U.S. patent number RE32,847 [Application Number 06/939,065] was granted by the patent office on 1989-01-31 for wedge-type rope socket connection and method.
This patent grant is currently assigned to ESCO Corporation. Invention is credited to Terry L. Briscoe, Robert L. Van Hoomissen.
United States Patent |
RE32,847 |
Briscoe , et al. |
January 31, 1989 |
Wedge-type rope socket connection and method
Abstract
A socket-wedge connection for wedge-type rope socket wherein a
multi-part wedge is employed having one part collapsible, finding
advantageous use, for example, in the lines employed with
excavating equipment.
Inventors: |
Briscoe; Terry L. (Portland,
OR), Van Hoomissen; Robert L. (Toledo, OH) |
Assignee: |
ESCO Corporation (Portland,
OR)
|
Family
ID: |
27084580 |
Appl.
No.: |
06/939,065 |
Filed: |
December 8, 1986 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
604063 |
Apr 26, 1984 |
04561154 |
Dec 31, 1985 |
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Current U.S.
Class: |
24/136R; 24/115M;
24/136K; 24/136L; 403/211 |
Current CPC
Class: |
F16G
11/046 (20130101); Y10T 24/3973 (20150115); Y10T
24/3996 (20150115); Y10T 24/3971 (20150115); Y10T
403/4345 (20150115); Y10T 24/3969 (20150115) |
Current International
Class: |
F16G
11/04 (20060101); F16G 11/00 (20060101); F16G
011/04 () |
Field of
Search: |
;24/136R,115R,115M,136K,136L,134WL ;403/211,16,213,409
;285/421 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sakran; Victor N.
Attorney, Agent or Firm: Tilton, Fallon, Lungmus &
Chestnut
Claims
We claim;
1. A socket-wedge connection for the wedge-type rope socket for an
excavating bucket or the like comprising a relatively elongated
socket having a larger end and a smaller end, a tapered passage
extending from one end to the other, a rope in said passage looped
upon itself to provide two lengths of rope in said passage with a
loop adjacent said larger end, and a relatively elongated wedge
between said two lengths, said wedge having a pair of
longitudinally-extending wedge-forming means with collapsible
insert means therebetween for relieving pressure on said two
lenghts, said insert means including a plurality of longitudinally
tapered block means arranged to slide relative to each other unless
constrained against relative longitudinal movement.
2. The connection of claim 1 in which the angle of block taper has
a tangent greater than the coefficient of friction between adjacent
blocks.
3. The connection of claim 1 in which said insert means includes a
heat destructible housing means for said block means to provide
longitudinal constraint.
4. Socket-wedge for a wedge-type rope socket connection of an
excavating bucket comprising two wedge-forming halves pivotally
interconnected adjacent the small wedge end and equipped with
confronting surfaces adjacent the larger wedge end, and a
collapsible insert between said surfaces, said insert including a
plurality of stacked tapered blocks adapted to slide relative to
each other in the absence of longitudinal constraint.
5. The wedge of claim 4 in which said blocks are constructed of
polished steel and the angle of taper is at least about
12.degree..
6. A method of manipulating a wedge-type rope socket connection for
an excavating bucket or the like comprising providing a relatively
elongated socket having a tapered passage extending from one end to
the other, installing a multiple-part wedge and rope in said
passage wherein said wedge includes outer tapered members and a
collapsible insert and, when disassembly of said connection is
required collapsing said element, said insert including a plurality
of stacked tapered blocks slidable with respect to each other upon
removal of a block sustaining force, and said collapsing step
includes removal of said sustaining force. .Iadd.
7. A collapsible support for resisting a clamping force comprising
three stacked, longitudinally tapered members arranged to slide
relative to each other, wedge-forming means including an element
adjacent each of the end members of said stack for applying a
compressive load to the stack end members, the middle of the three
stacked members having an angle of taper relative to each of the
adjacent end members, said angle of taper having a tangent greater
than the coefficient of friction between adjacent members, and
housing means operably associated with said three members
releasably constraining the same against sliding movement
longitudinally relative to each other, whereby when said
constraining housing means is removed, the middle of said members
automatically is ejected relative to said adjacent end members to
relieve said compressive load.
Description
BACKGROUND AND SUMMARY OF INVENTION
This invention relates to a wedge-type rope socket connection and
method and, more particularly, to a connection which is readily
disassembled in the field when used as part of the dragline, hoist
line or dump line of a dragline bucket or any of the attaching
lines for a cable shovel, cable hoe, etc.
