Crimping diameter adjusting valve

A crimping machine for crimping a metal end fitting onto a flexible hose includes a stationary socket, a crimping die arranged in the socket for axial movement, and a hydraulic actuator. A valve member is provided in a fluid flow passage leading from a pump to the actuator. The distance between the valve member and a piston of the actuator is precisely controlled to control the axial movement of the crimping die relative to the socket.

BACKGROUND AND SUMMARY OF THE INVENTION 
A wide variety of crimping machines for radially deforming a metal end 
fitting to permanently secure the end fitting onto a flexible hose has 
been provided by the prior art. One such prior art crimping machine is 
disclosed in U.S. Pat. No. 3,742,754. This prior art machine uses a 
hydraulic ram or piston which acts on a gaging plate to push a multiple 
segment crimping die into a conical socket. The gaging plate shown in this 
prior art patent is reversible to change the amount of axial movement of 
the multiple segment die relative to its associated socket. 
The present invention departs from prior art crimping machines and provides 
a crimping machine which includes a stationary socket and a crimping die 
which is moved axially relative to the socket to crimp a workpiece. A 
hydraulic actuator for moving the crimping die relative to the socket 
includes a cylinder, an end plate closing one end of the cylinder, and a 
piston slidable within the cylinder. The cylinder and end plate and piston 
cooperatively define a variable volume pressure chamber. 
A hydraulic pump provides a source of fluid power for the crimping machine, 
and a passage in the end plate connects the pump to the pressure chamber. 
A valve member in the passage is movable between an open position opening 
the passage and a closed position closing the passage. 
A mechanical connecting rod is rigidly secured at one end to the valve 
member and is adjustably secured at the other end to the piston. By this 
arrangement, movement of the piston in a direction away from the end plate 
moves the valve member toward its closed position to close the passage. 
The connecting rod is threadably secured to the piston so that rotation of 
the connecting rod changes the distance between the valve member and the 
piston. This changes the position of the piston at which advancing 
movement of the piston is terminated by closing fluid flow from the pump 
through the passage to the pressure chamber. 
A valve stem is provided for rotatably adjusting the connecting rod 
relative to the piston. A pivotal connection is provided between the stem 
and the valve member, so that the valve member will properly seat in the 
passage even if the stem is not precisely aligned with the valve member 
and connecting member. A one way check valve provided in the valving 
member permits reduction of fluid pressure in the pressure chamber when 
the piston is to be retracted.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring now to the drawings in greater detail, FIG. 1 shows a crimping 
machine which includes a bed plate 11, a lower cylinder end plate 12, and 
an upper cylinder end plate 14. The plates 11, 12 and 14 are each 
generally flat rectangular plates. Four tension rods 15 are disposed at 
the four corners of the rectangular plates 11, 12 and 14. The tension rods 
15 are each stepped to provide a larger diameter portion between the bed 
plate 11 and the lower end plate 12 and a smaller diameter portion between 
the lower end plate 12 and the upper end plate 14. Alternatively, the rods 
15 may be of uniform diameter and may be fitted with a suitable collar 
between the bed plate 11 and the lower end plate 12 to maintain the proper 
spacing therebetween. 
A cylinder 19 is disposed between the end plates 12 and 14. An elastomeric 
seal 20 prevents fluid leakage between the cylinder 19 and the upper end 
plate 14. A cylindrical ram or piston 21 is slidably disposed in the 
cylinder 19. Fluid leakage between the piston 21 and cylinder 19 is 
prevented by an elastomeric seal 22. The upper end plate 14 and cylinder 
19 and ram 21 cooperatively define a variable volume fluid pressure 
chamber 23. 
An inverted cup shaped cylindrical pusher member 24 is secured to the 
bottom end of the piston 21 by a suitable bolt 25. The pusher member 24 is 
preferably provided with a longitudinal slot (not shown) extending 
upwardly from its open end to permit a fitting which is to be crimped to 
slide on the bed plate 11 laterally into and out of the pusher member 24. 
This slot in the side wall of the pusher member 24 is disclosed in U.S. 
Pat. No. 3,742,754. A coil spring 26 acts between the lower end plate 12 
and the piston 21 to return the piston 21 to a fully retracted position 
shown in FIG. 1 when pressure is released in the chamber 23. 
