U.S. patent application number 11/031192 was filed with the patent office on 2005-06-09 for chain cutter.
This patent application is currently assigned to Vindee Industries, Inc.. Invention is credited to Bakker, Douglas A., McCarthy, Robert E., Verre, John L..
Application Number | 20050120768 11/031192 |
Document ID | / |
Family ID | 34436010 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050120768 |
Kind Code |
A1 |
McCarthy, Robert E. ; et
al. |
June 9, 2005 |
Chain cutter
Abstract
A compact chain cutting apparatus for automatically shearing and
opening a chain link of a selected thickness in one operation is
disclosed. The apparatus includes a housing, a first shearing
member, a second shearing member, and an electro-hydraulic actuator
system. The first shearing member is mounted to the housing. The
second shearing member is pivotally mounted to the housing for
movement to exert, in cooperation with the first shearing member,
shearing and bending forces upon the chain link. The
electro-hydraulic actuator system cooperates with the second
shearing member to move automatically the second shearing member to
shear and to bend the chain link, thereby defining an opening in
the chain link greater than the thickness of the link.
Inventors: |
McCarthy, Robert E.; (Crete,
IL) ; Verre, John L.; (Orland Park, IL) ;
Bakker, Douglas A.; (Crown Point, IN) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
TWO PRUDENTIAL PLAZA, SUITE 4900
180 NORTH STETSON AVENUE
CHICAGO
IL
60601-6780
US
|
Assignee: |
Vindee Industries, Inc.
Frankfort
IL
|
Family ID: |
34436010 |
Appl. No.: |
11/031192 |
Filed: |
January 7, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11031192 |
Jan 7, 2005 |
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10404462 |
Apr 1, 2003 |
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6880378 |
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10404462 |
Apr 1, 2003 |
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09909126 |
Jul 18, 2001 |
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Current U.S.
Class: |
72/326 |
Current CPC
Class: |
B23D 27/06 20130101;
Y10T 83/8809 20150401; B21L 21/00 20130101; Y10T 83/9396 20150401;
B23D 17/06 20130101 |
Class at
Publication: |
072/326 |
International
Class: |
B21L 021/00 |
Claims
1. An apparatus for automatically shearing and bending a chain
link, the chain link having a selected thickness, the apparatus
comprising: a first shearing member, the first shearing member
having a shearing surface defining a shearing plane and terminating
in a first shearing edge, the first shearing member including a
jaw, the jaw having a primary bearing surface to exert shearing and
bending forces upon the chain link and a secondary bearing surface
for preventing unrestrained twisting during the shearing and
bending operations, the jaw defining an opening, the opening
configured to accommodate the thickness of the chain link; a second
shearing member, the second shearing member having a shearing
surface disposed substantially parallel to the shearing plane and
terminating in a second shearing edge, the second shearing member
including a primary bearing surface to exert shearing and bending
forces upon the chain link, the second shearing member arranged
with the first shearing member for relative shearing action along
the shearing plane between the shearing edges and the primary
bearing surfaces; and an electro-hydraulic actuator system
cooperating with the second shearing member, the actuator system
selectively operable to move automatically the primary bearing
surface and the second shearing edge of the second shearing member
toward and beyond the primary bearing surface and the first
shearing edge of the first shearing member to shear the chain link
along the shearing plane, thereby defining a pair of severed ends
in the chain link, and to bend the severed ends apart while the
chain link is restrained against excessive twisting by the
secondary bearing surface of the first shearing member, thereby
defining an opening between the severed ends of the chain link
greater than the thickness of the chain link, the actuator system
being electrically operated and requiring no manual actuation force
input.
2. The apparatus as set forth in claim 1 wherein the shearing
surface and the primary bearing surface of the second shearing
member define a rake angle that is slightly less than 90.degree.
where the primary bearing surface and the shearing surface meet to
form the first shearing edge.
3. The apparatus as set forth in claim 2 wherein the rake angle is
about 89.degree..
4. The apparatus as set forth in claim 1 wherein the second
shearing member includes a jaw, the jaw having a nip surface and
the primary bearing surface, the nip surface and the primary
bearing surface defining a jaw angle that is between about
85.degree. and about 95.degree..
5. The apparatus as set forth in claim 4 wherein the jaw angle is
about 90.degree..
6. The apparatus as set forth in claim 1 wherein the second
shearing member includes first and second holes which define a
lever arm axis, the primary bearing surface and the lever arm axis
defining an angle that is between about 22.5.degree. and about
27.5.degree..
7. The apparatus as set forth in claim 6 wherein the first cutting
edge angle is about 25.degree..
8-10. (canceled)
11. The apparatus as set forth in claim 1 wherein the primary
bearing surface of the second shearing member faces in the opposite
direction from the primary bearing surface of the first shearing
member.
12. The apparatus as set forth in claim 1 wherein the
electro-hydraulic actuator system is electrically operated.
13. The apparatus as set forth in claim 1 wherein the
electro-hydraulic actuator system is hydraulically actuated.
14. The apparatus as set forth in claim 12 wherein the
electro-hydraulic actuator system is hydraulically actuated.
15. The apparatus as set forth in claim 14 wherein the
electro-hydraulic actuator system includes a hydraulic cylinder and
an electric motor for selectively driving the hydraulic
cylinder.