The general environment where the invention finds application is
seen in co-owned U.S. Pat. No. 3,681,808. For example, wedge-type
rope sockets are employed to secure the wire ropes forward and
above the bucket for operating the same. Essentially, the socket is
a relatively elongated member having a smaller end and a larger end
and a tapered passage extending therethrough. The wire rope is
looped on itself and held in place by a wedge.
At present, these wedges, because of their difficulty of removal,
are being blown out by various forms of cannons, are being pressed
out in shops, etc. Almost every form of present removal requires
either a large sledge, a pendulum ram, or cannon, all of which
could be very dangerous because of the resultant force required to
remove the wedge. In addition to the safety factor, the currently
used construction results in expensive down-time in the case of
rope change-out. Some of the large machines incur a down-time cost
of approximately $5,000 per hour and the change-out of a dump rope
can take as long as three to four hours. This also applies to such
prior art expedients as seen in U.S. Pat. No. 3,905,711.
The invention avoids these disadvantages through the provision of a
multi-part wedge which includes a pair of longitudinally extending
wedge forming means along with a collapsible insert means there
between. More particularly, the insert means can take the form of
wedge shaped parts slidable relative to each other when the
constraining force exerted by the rope loop is removed or by a heat
destructible element, or both.
Other objects and advantages of the invention may be seen in the
details of the ensuing specification.
The invention is described in conjunction with the accompanying
drawing, in which
FIG. 1 is a fragmentary perspective view of a portion of a dragline
featuring the socket with the inventive wedge;
FIG. 2 is an enlarged longitudinal section such as would be seen
along the sight line 2--2 of FIG. 1;
FIGS. 3-6 are transverse sectional views taken along the sight
lines 3--3, 4--4, 5--5, and 6--6, respectively, of FIG. 2;
FIG. 7 is an exploded perspective view of the socket and wedge of
the invention;
FIG. 8 is a perspective disassembled view showing the wedge about
to be inserted into the socket with the wire rope shown in dashed
line;
FIG. 9 is a sectional view similar to FIG. 2 but with the wire rope
severed so as to illustrate the method of disassembling the
connection;
FIG. 10 is a side elevational view of a modified form of wedge
insert;
FIG. 11 is a longitudinal sectional view of a modified form of the
inention; and
FIG. 12 is a perspective view of the insert employed in FIG.
11.
DETAILED DESCRIPTION
In the illustration given and with reference first to FIG. 1, the
numeral 20 designates generally the wedge socket connection which
is seen to include a socket 21 adapted to be connected to a
shackle, a wire rope 22 looped on itself and a wedge 23 holding the
looped rope in place. As mentioned previously, the inventive
connection finds utility in applications such as are seen in
co-owned U.S. Pat. No. 3,681,808 and reference may be made to that
patent for additional details of construction, operation and
environment not set forth here.
The socket 21 as can be most readily appreciated from FIG. 8 is a
relatively elongated member having a passage or bore 24 extending
there through from the smaller end 25 to the larger end 26. A
variety of socket constructions can be employed in the practice of
the invention and the socket illustrated is but one advantageous
form--having a shackle connection at the rear end.
The wedge 23 can be seen in exploded form in FIG. 7 and is seen to
include a pair of longitudinally extending wedge forming means 27
and 28.
The identical wedge forming means, i.e., the members 27 and 28 are
pinned together by means of a pin 29--still referring to FIG. 7. At
the larger wedge end, the members 27, 28 are separated by the
insert means generally designated 30.
OPERATION GENERALLY
After the wedge 23 is assembled in the configuration illustrated in
FIG. 8, the wire rope 22 is looped about the larger end of the
wedge 23 as illustrated in dotted line to provide two lengths 31
and 32 for mounting in the socket 21. As tension T is exerted on
the rope 22 as illustrated in FIG. 1, the looped rope and wedge are
cinched into place within the socket 21 as illustrated in FIGS. 1
and 2.
When it is necessary to disassemble the wedge and socket, the rope
loop is cut--as by burning--in the area of the notch or recess 33
provided adjacent the larger end of the upper member 27. It will be
noted that a similar recess is provided in the member 28 so that it
makes no difference which of the identical members is positioned
upwardly. Upon severance of the rope 22, the larger end of the
insert means 30 is exposed.
