jaw 22 is also in the 
form of a crescent at the upper surface of a piston ram 32 receiving a 
lower U-shaped die 24 between spaced supporting ridges and being retained 
by a lock pin 34. When using the hydraulic crimping tool, the upper and 
lower dies engage a connector workpiece 36 (FIG. 5) crimping it into place 
with substantial crimping force developed by the tool. 
The embodiment of the invention shown in FIGS. 2 and 3 comprises a die set 
of upper and lower dies 24. The upper die is stationary and is referred to 
herein as the stationary die whereas the lower die is moveable being 
affixed to the movable power ram. Both dies in the set are identical 
except for the placement of a die stop 54 on the stationary die. 
Accordingly, the specification proceeds with an illustration and 
description of the stationary member of the die set of each embodiment of 
the invention. 
The stationary die 24 in FIGS. 2 and 3 is generally crescent or U-shaped 
and includes a curved spine 40 of generally rectangular cross-section 
terminating in spaced die faces 42 lying in a common plane. The outer 
margins of the spine are notched at 44 to define retaining edges by which 
the dies are retained in the C-shaped die head. The die further includes 
an integral die plate 46 extending across the inner face 48 of the spine. 
The die plate is centered along the inner face and occupies approximately 
one-third of the width of the inner face (as best shown in FIG. 2) thereby 
defining laterally extending shoulders 50 along the inner face on either 
side of the die plate. A crimp groove 52 is formed in the surface of the 
die plate of both the movable and stationary dies and represents the 
contact surface for engaging a connector workpice for crimping. 
In accordance with the invention, the die set includes means 54 for 
positioning a connector accurately in the crimp groove for crimp 
formation. A connector 36 is shown in FIG. 5 and includes a hollow sleeve 
58 for receiving a conductor 60 and an integral plate 62 for connection to 
a terminal through a plate opening 64. An inclined shoulder 65 between the 
sleeve and plate provides a contact surface for positioning the connector 
in a crimping groove. The overlapping area A of contact between connector 
sleeve and conductor occurs over a limited portion of the connector. For 
example the area of contact A of a typical connector occurs in a one-half 
inch length of the connector sleeve. In order to achieve a proper 
mechanical joining of connector and conductor, it is necessary to position 
the crimp groove accurately on the connector sleeve. To accomplish this 
end, a die stop 54 is located on the inner face 48 of the stationary die 
to provide positive engagement and positioning of the connector sleeve in 
the crimp groove as shown in dash lines in FIG. 3. In a preferred form, 
the die stop 54 comprises a threaded cylinder 66 projecting from a 
matching threaded bore 68 through one of the lateral shoulders 50 of the 
die. The die stop terminates in a pin 70 extending longitudinally from the 
cylinder with the pin having a cylindrical outer surface. The pin may also 
have a polygonal cross-section defined by three or more flat outer 
surfaces for engagement by an adjusting tool for positioning the pin 
relative to the crimp groove. As shown in FIG. 3, the pin engages the 
inclined shoulder 65 of a connector so as to position the connector within 
the crimping dies such that the dies accurately crimp the connector sleeve 
forming a proper mechanical bond with the conductor. When the crimp is 
complete, the hydraulic force is released and the dies open to allow 
removal of the tool from the newly formed connection. 
A modified embodiment of the invention is shown in FIGS. 4, and 6-10 and 
comprises a die set with stationary die component illustrated and 
described. The die includes a main body or spine portion 40 with depending 
front and rear ears 72 for securing the die components to a hydraulic 
crimping tool. The central portion of the body or spine is recessed along 
inner face 48 to define a die plate 46 located across the recess and 
occupying approximately one-third of the width of the recess between the 
front 74 and rear 76 sides of the main body. A crimp groove 52 is formed 
in the die plate for receiving and crimping a connector sleeve in 
cooperation with a mating movable die having a similar crimp groove. In 
this embodiment of the invention, the means 54 for positioning the 
connector is in the form of a die stop tab 78. The stop tab is located 
adjacent the crimp groove for positioning a connector in the dies. The 
stop tab 78 has a box-like shape and is machined from the body stock by 
the formation of a recess on one side of the crimp groove with the tab 
projecting upward from the recess in axial alignment with the groove. The 
positioning of a connector 36 by the stop tab 78 is shown in FIG. 7. 
A further modification of the invention is shown in FIGS. 11-15 and 
comprises a stationary die 24 substantially similar to the stationary die 
of FIGS. 4, and 6-10. The die includes a main body or spine portion 40 
with depending front and rear ears 72 for securing the die components to a 
hydraulic crimping tool. The central portion of the body is recessed along 
inner face 48 to define a die plate 46 located across the recess and 
occupying approximately one-third of the width of the recess between the 
sides of the main body. A crimp groove 52 is formed in the die plate for 
receiving and crimping a connector sleeve in cooperation with a mating 
movable die. In this form of the invention, the means 54 for positioning a 
connector is in the form of a die stop edge 80 formed in the recess 48 
behind the die plate. The die stop edge extends across the die recess in 
parallel relationship to the die plate 46. The die stop edge engages the 
inclined shoulder 65 of a connector 36 as shown in FIG. 13 thereby 
positioning the connector sleeve accurately in the crimp groove. 
For ease of reference in summarizing the invention, the matching dies 24 of 
each embodiment of the invention comprise the following components. Each 
die set includes a matched pair of stationary and movable dies 24 with 
each die having a body portion or spine 40. The body portion is defined by 
a U-shaped outer wall 41, substantially parallel front 74 and rear walls 
76, a top wall including die faces 42, an arcuate recess or inner face 48 
extending through the body portion and through the front and rear walls 
and thereby defining arcuate side walls 43 whose inner margins are the 
arcuate recess 48 and outer margins the U-shaped outer wall 41. A die 
plate 46 extends across the recess between the side walls with a crimping 
groove 52 in the die plate. The notches 44 of the embodiment of FIGS. 1-2, 
and the ears 72 of the embodiments of FIGS. 4, and 6-15 are for securing 
each die to a hydraulic compression tool with the die recesses in 
confronting relation and with the crimping grooves cooperating to engage 
and crimp a connector. Each embodiment of the invention is provided with 
means 54 forming part of one of the dies projecting from the arcuate 
recess 48 adjacent the crimping groove 52 of said one die for engaging and 
stopping a connector 36 in proper position for crimping by the tool. The 
engaging and stopping means include the stop pin 70 of FIGS. 1-2, the stop 
tab 78 of FIGS. 4, and 6-10, and the stop edge 80 of FIGS. 11-15. 
In this way the invention promotes secure mechanical bonding between 
connector and conductor when the two are crimped with a hydraulic tool 
using a die set according to the invention.