16. An apparatus for automatically shearing and bending a chain
link, the chain link including a selected thickness, the apparatus
comprising: a housing; a first shearing member mounted to the
housing; a second shearing member pivotally mounted to the housing
for movement to exert, in cooperation with the first shearing
member, shearing and bending forces upon the chain link; and an
electro-hydraulic actuator system cooperating with the second
shearing member to move automatically the second shearing member to
shear and to bend the chain link, thereby defining an opening in
the chain link greater than the thickness of the link.
17. An apparatus for automatically shearing and bending a chain
link, the chain link including a selected thickness, the apparatus
comprising: a housing; a first shearing member mounted to the
housing; a second shearing member, the second shearing member
pivotally mounted to the housing for movement substantially
parallel to the shearing plane, the second shearing member arranged
with the first shearing member for relative shearing action between
the first and second shearing members; and an electro-hydraulic
actuator system cooperating with the second shearing member, the
actuator system selectively operable to move automatically the
second shearing member relative to the first shearing member to
shear the chain link and to bend the chain link to define an
opening in the chain link greater than the thickness of the chain
link, the actuator system requiring no manual actuation force
input, the actuator system including a hydraulic cylinder, a pump,
and a motor, the hydraulic cylinder mounted to the second shearing
member for movement thereof, the pump fluidly connected to the
hydraulic cylinder for driving the hydraulic cylinder, and the
motor operatively connected to the pump for selectively driving the
pump.
18. The apparatus as set forth in claim 17 wherein the actuator
system further comprises a reservoir, the hydraulic cylinder having
a base and a driving rod with a distal end, the base pivotally
mounted to the housing, the distal end of the rod mounted to the
second shearing member for moving the second shearing member, the
distal end of the rod mounted to the second shearing member for
moving the second shearing member, the reservoir having a quantity
of hydraulic fluid, the pump fluidly connected to the reservoir for
drawing the hydraulic fluid from the reservoir and pumping the
hydraulic fluid under pressure to the hydraulic cylinder.
19. The apparatus as set forth in claim 18 wherein the actuator
system includes a spring for biasing the second shearing member to
an open position wherein the first and second shearing edges are
disposed apart from each other.
20. The apparatus as set forth in claim 19 wherein the spring
includes a pair of ends, the ends being mounted to the base of the
cylinder and the distal end of the rod.
21. The apparatus as set forth in claim 18 wherein the second
shearing member is in the form of a lever and includes a pivot end,
the chain cutting apparatus includes a rod extending through the
second shearing member and supported at each end by the housing,
the rod being a fulcrum for the second shearing member, the pivot
end and the rod defining a lever arm of the second shearing member,
and the driving rod of the hydraulic cylinder operates upon the
lever arm for producing the shearing action between the first and
second shearing members.
22-27. (canceled)
28. The apparatus as set forth in claim 27 wherein the second
shearing member is driven by the hydraulic cylinder at a speed of
about 0.096 inches per second.
29. The apparatus as set forth in claim 17 wherein the actuator
system further comprises a dump valve for resetting the actuator
system such that the second shearing member is in an open
position.
30-32. (canceled)
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a chain cutting
apparatus, and more particularly to an automatically operated,
electro-hydraulically actuated apparatus for cutting and opening
chain links.
BACKGROUND OF THE INVENTION
[0002] In retail establishments selling chain and in light
manufacturing facilities, chain is generally cut by either sawing
through the chain links or by using a cold forming pincher-type
tool commonly called a "bolt cutter." While these techniques are
adequate for cutting small gauge chains, the same techniques raise
a number of practical problems in cutting larger gauge chains.
[0003] In the case of sawing through a link, the most serious
problem arises from the necessity to support the chain link rigidly
in a vice or other clamping apparatus while a hack saw is employed
to saw through the link at a point along its circumference. If only
one cut is made through the link, some means of bending the link
must be employed in order to create an opening between the severed
ends large enough to allow the cut link to be disengaged from the
connecting links. This additional operation necessarily involves
the use of a second tool, whether it be a lever-type instrument to
pry open the link or an impact-type instrument to hammer the link
open. The bending operation can be eliminated by sawing through the
link at a second point, thereby bisecting the link. This second
cutting operation is time consuming and difficult when dealing with
heavy gauge chains.
[0004] When a bolt cutter or similar tool is used, again it is
necessary either to cut the link in two places or employ
supplemental means to bend the cut link open. Another problem
arises because of the difficulty in holding the tool; namely, the
risk that the cutting edges will be abused.
[0005] Moreover, sawing cable or wire rope to cut it causes fraying
at the cut ends. Cutting cable or wire rope by cold forming
techniques is only effective if the working edges of the "bolt
cutter" are maintained adequately to sever the individual strands
of the cable. It is often difficult to so maintain the edges when,
as a result of economy, the same tool is used on chain, bolts,
cable, and other like materials.
[0006] A manually operated, hydraulically actuated apparatus for
both cutting and opening chain links, for example, as shown and
described in U.S. Pat. No. 3,996,782, has been used to solve some
of the problems of the prior art. Although such a device has many
desirable features and advantages, there remain certain problems
with this cutter.
[0007] For example, the manual chain cutter using a manual pump
jacks is prone to fluid leakage, labor intensive to operate, slow
and under-powered for cutting certain sizes of chain link. The
seals in the apparatus have a tendency to wear out and allow fluid
leakage to occur. In operation, the apparatus typically requires
priming before the apparatus can be used to cut. When cutting a
chain link of larger gauge, the pump jack often must be pumped over
fifty times in order to successfully cut and open the chain link.
Furthermore, maintaining the manual pump jacks can be
cumbersome.