In the illustration given, this exposes the larger end of the
housing 34--see FIG. 7. The housing 34 is constructed of zinc and
hence is easily meltable by means of a torch. When the rear end
wall 34a (still referring to FIG. 7) is melted, the element stack
35 collapses. This in turn eliminates pressure on the members 27,
28 and thus on the rope lengths 31, 32. There upon, the wedge 23
can be readily removed.
STACKED ELEMENT
The element 35 includes three friction blocks 36, 37 and 38. These
blocks are machined at an angle roughly 12.degree. which
corresponds to the coefficient of friction of polished steel on
polished steel, and therefore these three blocks stacked on top of
one another would not stand up but instead slide apart. The
advantageous feature of this construction is that with a very small
amount of force on both sides of these three pieces, one can
maintain their stability from sliding apart and therefore increase
their load carrying capability substantially. However, once the
retraining force on the back of these three blocks is removed,
i.e., the rear wall 34a of the zinc housing 34, then these blocks
collapse readily and allow the wedge forming halves to collapse,
thus facilitating removal of the entire wedge 23 from the
socket.
More particularly, in the illustration given, the angle at which
the blocks is machined is that angle whose tangent is slightly
greater than the coefficient to friction between the adjoining
blocks.
It will also be appreciated that in certain instances the zinc
housing 34 may be eliminated inasmuch as the uncut rope 22 itself
provides the above described restraining force.
By the same token, it is possible to utilize only a collapsible
element such as the block of zinc illustrated in FIG. 10. Zinc is
chosen because of its relatively low melting point--of the order of
less than 800.degree. F. Collapse via melting of the insert means
130 of FIG. 10 is provided by means of a heating coil C embedded
therein and equipped with suitable leads for connection to a source
of DC current--virtually always available on the site of dragline
bucket operations.
Wedge Forming Means
The details of the wedge forming means 27, 28 can be best
appreciated from a consideration of FIG. 7 along with the sectional
views of FIGS. 3-6 which are indicated on FIG. 2.
Referring first to FIG. 7, the numeral 39 designates the front
bearing area of the wedge which comes into contact with its
symmetrical partner when the wedge is assembled.
Just rearward of the front bearing area is the pin boss 40 which is
equipped with a hole 42 for the receipt of the pin 29. The pin 29
is employed to pin the wedge halves 27, 28 together to hold them
together prior to installation of the composite wedge 23. The pin
29--see FIG. 7--is equipped with an annular,
centrally-longitudinally located recess 41 to accommodate a split
locking ring 43--see the left hand portion of FIG. 2.
Rearward of the boss 40--referring again to FIG. 7--each wedge
forming means 27, 28 is equipped with a recess 44 on one
longitudinally extending side and an ear 45 on the other
longitudinally extending side. These mate together in the fashion
illustrated in FIG. 4.
Also to be noted is that each wedge forming means or half 27, 28 is
equipped with a longitudinally extending groove as at 46--best seen
in the upper portion of FIG. 7 relative to the wedge forming half
27. This groove or recess continues from the front all the way
around the rear or larger end to provide a trough for the seating
of the wire rope loop.
The corresponding ears and recesses 45, 44 provide for lateral
stability of the wedge 23 in the front to back direction so that
the wedge does not slip sideways and put torsional loading on the
pin 29.
The recesses and ears 44, 45 are similar to recesses and ears 47,
48 provided just rearwardly of the recesses and ears 44, 45. The
interrelationship of the recesses and ears 47, 48 can be
appreciated from a consideration of FIG. 5.
The recesses and ears 44, 45 and 47, 48, together with the pin
bosses 40 and pin receiving openings 42 provide three pairs of
corresponding surfaces along the wedge 23--which make the wedge
very stable longitudinally.
As can be seen, upon installation, the ears 45 fit into the
recesses 44 when the wedge is both collapsed and in the full open
position. The same applies to the ears 48 and recesses 47.
More particularly, each ear 48 is equipped with a tab 49 (compare
FIGS. 5 and 7). Each recess 47 is equipped with an intermediate
shoulder 50 for bearing cooperation with the tab 49. In operation,
the tab 49 comes into contact with the projection or shoulder 50
and allows the wedge halves to open only to a maximum of about
51/2" at the back--the amount of opening, of course, depending upon
the size of the wedge and socket--which in turn are governed by the
capacity of the dragline bucket. In any event, this limited
movement eliminates the load being taken on the pin 29 and the
mating surfaces 39--but instead has a contact when the wedge is in
the full open position between tab 49 and shoulder 50 and on
surface 39 which is the bearing surface. This takes all the load,
shear load and torsional load, off the pin and allows for a more
durable and tighter fit.