Still referring to FIG. 1, the bed plate 11 is provided with a slot 29 
extending laterally rearwardly from the front edge of the bed plate 11. 
This arrangement of the slot 29 is also shown in the above referenced U.S. 
Pat. No. 3,742,754. A conical socket 30 is slidably disposed on the bed 
plate 11 and is axially aligned with the piston 21 and the pusher member 
24 and slot 29. 
A crimping die 31 having a conical outer peripheral surface 32 is received 
in the socket 30. The crimping die 31, as disclosed in U.S. Pat. No. 
3,750,452, includes a plurality of die segments 33 which are biased to a 
free radially outward position shown in FIG. 1 by a resilient spacer 
material 34. A removable flat annular ring 27 rests on top of the crimping 
die 31 to transmit force between the pusher member 24 and each of the 
segments 33 of the crimping die 31. 
A metal hose end fitting 35 is assemblied on one end of a flexible hose 36. 
The end fitting 35 is placed in the crimping die 31 in the manner shown in 
FIG. 1 when the end fitting 35 is to be radially inwardly deformed or 
crimped to fasten the end fitting 35 onto the end of the hose 36. 
Still referring to FIG. 1, a pump 40 driven by an electric motor 41 is 
arranged to supply fluid from a reservoir 42 to a valve 43. A hydraulic 
line 44 connects the valve 43 to a fluid passage leading to the chamber 23 
as described below. 
Referring now to FIG. 2, a fluid passage 48 extends axially completely 
through the upper end plate 14 to supply fluid to and exhaust fluid from 
the chamber 23. A replaceable valve seat 49 is secured in the passage 48 
by a housing 50 which is threadably secured in the passage 48. 
A valve member 54 is disposed in the passage 48 for movement toward and 
away from the valve seat 49 to close and open the passage 48. A connecting 
rod or pin 55 is formed integrally with the valve member 54 and extends 
downwardly from the valve member 54 to a threaded lower portion which is 
threadably received in a threaded hole 56 extending from the top surface 
of the piston 21. By this arrangement, the valve member 54 is secured to 
the piston 21 for axial reciprocating movement with the piston 21 under 
all conditions. 
A cylindrical valve stem 57 extends upwardly from the valve member 54 
through the passage 48. The lower end of the valve stem 57 is pivotally 
connected to the valve member 54 by a pin 58 which extends through aligned 
holes in the valve member 54 and valve stem 57. The top of the passage 48 
in the housing 50 is provided with an elastomeric O-ring seal 59 which 
engages the top of the valve stem 57 to prevent fluid leakage between the 
housing 50 and the valve stem 57. 
An inverted cup-shaped thimble 60 is secured to the top of the valve stem 
57 by a set screw 61. By this arrangement, rotation of the thimble 60 
rotates the valve stem 57 to thread the connecting pin 55 into or out of 
the threaded hole 56. 
As best shown in FIG. 3, in which the thimble 60 is removed from the 
housing 50 for clarity, the bottom peripheral edge 62 of the thimble 60 is 
marked with the numbers 0 through 9 at evenly spaced intervals. The outer 
surface of the top portion of the housing 50 is provided with a scale 
which is divided into 10 equal parts, with each part having a length equal 
to the axial movement of the thimble 60 which occurs when the thimble 60 
is rotated one full turn. By this arrangement, when the piston 21 is 
retracted, the axial distance between the valve member 54 and the piston 
21 can be precisely adjusted by turning the thimble 60 to a predetermined 
numbered position on the scales which are provided on the housing 50 and 
thimble 60. 
A shoulder 63 on the valve stem 57 engages an axially aligned shoulder on 
the housing 50 when the valve stem 57 is rotated in a direction to thread 
the connecting pin 55 out of the threaded hole 56. This limits the maximum 
distance that can be provided between the valve member 54 and the piston 
21 when the piston 21 is in its retracted position to limit the maximum 
stroke of the piston 21. The depth of the thread in the threaded hole 56 
limits the threading of the connecting pin 55 into the threaded hole 56 to 
limit the minimum distance between the valve member 54 and the piston 21 
when the piston 21 is retracted. This limits the minimum stroke of the 
piston 21. 