[0008] In view of the foregoing, there exist various needs in the
art. One such need is for a compact, durable chain cutter which
provides uniform, consistent speed and power during cutting. A
further need exists for a chain cutter that is fast and easy to
operate. Additionally, it would be desirable for the chain cutter
to be safe to use and operable only by authorized personnel.
SUMMARY OF THE INVENTION
[0009] The present invention addresses the foregoing and other
needs by providing an automatically-operated,
hydraulically-actuated apparatus for cutting and opening chain
links. In one aspect of the present invention, there is provided an
automatic apparatus for shearing and bending a chain link of a
selected thickness. The apparatus includes a housing. A first
shearing member is mounted to the housing. A second shearing member
is pivotally mounted to the housing for movement to exert, in
cooperation with the first shearing member, shearing and bending
forces upon the chain link. An electro-hydraulic actuator system is
provided to move automatically the second shearing member to shear
and to bend the chain link, thereby defining an opening in the
chain link greater than the thickness of the link.
[0010] The first shearing member has a shearing surface defining a
shearing plane and terminating in a first shearing edge. The first
shearing member includes a jaw. The jaw has a primary bearing
surface to exert shearing and bending forces upon the chain link
and a secondary bearing surface for preventing unrestrained
twisting during the shearing and bending operations. The jaw
defines an opening configured to accommodate the thickness of the
chain link.
[0011] The second shearing member has a shearing surface disposed
substantially parallel to the shearing plane and terminating in a
second shearing edge. The second shearing member includes a primary
bearing surface to exert shearing and bending forces upon the chain
link. The second shearing member is arranged with the first
shearing member for relative shearing action along the shearing
plane between the primary bearing surfaces and the shearing
edges.
[0012] The electro-hydraulic actuator system requires no manual
actuation force input. The actuator system includes a hydraulic
cylinder, a pump, a reservoir, and an electric motor. The hydraulic
cylinder has a base and a driving rod with a distal end. The base
is pivotally mounted to the housing. The distal end of the rod is
mounted to the second shearing member for moving the second
shearing member. The pump is fluidly connected to the cylinder for
driving the cylinder. The reservoir has a quantity of hydraulic
fluid. The pump is fluidly connected to the reservoir for drawing
the hydraulic fluid from the reservoir and pumping the hydraulic
fluid under pressure to the hydraulic cylinder. The motor is
operatively connected to the pump for selectively driving the
pump.
[0013] Significantly, the actuator system requires no priming
before operation and moves the second shearing member smoothly and
consistently through a substantially uniform stroke at a steady
velocity.
[0014] Advantageously, the present invention provides an automated
apparatus for cutting and opening in a single operation a chain
link, thereby minimizing the time, energy, and equipment required.
Furthermore, the apparatus is capable of cutting not only chain but
also bolts, wire rope, and the like.
[0015] Advantageously, the present invention provides an automated
chain cutting apparatus which is compact, powerful enough to
operate on chain links of heavy--as well as light--gauge, and
composed of relatively inexpensive components, to fulfill the
cutting needs of retail establishments and light manufacturing
facilities.
[0016] By eliminating the need to cut the chain link by manual
exertion, the present invention can be used by a wide range of
users and requires very little physical exertion on the part of the
user. The chain cutting apparatus can be about six times as fast as
a prior art manual chain cutting apparatus in cutting a chain link.
Furthermore, no priming is required before operating the
apparatus.
[0017] As a further feature, the chain cutting apparatus can be
provided with a keyed switch for operating the motor.
Advantageously, the switch can be biased to an off position such
that the apparatus stops running once the operator releases the
key.
[0018] These and other objects and advantages, as well as
additional inventive features, of the present invention will become
apparent to one of ordinary skill in the art upon reading the
detailed description, in conjunction with the accompanying
drawings, provided herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a perspective view of an automatic chain cutting
apparatus according to the present invention;
[0020] FIG. 2 is a fragmentary front elevational view of the chain
cutting apparatus of FIG. 1 with a portion of the housing
removed;
[0021] FIG. 3 is a side elevational view of a first, stationary
shearing member of the chain cutting apparatus of FIG. 1;
[0022] FIG. 4 is an end elevational view of the stationary shearing
member of FIG. 3;
[0023] FIG. 5 is a side elevational view of a second, movable
shearing member of the chain cutting apparatus of FIG. 1;
[0024] FIG. 6 is a an end elevational view of the movable shearing
member of FIG. 5;
[0025] FIG. 7 is a fragmentary front elevational view as in FIG. 2
of a support system of the chain cutting apparatus of FIG. 1;
[0026] FIG. 8 is a side elevational view of a mounting block of the
chain cutting apparatus of FIG. 1
[0027] FIG. 9 is a fragmentary front elevational view of another
embodiment of a support system for a chain cutting apparatus
according to the present invention;
[0028] FIG. 10 is a side elevational view of a cutter keeper of the
support system of FIG. 8;
[0029] FIG. 11 is a front elevational view of the chain cutting
apparatus of FIG. 1 with a portion of the housing removed;
[0030] FIG. 12 is a cross-sectional view taken along line 12-12 of
FIG. 11 illustrating the operational parts of the chain cutting
apparatus; and
[0031] FIG. 13 is a diagrammatic general schematic view of an
ignition system for a motor of the chain cutting apparatus of FIG.
