U.S. patent number RE32,532 [Application Number 06/941,686] was granted by the patent office on 1987-10-27 for pipelaying appliance.
Invention is credited to John T. Sonerud.
United States Patent |
RE32,532 |
Sonerud |
October 27, 1987 |
Pipelaying appliance
Abstract
A pipelaying appliance (1) is removably connected to the bucket
(2) of an excavator with the aid of a gripping means (3) mounted on
the bucket. The appliance includes two gripping arms (7, 8) of
which one thrusts into the pipe (9) and the other is situated on
the outside of the pipe. The gripping arms are movable to and from
each other and are connected to the appliance so that the clamping
force of the gripping arms on the pipe wall will be proportional to
the weight of the pipe carried by the appliance.
Inventors: |
Sonerud; John T. (S-824 00
Hudiksvall, SE) |
Family
ID: |
20345808 |
Appl.
No.: |
06/941,686 |
Filed: |
December 15, 1986 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
459118 |
Jan 19, 1983 |
04515522 |
May 7, 1985 |
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Foreign Application Priority Data
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Jan 22, 1982 [SE] |
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8200365-8 |
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Current U.S.
Class: |
414/745.4;
37/406; 414/746.5; 294/103.2; 294/67.22; 414/724; 414/740;
414/910 |
Current CPC
Class: |
F16L
1/065 (20130101) |
Current International
Class: |
F16L
1/06 (20060101); E02F 005/00 () |
Field of
Search: |
;414/724,740,745,747,908,910 ;37/117.5,DIG.3,DIG.12
;294/67.22,103.2,104 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2228903 |
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Dec 1974 |
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FR |
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629157 |
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Sep 1978 |
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SU |
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Primary Examiner: Paperner; Leslie J.
Attorney, Agent or Firm: Paul & Paul
Claims
I claim:
1. A pipelaying appliance, connected to a raisable and lowerable
apparatus such as an excavator or a crane, and including a gripping
means for removable engagement with a pipe, said means comprising a
first member projecting into the pipe and an opposing second member
on the outside of said pipe, said first and second members being
movable to and from each other and connected to said appliance so
that the clamping force provided by said first and second members
on the wall of said pipe will be proportional to the weight of said
pipe carried by said gripping means, characterized by a spring
means exerting a force on both said first and second members for
the mutual displacement thereof when they are not in engagement
with said pipe, the weight of which substantially exceeds this
force, wherein the first member is L-shaped with a substantially
horizontal arm engaging said pipe and a substantially vertical arm
parallel to a third member on said appliance, said third member
being connected to said raisable and lowerable apparatus and
movably connected to said vertical arm via a link and a portion of
said second member parallel to said link.
2. Appliance as claimed in claim 1, characterized in that the
angular attitude of said first member relative to the horizontal
plane is substantially unaltered during its insertion into, and
support of said pipe.
3. Appliance as claimed in claim 1, characterized in that said
substantially horizontal and vertical arms engaging with said pipe
carried by said gripping means are clad with elastic material.
4. Appliance as claimed in claim 1, characterized in that said
third member comprises a rod or bar which can removably be gripped
by a second gripping means mounted on an excavator independent of
how said rod or bar is turned around its longitudinal axis.
5. Appliance as claimed in claim 1, characterized in that said
spring means acts between said first member and said third
member.
6. A pipelaying appliance, connected to an excavator bucket and
including first and second gripping means said first gripping means
for removable engagement with a pipe, said first gripping means
comprising a first member projecting into said pipe and an opposing
second member on the outside of said pipe, the members being
movable to and from each other and connected to said appliance so
that the clamping force provided by said first and second members
on the wall of said pipe will be proportional to the weight of said
pipe carried by said first gripping means, at least one of said
first and second members being connected to a bar to be removably
gripped by said second gripping means mounted on said excavator
bucket and remotely controlled by the excavator operator whereby
said bar and said appliance will assume one of an infinitely
variable number of positions in relation to said excavator bucket.
Description
DESCRIPTION
1. Technical Field
The present invention relates to a pipelaying appliance connected
to a raisable and lowerable apparatus such as an excavator or a
crane, and including a gripping means for removable engagement with
a pipe.
2. Background Art
In pipelaying different types of gripping scissors are used for
holding the pipe, these scissors hanging freely in slings or on the
safety hook of an excavator. These gripping scissors must be
manually coupled up to, and uncoupled from the excavator, and
manual work is also required to connect the scissors to, and remove
them from the pipes. The manual connection is done by a person
standing on the ground, and the aligning of a pipe in the pipe
trench and the removal of the gripping scissors is carried out by
this person when he has got down into the trench. After having
joined the pipe to a previously laid pipe with the aid of a special
lever means, the person gets up out of the trench again and
releases the scissors from the excavator so that the latter can
continue with excavation.
This procedure is both time-consuming, labourious and uneconomical.
Furthermore there are large accident risks, since the heavy pipes
can sway unchecked during the movement to, and lowering into the
pipe trench.
DISCLOSURE OF INVENTION
One object of the present invention is to do away with the
disadvantages burdening previously known pipelaying appliances, and
to provide an appliance gripping a pipe with a force corresponding
to the weight of the pipe, which eliminates damage to light pipes
and also that heavy pipes are gripped with insufficient force, the
machine operator himself being able to couple the appliance to, and
uncouple it from the machine, perform the necessary operations
himself for gripping a pipe, take it down into an excavated trench,
e.g. one parallel to or right angles to the excavating direction,
align the pipe in the trench and thereafter release the pipe.