A T-shaped return flow passage 64 extends axially and radially through the 
valve member 54. The return flow passage 64 has a conical valve seat which 
cooperates with a ball 65 to provide a one way return flow check valve. 
When the piston 21 is at the end of its stroke so that the valve member 54 
engages the valve seat 49 to close the passage 48 and the piston is to be 
retracted, a decrease in fluid pressure on the pump side of the valve 
member 54 permits the ball 65 to be unseated in the return flow passage 64 
to permit initial return flow of fluid from the chamber 23. After a very 
small volume of fluid passes through the return flow passage 64, the valve 
member 54 separates from the valve seat 49 to permit further return flow 
of fluid from the chamber 23. 
As may be seen by reference to FIG. 1, the amount of radial deformation of 
the end fitting 35 is determined by the distance that the crimping die 31 
is pushed into the conical socket 30. This distance may not be the same 
for different types of end fittings which are to be crimped by any one 
crimping die. Additionally, when different crimping dies are used for 
different sizes of hose and end fittings, this distance also changes. 
According to the present invention, this distance which the crimping die 
31 is pushed into the socket 30 is determined by changing the stroke of 
the piston 21 and pusher member 24. 
Prior to the crimping of the end fitting 35, and while the piston 21 is in 
the fully retracted position shown in FIG. 1, the thimble 60 is rotated to 
a predetermined position relative to the housing 50 as indicated by the 
scales on the outer surface of the housing 50 and on the bottom peripheral 
edge of the thimble 60. For any particular type and size of end fitting 
that is to be crimped, the proper position of the thimble 60 may be read 
from a chart (not shown) secured at a convenient location on the crimping 
machine. Rotating the thimble 60 to this predetermined setting relative to 
the housing 50 positions the valve member 54 a predetermined position from 
the valve seat 49. This distance between the conical valving surface of 
the valve member 54 and the mating conical valving surface of the valve 
seat 49 determines the stroke of the piston 21. 
After setting the thimble 60 to the proper number, the valve 43 is moved to 
the right and the motor 41 is actuated to operate the pump 40. The pump 40 
supplies high pressure fluid through the line 44 to the passage 48 leading 
to the pressure chamber 23. Because the valve member 54 is spaced from the 
valve seat 49, this high pressure fluid flows into the pressure chamber 23 
and advances the piston 21 axially downwardly against the force of the 
return spring 26. When the bottom edge of the pusher member 24 engages the 
top surface of the crimping die 31, the crimping die 31 begins to move 
axially downwardly into the conical socket 30. This axial advancing of the 
crimping die 31 into the conical socket 30 displaces the several segments 
33 of the crimping die 31 radially inwardly to crimp the hose end fitting 
35 onto the flexible hose 36. 
This advancing movement of the piston 21 pulls the valve member 54 toward 
the valve seat 49 by operation of the connecting pin 55. When the valve 
member 54 engages the valve seat 49, the passage 48 extending into the 
pressure chamber 23 is closed so that advancing movement of the piston 21 
is terminated. Any further increase in fluid pressure on the pump side of 
the valve member 54 acts on the valve member 54 in a direction to urge the 
valve member 54 against the valve seat 49. 
When this occurs and the relief pressure of the pump is reached, the 
operator moves the control valve 43 to the left and shuts off the electric 
motor 41. This connects the upper side of the valve member 54 to the 
reservoir 42 through the line 44. As pressure on the upper side of the 
valve member 54 decreases to a pressure less than the pressure in the 
chamber 23, the ball 65 is unseated to permit fluid flow from the chamber 
23 through the return flow passage 64. As the fluid in the chamber 23 
returns to the reservoir 42 through the line 44 and the valve 43, the 
piston return spring 26 moves the piston 21 back toward its retracted 
position. Because the volume of fluid in the chamber 23 is quite large and 
the cross sectional area between the valve member 54 and the valve seat 49 
is quite small upon initial separation thereof, a high velocity fluid flow 
between the valve seat 49 and the valve member 54 washes any impurities 
from the valve seat 49 and valve member 54. 
After the piston 21 is fully retracted to the position shown in FIG. 1, the 
end fitting 35 is removed from the crimping die 31. The machine is then 
ready to receive the next workpiece (not shown) and to crimp the next 
workpiece in the manner described above.