1.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0032] Shown in the drawings is an illustrative apparatus for
cutting and opening chain links and bolts and for severing steel
wire sold, for example, in hardware stores and material supply
depots. The illustrative chain cutter shown herein improves upon
and solves some of the drawbacks associated with the chain cutter
shown and described in U.S. Pat. No. 3,996,782, filed Jul. 17,
1975, and entitled "Chain Cutting Apparatus," which is incorporated
herein in its entirety by reference.
[0033] The instant apparatus employs a pair of shearing members
which interact to first shear a link of chain at a point along its
circumference and then to bend the link. The latter operation of
opening the link to permit the disengagement of the severed link is
more efficient, energy wise, than generating a second cut to
facilitate removal of the link. To allow a wide range of operators
to use the chain cutting apparatus, an automatic actuator system is
provided to operate automatically at least one of the shears to
perform the shearing and bending operations. The apparatus is
self-contained, lightweight, and, requiring only a 110
VAC-convenience outlet for its power source, readily transportable.
The small size of the apparatus, approximately one half cubic foot,
for example, contributes to its overall portability.
[0034] Turning now to the drawings, there is shown in FIG. 1 an
illustrative cutting apparatus 20 in accordance with the present
invention for automatically shearing and bending a chain link of a
selected thickness. The apparatus 20 includes a housing 22, a first
shearing member 24 mounted to the housing 22, a second shearing
member 26 pivotally mounted to the housing 22 for movement to
exert, in cooperation with the first shearing member 24, shearing
and bending forces upon the chain link, and an electro-hydraulic
actuator system 28 cooperating with the second shearing member 26
to move automatically the second shearing member 26 to shear and to
bend the chain link, thereby defining an opening in the chain link
greater than the thickness of the link.
[0035] The housing 22 supplies support for the first and second
shearing members 24, 26 and the actuator system. The housing 22
also serves to contain the mechanism in a compact, regularly shaped
package easily adapted to be mounted free standing on legs, or
attached directly to a point-of-purchase chain display unit.
Because of typical space limitations at the point of use, the size
of the housing is desirably very compact, for example,
approximately one half cubic foot. To provide a path for the
exchange of outside air with the cavity of the housing, a plurality
of vent holes can be disposed in the housing.
[0036] The shearing and bending portions 30, 32 of the first and
second shearing members 24, 26, respectively, a key 34 for
operating the apparatus 20, and a "dump" valve 36 for resetting the
actuator system 28 such that the second shearing member 26 is in an
open position project through a front cover 38 of the housing 22
for ready access by the operator.
[0037] The first and second shearing members 24, 26 are utilized
for the shearing and bending operations described above. The first
shearing member 24 is a stationary shearing member while the second
shearing member 26 is a movable shearing member in the form of a
pivotable lever.
[0038] Referring to FIGS. 2-4, the first shearing member 24
includes a shearing surface 40 that defines a shearing plane 41 and
terminates in a first shearing edge 42. The first shearing member
24 includes a generally U-shaped jaw 43. The jaw 43 has a primary
bearing surface 44 to exert shearing and bending forces upon the
chain link and a secondary bearing surface 45 for preventing
unrestrained twisting during the shearing and bending operations.
The primary bearing surface 44 and the secondary bearing surface 45
are disposed substantially parallel to each other. The jaw 43
defines an opening 46 configured to accommodate the thickness of
the chain link.
[0039] The secondary bearing surface 45 and a longitudinal axis 47
of the first shearing member define a jaw angle 48 that is
preferably between about 2.5.degree. and about 7.5.degree., and
more preferably about 5.degree.. The shearing surface 40 and the
primary bearing surface 44 of the first shearing member 24 define a
rake angle 49 where the primary bearing surface 44 and the shearing
surface 40 meet to form the first shearing edge 42 that is slightly
less than 90.degree., preferably between about 88.degree. and about
90.degree., even more preferably about 89.degree..
[0040] Referring to FIGS. 2 and 5, the second shearing member 26 is
shown. The second shearing member 26 includes a shearing surface 50
that is disposed substantially parallel to the shearing plane 41
and terminates in a second shearing edge 52. The second shearing
member includes a jaw 53 which has a primary bearing surface 54 and
a nip surface 55. The primary bearing surface 54 and the nip
surface 55 define a jaw angle 57 that is preferably between about
85.degree. and about 95.degree., and more preferably about
90.degree..
[0041] The second shearing member 26 includes the primary bearing
surface 54 to exert shearing and bending forces upon the chain
link. The primary bearing surface 54 is disposed at a first bearing
angle 58 relative to an upper edge 59 of the second shearing member
26 that is preferably between about 25.degree. and 35.degree., and
more preferably about 30.degree.. The primary bearing surface 54 is
preferably disposed at a second bearing angle 60 relative to a
front edge 61 of the second shearing member 26 that is preferably
between about 55.degree. and 65.degree., and even more preferably
about 60.degree..
[0042] The second shearing member includes a power transmission
hole 62 and a fulcrum hole 63. The transmission and fulcrum holes
62, 63 define a lever arm axis 64. The primary bearing surface 54
and the lever arm axis 64 define a third bearing angle 65 that is
preferably between about 2.5.degree. and 7.5.degree., and even more
preferably about 5.degree.. The upper edge 59 and the lever arm
axis 64 define a lever arm angle 66 that is preferably between
about 22.5.degree. and 27.5.degree., and even more preferably about
25.degree..