This object is achieved by the invention being given the
characterizing features disclosed in the claims.
DESCRIPTION OF FIGURES
FIG. 1 is a schematic side view of a pipelaying appliance in
accordance with the invention, connected to an excavation bucket
provided with a gripping means and in position for gripping a
cement pipe, and
FIG. 2 is a side view similar to the one in FIG. 1 but with the
appliance gripping and lifting the cement pipe.
PREFERRED EMBODIMENT
The appliance I illustrated in the Figures is intended to be
gripped by a gripping means mounted on a raisable and lowerable
apparatus, e.g. a crane or an excavator of the kind illustrated in
the Swedish Patent Specification No. 7714027-5. In the Figures, the
raisable and lowerable apparatus is illustrated in the form of a
portion of the mentioned excavator bucket 2 with a gripping means 3
comprising two fingers movable to and away from each other which
are pivotably mounted on the back of the bucket.
The appliance 1 comprises a bar or upright 4 suitably provided with
a circular cross section, which can be gripped by the gripping
means 3, independent of how the upright is rotated round its
longitudinal axis, the bar being provided with an upper plate 5
intended to engage with a portion thereof against the upper surface
of the bucket 2 to prevent the appliance from sliding downwards
between the fingers 3 when the appliance carries a heavy pipe. At
the lower portion of the upright 4, projecting somewhat farther
from the bucket 2 than the upper portion thereof, so that the
machine operator will be able to see the remaining part of the
appliance better during pipelaying, there are pivotably mounted the
first ends of a link 6 and a gripping arm 7. The other end of the
link 6 and an intermediate portion of the gripping arm 7 are
pivotably mounted in the vertical arm 8a of an L-shaped arm 8. The
four journalling points constitute the corners in a parallelogram
formed by the details just described, this parallelogram being
variable between the shapes illustrated in FIGS. 1 and 2. The
horizontal arm 8b of the gripping arm 8 and the somewhat downwardly
angled right-hand portion 7a of the gripping arm 7 form the jaws in
the means gripping a cement pipe 9.
A spring means, suitably a so-called gas spring 10, is pivotably
mounted on, and extends between the lower portion of the upright 4
and the upper part of the arm 8a. The pressing force in the spring
10 is somewhat greater than the sum of the weight of the link 6,
arm 7 and arm 8, so as to keep the jaws 7a and 8a in the open
position illustrated in FIG. 1.
When a length of trench in which it is intended to lay cement
piping is excavated by the bucket 2, the bucket is manoeuvered by
the machine operator so that it is moved to the appliance 1, lying
or upright on the ground at the side of the trench, the gripping
means 3 then being opened and caused to surround and grip the
upright 4 of the appliance, the bucket then being lifted and turned
so that it and the appliance assume the attitude illustrated in
FIG. 1. The appliance 1 is then aligned so that the arm 8b of the
gripping arm 8 is inserted in the end of the cement pipe 9 having
an enlarged flange 9a, and the gripping arm portion 7a is moved to
a position on the outside of the pipe opposite the arm 8b. The arm
8b is inserted into the pipe until a rubber-covered portion of the
arm 8a comes against the flange 9a.
The bucket 2 is now raised, whereon the arm 8b is lifted into
contact with the inner wall of the pipe 9 and is pressed against
it, the spring means 10 thus being compressed by a force
corresponding to the compressing force. When the compressing force
has been surmounted, the gripping arms 7 and 8 and remaining
portions of the appliance assume the positions illustrated in FIG.
2, with the rubber-covered arms 7a and 8b exercising a light
clamping action on the pipe wall.
In continued raising of the bucket 2, the pipe 9 is lifted by the
arm 8b, it and the arm 7a still keeping the positions illustrated
in FIG. 2, and are pressed against the pipe wall by a force
corresponding to the weight of the pipe. This is important, since a
large clamping force is required to retain heavy pipes, and since
smaller and more frangible pipes must not be subjected to clamping
forces so large that they break. To improve retention of the pipe,
the arm 7a should be somewhat inclined, so that it engages against
the pipe in the area where the flange 9a merges into the
cylindrical pipe wall. The rubber cladding on the arms 7a and 7b
increases the friction between these and the pipe, thereby
improving retention, as well as preventing the pipe from being
damaged.
The bucket 2 is then swung in the horizontal plane to a position
above the trench, and the bucket lowered into the trench such that
the gripped pipe will be in line with pipes previously laid in the
trench. The bucket is then moved forwards (to the right in FIG. 2)
so that the righthand end of the pipe is inserted in a pipe the
same as the pipe 9. After the pipe 9 has been inserted in the
previously laid pipe, the bucket 2 is lowered, for separating the
arms 7a and 8b from each other and releasing their grip on the pipe
wall. If the pipe 9 is to be thrust further into the previously
laid pipe, the bucket can be manoeuvered so that the rubber
cladding on the arm 8a presses the flange 9a to the right.
The appliance 1 is now removed from the pipe 9 and can be used to
lay a further pipe in the trench, or it can be uncoupled from the
bucket by opening the gripping means 3 and laid on the ground
adjacent the trench for use when one or more new pipes are to be
laid in a further portion of the trench excavated by the
bucket.
Although only one embodiment of the invention has been shown and
described, it should be understood that the invention is not
limited to this embodiment but only by the disclosures in the
claims.
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