Area 51 is the back surface area and the area along which the
removable insert 30 slides along to effect engagement of the wedge
23 with the rope 22 and hence the socket 21. Each surface 51 is
arranged at a slight angle with respect to the longitudinal
midplane of the wedge 23, i.e., diverging rearwardly of the order
of about 3.degree. to allow easy installation of the insert 30 but
yet virtually a parallel plane for frictional requirements.
In the illustration given, the rear bearing surfaces 51 each have a
1/2" deep groove as at 52 for the support of the insert 30 so that
the insert does not slide sideways or become dislodged after
engagement into the wedge. For this purpose we provided stabilizers
in the nature of fins 53 and which are also designated in FIG. 10
by the numeral 153.
As indicatied, the inventive wedge has a collapsible insert which
allows the wedge to collapse at the back and eliminates pressure on
the rope to the side of the socket. After relieving this pressure,
the wedge can be removed much more easily than when the frictional
force normally present would have to be overcome.
Also, at present, the state of the art wedges because of difficulty
of removal, require extensive force for removal which is dangerous
whereas the new wedge requires only heat as by a cutting torch.
This results in decreasing down time of the machine.
The wedge when assembled is one tight unit and handling is the same
as with the present wedge. However, when the unit is removed, the
wedge still remains as a unit which can be reused with another
insert.
The inventive socket-wedge assembly provides better rope life and
in testing, we have found that rope breaking strength was improved
as much as 10-15% over previous tests run on the same type of
socket.
The invention also decreases rope slippage. Another major complaint
about wedge-type sockets is the rope slippage when being used in a
cyclical application. With the inventive wedge, which can be easily
removed, we can now allow for smaller included angles in the socket
and higher wedging action. This higher, tighter wedging action can
decrease the possibility of rope slipping before removal is
desired.
Still further, the invention reduces damage to sockets. At present,
with the cannon or the pendulum ram, there is a certain amount of
damage which occurs in the front of the socket due to the high
impacts which are required to remove the wedge. With the inventive
insert, the wedge is simply and easily removed with very little
damage occurring to the socket.
DETAILS OF OPERATION
As a specific example of the wedge 23, the length of each wedge
forming means or half 27, 28, is 30", the width about 41/2" and the
height of each half about 7" at the maximum divergence of the
grooved side. The two halves 27, 28 (see particularly FIG. 7) are
moved longitudinally relative to each other to have the various
recesses and ears 44, 45 and 47, 48 interengaged. At this stage,
the snap ring 43 (see FIG. 3) is interfitted between confronting
recesses so that when the pin 29 is inserted into the aligned holes
42 in the bosses 40, it can be maintained in place.
Thereupon the insert 30 is assembled utilizing the housing 34 and
the three tapered block 36-38. These are then inserted into the
recess in the housing 34 in the fashion indicated in FIG. 7.
The wire rope 22 is inserted through the opening 24 and folded on
itself as indicated in FIG. 8, lying in the grooves 46 of each of
the wedge forming halves 27, 28. With the wedge and rope in the
position indicated in FIG. 8, the rope is tensioned so as to pull
the assembly into the tapered socket opening 24.
Both sets of recesses and ears 44, 45 and 48, 49 assist in
maintaining longitudinal alignment and the removal of shear and
torsional forces on the pin 29.
The tabs 49 and shoulders 50 limit the spacing apart of the two
halves 27, 28 due to the interposition of the wedge means 30.
When wedge removal is indicated, the rope is severed by burning
through in the area of the notch 33 to arrive at the FIG. 9
configuration. Thereafter, the torch is applied to the now-exposed
rear of the zinc housing 34 to free the stacked elements 35.
Because these elements are related by an angle greater than the
coefficient of friction, the removal of the longitudinal constraint
permits these elements to slide relative to each other and eject
the central element 37. This results in a collapse of the wire
clamping force so that easy removal of the wedge is
facilitated--and without the extraordinary expedients of the prior
art.
The collapsible element may be the central block of a stack as seen
in FIG. 10 or may be a unitary element which is substituted for the
entire stack as seen in FIGS. 11 and 12 where the element is
designated 230, having an integral fin or rib 253 and embedded
heating coil C.
While in the foregoing specification, a detailed description of an
embodiment of the invention has been set down for the purpose of
illustration, many variations in the details hereingiven may be
made by those skilled in the art without departing from the spirit
and scope of the invention.
* * * * *