[0043] Referring to FIG. 6, in a preferred embodiment of the
invention, the shearing surface 50 and the primary bearing surface
54 of the second shearing member 26 define a rake angle 67 where
the primary bearing surface 54 and the shearing surface 50 meet to
form the second shearing edge 52 that is slightly less than
90.degree., preferably between about 88.degree. and about
90.degree., and even more preferably about 89.degree.. This
configuration serves to assure that, even after minor retouching of
the second shearing edge 52 should it become dull or chipped, the
shearing edge 52 will contact the material to be sheared prior to
contact by the primary bearing surface 54. This sequence of contact
facilitates clean shearing action.
[0044] It will be understood that other combinations of angles
within the tolerances shown are possible.
[0045] Referring to FIG. 2, the second shearing member 26 is
pivotally mounted to the housing 22 for movement substantially
parallel to the shearing plane 41 as indicated by a pair of arrows
68, 69 in FIG. 2. The second shearing member 26 is movable between
an open position and a range of cutting positions. The shearing
surface 50 of the second shearing member 26 is disposed
substantially parallel to the shearing plane 41 and terminates in
the second shearing edge 52. The primary bearing surface 54 of the
second shearing member 26 faces in the opposite direction from the
primary bearing surface 44 of the first shearing member 24. The
second shearing member 26 is cooperatively arranged with the first
shearing member 24 for relative shearing action therebetween. The
relative shearing action occurs along the shearing plane 41 between
the shearing edges 42, 52 and the primary bearing surfaces 44, 54
of the first and second shearing members 24, 26, respectively.
[0046] When the second shearing member 26 is in the open position,
the first and second shearing edges 42, 52 of the first and second
shearing members 24, 26, respectively, are disposed apart from each
other. The travel of the movable shearing member 26 from the open
position to a cutting position comprises a cut and open stroke.
[0047] In operation, the shearing members 24, 26 cooperate to shear
the chain link along the shearing plane 41. The primary bearing
surface 54 and the second shearing edge 52 of the second shearing
member 26 move toward and beyond the primary bearing surface 44 and
the first shearing edge 42 of the first shearing member 24.
Shearing the chain link defines a pair of severed ends in the chain
link. The shearing members 24, 26 cooperate to bend the severed
ends apart while the chain link is restrained against excessive
twisting by the secondary bearing surface 45 of the first shearing
member 24. Bending the severed ends defines an opening between the
severed ends of the chain link greater than the thickness of the
chain link.
[0048] Referring to FIG. 7, a support system 70 is provided to
support the first and second shearing members 24, 26 and to allow
the second shearing member 26 to rotate. The support system 70
includes a mounting block 72, a support plate 74, and a main pivot
bolt 76. The mounting block 72 mounts the first shearing member 24
to the housing 22 and secures the first shearing member 24 in a
substantially fixed position. The mounting block 72 is mounted to a
first side panel 80 of the housing 22 by welds 81 or other
fastening techniques, for example.
[0049] Referring to FIGS. 7 and 8, the mounting block 72 includes a
main bore 84 having a counterbore 86 to accommodate the threaded
portion of the main pivot bolt 76 and to engage the head of the
main pivot bolt 76 to retain it. The mounting block 72 includes
first and second mounting bores 88, 89 each having a counterbore
90, 91. First and second mounting bolts 92, 93 extend through the
mounting bores 88, 89. The counterbores 90, 91 engage the heads of
the mounting bolts 92, 93 to retain them. The threaded portions of
the mounting bolts 92, 93 threadingly engage first and second
tapped mounting holes 94, 95, respectively, of the first shearing
member 24 to secure the first shearing member 24.
[0050] Referring to FIG. 7, the support plate 74 is provided to
support the pivot bolt 76. The support plate 74 includes a blind,
tapped hole 97. The support plate 74 is mounted to a second side
panel 100 of the housing 22 across from the mounting block 72 by
welds 101 or other fastening techniques, for example. The hole 97
of the support plate 74 threadingly engages the threaded portion of
the pivot bolt 76.
[0051] The pivot bolt 76 is provided to serve the dual purpose of
securing one side of the first shearing member 24 and of providing
a fulcrum about which the second shearing member 26 can pivot. The
pivot bolt 76 acts as a rod that extends through the second
shearing member 26. The pivot bolt 76 is supported at each end by
the housing 22. The pivot bolt 76 defines one end point of a first
lever arm 102 of the second. shearing member 26, as shown in FIG.
5. Referring to FIG. 7, the pivot bolt 76 extends through the main
bore 84 of the mounting block 72, a main hole 103 of the first
shearing member 24, the fulcrum hole 63 of the second shearing
member 26, a thrust bearing 104, a flange nut 106, and a jam nut
108 and threadingly engages the support plate 74.
[0052] To minimize the spreading of the shearing members 24, 26
relative to each other, the thrust bearing 104, the flange nut 106
and the jam nut 108 are threaded onto the pivot bolt 76 and are
disposed to hold the shearing members 24, 26 between the thrust
bearing 104 and the mounting block 72. A setscrew 110 is disposed
in the flange nut 106 to selectively prevent the nut 106 from
moving. A setscrew can also be similarly disposed in the jam nut
108.
[0053] In the case where the apparatus 20 is used to cut wire rope
having a small diameter, {fraction (1/32)} inch, for example, the
clearance between the shearing members 24, 26 becomes an important
consideration. The support system 70 allows the clearance between
the shearing members 24, 26 to be controlled such that wire rope
having a diameter as small as {fraction (1/32)} inch, for example,
can be cut.
[0054] Referring to FIGS. 9 and 10, in another embodiment of the
support system, an L-shaped wall member 115 acts as a keeper and is
disposed such that the shearing members 24, 26 are disposed between
the mounting block 72 and the wall member 115. The wall member 115
is mounted to the second side panel 100 and a top panel 116 of the
housing 22 by welds 117 or other fastening techniques, for example.
The wall member 115 is provided to further retain the shearing
members 24, 26 in a cooperatively shearing relationship. The wall
member 115 includes a hole 119 to accommodate the main pivot bolt
76 and the thrust bearing 104. A washer 121, which is integral with
the flange nut 106, is disposed adjacent the thrust bearing 104 to
distribute the tightening force applied by the jam nut 108. A
setscrew 123 is threaded through the mounting block 72 and engages
the head of the pivot bolt 72 to prevent the unintentional rotation
of the pivot bolt 76. The support system shown in FIGS. 9 and 10 is
similar in other respects to the above-described support system 70
shown in FIGS. 7 and 8.
[0055] Referring to FIGS. 11 and 12, the electro-hydraulic actuator
system 28 is provided to cooperate with the second shearing member
26 and is selectively operable to move automatically the second
shearing member 26 between the open position and a cutting position
to generate the shearing and bending action between the primary
bearing surfaces 44, 54 of the first and second shearing members
24, 26, respectively. The actuator system 28 is selectively
operable to move automatically the second shearing member 26
relative to the first shearing member 24 to shear and bend the
chain link to define an opening in the chain link greater than the
thickness of the chain link. The actuator system 28 moves the
second shearing member 26 smoothly and consistently through a
substantially uniform stroke. The actuator system 28 requires no
priming.
[0056] The actuator system 28 includes a hydraulic cylinder 130, a
pump 132, a reservoir 134, and an electric motor 136. The hydraulic
cylinder 130 is cooperatively arranged with the second shearing
member 26 such that the cylinder 130 is operable to move the second
shearing member 26 to a cutting position to cut the chain link or
cable. The pump 132 is fluidly connected to the cylinder 130 for
driving the cylinder 130. The reservoir 134 has a quantity of
hydraulic fluid. The pump 132 is fluidly connected to the reservoir
134 for drawing the hydraulic fluid from the reservoir 134 and
pumping the hydraulic fluid under pressure to the hydraulic
cylinder 130. The motor 136 is operatively connected to the pump
132 for selectively driving the hydraulic cylinder 130. The motor
136 selectively powers the pump 132, which in turn drives the
hydraulic cylinder 130.
[0057] The cylinder 130 is a single-action type cylinder, such as a
seven-ton single acting type, for example. The hydraulic cylinder
130 has a base 140 and a driving rod 142 with a distal end 144. The
driving rod 142 is movable between a retracted position and an
extended position, having a 41/2 inch stroke, for example.
[0058] To allow the cylinder 130 to articulate with its stroke, the
base 140 of the cylinder 130 is pivotally mounted to a base clevis
146, which is in turn mounted to the housing 22. A rod clevis 148
is mounted to the distal end 144 of the driving rod 142. A pivot
end 150 of the movable shearing member 26 is pivotally mounted to
the rod clevis 148 by a pin 152. The pin 152 at the pivot end 150
and the pivot bolt 76 disposed in the fulcrum hole 103 define a
lever arm of the second shearing member 26.
[0059] The driving rod 142 of the hydraulic cylinder 130 operates
upon the lever arm for producing the shearing action between the
first and second shearing members 24, 26. The driving rod 142 moves
the movable shearing member 26 between the open position and a
cutting position. When the driving rod 142 is in the retracted
position, the movable shearing member 26 is in the open position.
When the driving rod 142 is in the extended position, the movable
shearing member 26 is in a cutting position.
[0060] A pair of return springs 160, 162 is cooperatively arranged
with the cylinder 130 to bias the driving rod 142 to the retracted
position, thereby positioning the movable shearing member 26 in the
open position. Each spring 160, 162 includes a pair of ends 164,
166 which are respectively mounted to the distal end 144 of the
driving rod 142 at the rod clevis 148 and to the base 140 of the
cylinder 130.
[0061] To spread the force loading associated with the cylinder 130
over a larger area to minimize deflection of the housing 22, a
cylinder base plate 169 is provided. The base plate 169 is mounted
to the housing 22 and is disposed between the base 140 of the
hydraulic cylinder 130 and the base 168 of the housing 22
[0062] The entire hydraulic system is closed. In operation, the
pump 132 draws an amount of hydraulic fluid from the reservoir 134
and pumps the fluid under pressure to the hydraulic cylinder 1130
on the power stroke thereof, thereby moving the driving rod 142 to
the extended position. The springs 160, 162 elongate and urge the
driving rod 142 to the retracted position. The spring force acts to
return the driving rod 142 to the retracted position, which in turn
forces the hydraulic fluid back into the reservoir 134. The
electro-hydraulic actuator system 28 moves the second shearing
member 26 smoothly and consistently through a substantially uniform
stroke at a substantially steady rate to allow the shearing members
to deliver a substantially constant force.
[0063] The motor 136 is electrically operated and is provided to
drive the pump 132. The electric motor 136 can be a 1/4 Hp motor
that operates on 115 VAC, 60 Hz, single phase power, for example.
The ready availability of such power facilitates the installation
and portability of the apparatus 20. The motor 136 includes an
internal auto-reset thermal overload protection device as an added
safety feature. In other embodiments, the motor can be a type that
operates on DC voltage.
[0064] Because the electro-hydraulic actuator system 28 moves the
second shearing member 26 relative to the first shearing member 24,
the shearing member 26 can move at a rate substantially above the
cutting members of manually-pumped prior art cutting devices. It
has been determined through experimentation that the cutting speed
at which the second shearing member 26 moves is an important design
consideration in maintaining the cutting edge and fracture
resistance of the shearing members 24, 26 when the apparatus 20 is
used to cut hardened chain. The actuator system 28 can be
configured to drive the second shearing member 26 at a selected
rate. The hydraulic cylinder 130 drives the shearing and bending
portion 32 of the second shearing member 26 preferably below a
speed of about 0.2 inches per second, more preferably at a speed of
about 0.10 inches per second, and even more preferably at a speed
of about 0.096 inches per second.
[0065] To provide a safety feature for the user and to provide full
control of the operation of the chain cutting apparatus 20, a
key-activated switch 170 is mounted to the housing 22 and
electrically arranged with the motor 136. The switch 170 allows for
selective operation of the motor 136. The key-activated switch 170
is movable by the key 34 between an operating position, in which
the motor 136 is running to operate the chain cutting apparatus 20,
and an off position, in which the motor 136 is shut off, thereby
stopping the chain cutting apparatus 20. The key-activated switch
170 is configured such that the switch 170 is biased to the off
position by a spring, for example. When the switch 170 is in the
operating position, releasing the key 34 allows the switch 170 to
return to the off position, thereby ceasing the cutting operation.
The key-activated switch 170 can help provide a further safety
feature by limiting the use of the chain cutting apparatus 20 to
only authorized, trained personnel.
[0066] Referring to FIG. 13, the key-activated switch 170 is part
of an ignition system 172 for electrically operating the motor. The
switch 170 is electrically connected to a plug 174 that can be
mated to an outlet in a standard convenience receptacle. A relay
176 and a condenser 178 are electrically connected to the plug 174
and the motor 136, thereby forming a circuit 180 between the switch
170 and the motor 136. Upon movement of the switch 170 to the
operating position, the circuit 180 is closed, thereby allowing
electricity to flow to the motor 136, which in turn starts to
operate. Releasing the key 34 allows the switch 170 to move to the
off position, which in turn opens the circuit 180, thereby
interrupting the flow of electricity to the motor 136. Accordingly,
the motor 136 stops running.
[0067] In other embodiments of the apparatus including an
electro-hydraulic actuator system having a DC motor, the relay 176
and the condenser 178 of the circuit 180 can be replaced with a
comparable AC/DC rectifier.
[0068] To operate the apparatus 20, the operator obtains the key 34
for the switch 170. A chain or cable for cutting is selected and
placed in the jaw 43 of the first shearing members 24. The chain
link can be positioned such that a portion of the chain link
extends through the shearing plane 41. An eye guard can be placed
over the shearing and bending portions 30, 32 of the first and
second shearing members 24, 26. The operator inserts the key 34
into the switch 170 and rotates the key 34 to the operating
position. The operator holds the key 34 in the operating position
to operate the apparatus 20 so that the second shearing member 26
undergoes its cut and open stroke. When the selected chain or cable
is cut and opened, the operator relaxes his hold on the key 34,
thereby allowing the switch 170 to move to the off position. When
the switch 170 is in the off position, the motor 136 stops running
which ceases the cut and open stroke of the second shearing member
26.
[0069] The internal bypass of the hydraulic cylinder 130 is opened
momentarily by opening the dump valve 36 to release any residual
hydraulic fluid pressure acting upon the driving rod 142, thereby
allowing the springs 160, 162 to position the driving rod 142 to
its fully retracted position, thereby moving the second shearing
member 26 to the open position, as shown in FIG. 13. It should be
noted that the driving rod stroke can be minimized by designing the
various components and positioning them in such a manner that the
fully retracted driving rod 142 defines the clockwise limit of
travel of the second shearing member 26.
[0070] When the driving rod 142 is in the retracted position, the
chain cutting apparatus 20 is ready to accept the next selected
chain link or cable for cutting. The operator can remove the cut
link or cable from the fully open jaws. The key 34 for the switch
170 can be returned to its controlled storage location.
[0071] Referring to FIG. 5, the illustrative first lever arm 102
has a length of 5.5 inches. An illustrative second lever arm 190
has a length of 1.625 inches. In embodiments of the chain cutting
apparatus having such lever arms 102, 190 and a hydraulic cylinder
that delivers a force between about 6,000 and about 14,000 lbs. at
a rate of about 0.330 inches per second, the jaw 55 of the second
shearing member 26 can deliver a shear force between about 20,310
and about 47,404 lbs. at a rate of about 0.096 inches per
second.
[0072] The first and second lever arm lengths 102, 190 of the
second shearing member 26 and the stroke of the driving rod are
selected to cause the primary bearing surface 54 of the second
shearing member 26 to move past the primary bearing surface 44 of
the first shearing member 24 to continue bending the link after it
has been severed, as shown in phantom lines in FIG. 12.
[0073] It will be appreciated that the shearing members are
preferably of substantial width for at least two reasons. First,
the high stresses to which the members are subjected require that
the members have sufficient strength to perform the above described
shearing and bending operations without permanent distortion which
would impair the subsequent operation of the apparatus. Second, the
bearing surfaces must be of sufficient area to assure that they
positively engage the severed ends of the link being cut and bent
apart.
[0074] On the other hand, shearing members of excessive width
increase both the cost and weight of the apparatus. It is
preferable, but not essential, that the members be of substantially
equal width so that they act similarly on both severed ends of the
link. It will be understood that in other embodiments the width of
the shearing members can vary. Satisfactory results have been
achieved using 3/4 inch wide steel shearing members to cut and open
3/8 inch products and 1 inch wide shearing members to cut and open
1/2 inch products.
[0075] The distribution of mass in both the first and the second
shearing members to provide adequate tensile strength at the points
of highest stress and shock is important to maintaining shearing
member integrity. The shearing members are configured to provide an
adequate amount of mass and cross section at high stress points to
give the necessary strength for fracture and cracking resistance.
The points of highest stress are located above the jaw on the
second, movable shearing member and below the jaw on the first,
stationary shearing member. It has been determined that the movable
shearing member made from solid tool steel has a critical mass with
a minimum cross section of 1.65 in..sup.2 for embodiments of
shearing members having a 3/4 inch width and of 2.24 in..sup.2 for
embodiments of shearing members having a 1 inch width. The
stationary shearing member made from solid tool steel has a
critical mass with a minimum cross section of 1.46 in..sup.2 for
embodiments of shearing members having a 3/4 inch width and of 2.10
in..sup.2 for embodiments of shearing members having a 1 inch
width.
[0076] In other embodiments, the shearing members can be made with
hardened tool steel inserts that are secured with dowel pins of
other fastening means. The hosting body for such an embodiment can
be a hardened high carbon steel.
[0077] The shearing members can be made from any suitable tool
steel, for example, such as O1, S-7, M-2, D-2, A-2, or A-6.
Preferably the material of the shearing members is tough enough to
withstand the shock of shearing and snapping hardened chain links
and is durable enough to continue to maintain a keen shearing edge
over many cuts. To maximize shock resistance, performance, and
cutting edge durability, the shearing members are preferably made
from S-7 tool steel, hardened to 59-60 Rc, and double tempered.
[0078] The mechanical advantage achieved through the use of the
actuator system and the lever arm enables large gauge chain to be
easily cut. The apparatus 20 is designed to create an opening
between the severed ends sufficient to allow the sheared and bent
link to be removed from the adjacent intact links. As explained
above, throughout the shearing and bending operations the secondary
bearing surface 45 of the first shearing member 24 bears upon the
link to prevent excessive twisting of the link which might
otherwise result. The twisting, if unrestrained, would impair the
capacity of the apparatus to generate a sufficient opening through
which the adjacent intact links could be removed. The apparatus can
cut chain links as large as 1/2 inch thick made from grade 100
metal, for example, and can cut wire rope as small as {fraction
(1/32)} inch, for example.
[0079] From the above detailed description, it is clear that under
normal operating conditions, the apparatus should require little
maintenance. Adjusting the support system 70 can readily compensate
for any wear between the shearing members 24, 26. Should the
shearing edges 42, 52 become worn or chipped, the shearing members
24, 26 may be readily removed for sharpening or replacement. Such
measures should be required infrequently, however, as the machine
is protected against harm resulting from excessive strain through
the safeguard of spacing primary and second bearing surfaces 44, 45
of the first shearing member 24 to accept only chains of manageable
size.
[0080] It is also apparent from the description and drawings that
bolts, cable, and other items having small cross sections can be
sheared with the apparatus. The overtravel of the primary bearing
surface 54 of the second shearing member 26 beyond the primary
bearing surface 44 of the first shearing member 24, utilized to
open a chain link after it has been severed, is superfluous for
these operations.
[0081] In addition, it will be understood that the chain cutting
apparatus can be operable with longer or shorter shearing members,
faster or slower pumps creating different hydraulic pressures, and
different cylinders having different cylinder bores and strokes.
Hydraulic valves and other devices, such as, flow controls or
pressure switches, for example, can be manually or electrically
actuated. Limit switches can be used to prevent overtravel.
Double-acting cylinders can be used instead of the illustrative
single-acting, spring-return cylinder. Various combinations of
these components are possible in other embodiments of the chain
cutting apparatus of the present invention.
[0082] All references, including publications, patent applications,
and patents, cited herein are hereby incorporated by reference to
the same extent as if each reference were individually and
specifically indicated to be incorporated by reference and were set
forth in its entirety herein.
[0083] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the invention (especially in
the context of the following claims) are to be construed to cover
both the singular and the plural, unless otherwise indicated herein
or clearly contradicted by context. Recitation of ranges of values
herein are merely intended to serve as a shorthand method of
referring individually to each separate value falling within the
range, unless otherwise indicated herein, and each separate value
is incorporated into the specification as if it were individually
recited herein. All methods described herein can be performed in
any suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein, is
intended merely to better illuminate the invention and does not
pose a limitation on the scope of the invention unless otherwise
claimed. No language in the specification should be construed as
indicating any non-claimed element as essential to the practice of
the invention.
[0084] Preferred embodiments of this invention are described
herein, including the best mode known to the inventors for carrying
out the invention. Of course, variations of those preferred
embodiments will become apparent to those of ordinary skill in the
art upon reading the foregoing description. The inventors expect
skilled artisans to employ such variations as appropriate, and the
inventors intend for the invention to be practiced otherwise than
as specifically described herein. Accordingly, this invention
includes all modifications and equivalents of the subject matter
recited in the claims appended hereto as permitted by applicable
law. Moreover, any combination of the above-described elements in
all possible variations thereof is encompassed by the invention
unless otherwise indicated herein or otherwise clearly contradicted
by context.
* * * * *