U.S. patent application number 09/725891 was filed with the patent office on 2002-05-30 for post puller.
Invention is credited to Salman, Mark T..
Application Number | 20020063245 09/725891 |
Document ID | / |
Family ID | 24916372 |
Filed Date | 2002-05-30 |
United States Patent
Application |
20020063245 |
Kind Code |
A1 |
Salman, Mark T. |
May 30, 2002 |
POST PULLER
Abstract
The post puller has an H-shaped base including a pair of
parallel legs and a crossbeam normal to the legs, the crossbeam
being offset from the midpoint of the legs and defining a shallow
channel and a deep channel. A pair of rectangular blocks attached
to the legs and crossbeam in the deep channel provide platforms on
which a pair of single action hydraulic cylinders are mounted, and
define a recess which straddles the post to be pulled. A cross
member is pivotally mounted to each cylinder rod. A chain is
suspended from the midpoint of the cross member. The chain may be
wrapped directly around the post, or a post gripping structure may
be attached to the free end of the chain. A pair of wheels may be
mounted to the base for portability.
Inventors: |
Salman, Mark T.;
(Greensboro, NC) |
Correspondence
Address: |
Richard C. Litman
LITMAN LAW OFFICES, LTD.
P.O. Box 15035
Arlington
VA
22215
US
|
Family ID: |
24916372 |
Appl. No.: |
09/725891 |
Filed: |
November 30, 2000 |
Current U.S.
Class: |
254/30 |
Current CPC
Class: |
E02D 13/02 20130101;
E04H 17/265 20130101 |
Class at
Publication: |
254/30 |
International
Class: |
E21B 019/00 |
Claims
I claim:
1. A post puller for pulling a ground-mounted post, comprising: a)
a base having a first leg and a second leg in parallel, spaced
apart relation for engaging the ground on opposite sides of the
post; b) a first hydraulic cylinder and a second hydraulic cylinder
attached to said base, each of the cylinders being an independently
operable unit having a cylinder base, an extensible rod having an
end slidable in the cylinder and a free end, and a pump handle
attached to the cylinder base; c) a cross member having a first end
pivotally attached to the free end of said first rod and a second
end pivotally attached to the free end of said second rod; d) a
chain depending from said cross member about halfway between said
first rod and said second rod; and e) wherein said chain is
attachable to the post and wherein said first and second hydraulic
cylinder rods may be extended simultaneously in order to pull the
post vertically from the ground.
2. The post puller according to claim 1, wherein said base further
comprises a crossbeam joining said first leg and said second leg in
parallel spaced relation.
3. The post puller according to claim 2, wherein said base is cast
in one piece.
4. The post puller according to claim 2, wherein said crossbeam is
normal to said first leg and said second leg and wherein said
crossbeam is offset from a midpoint of said first leg and said
second leg, said base defining a deep channel and a shallow
channel.
5. The post puller according to claim 4, wherein said base further
comprises: a) a first rectangular, box shaped platform joined to
said base in the deep channel at the junction of said first leg and
said crossbeam, said first hydraulic cylinder being mounted on the
first platform; b) a second rectangular, box shaped platform joined
to said base in the deep channel at the junction of said second leg
and said crossbeam, said second hydraulic cylinder being mounted on
the second platform; and c) wherein said first and second platforms
are spaced apart to define a recess, the post being positionable in
said recess.
6. The post puller according to claim 1, wherein said first and
second hydraulic cylinders are single action hydraulic
cylinders.
7. The post puller according to claim 1, wherein said cross member
comprises: a) a first elongated plate and a second elongated plate;
b) a plurality of fasteners joining said first plate to said second
plate; and c) a plurality of spacer sleeves disposed about said
fasteners in order to maintain said first and second plates in
parallel, spaced apart relation.
8. The post puller according to claim 7, wherein said plurality of
fasteners includes a center fastener disposed midway between the
free end of said first rod and the free end of said second rod,
said chain being attached to said center fastener.
9. The post puller according to claim 1, further comprising post
attachment means for attaching said chain to the post.
10. The post puller according to claim 9, wherein said post
attachment means comprises a hook.
11. The post puller according to claim 9, wherein said post
attachment means comprises a clamp.
12. The post puller according to claim 1, further comprising a
plurality of wheels attached to said base for transporting the post
puller.
13. The post puller according to claim 12, wherein said wheels are
mounted at a rear of said base and elevated so that said wheels are
raised above ground level when said legs are flush against the
ground and so that said wheels engage the ground when the post
puller is tilted to raise the legs above the ground.
14. A post puller for pulling a ground-mounted post, comprising: a)
a ground engaging base having two elongated legs and a crossbeam
normal to the legs defining an H-shaped base, the crossbeam being
offset from the midpoint of the two legs to define a deep channel
and a shallow channel; b) a first platform joined to one of said
legs and the crossbeam in the deep channel, and a second platform
joined to the other said leg and the crossbeam in the deep channel,
the first and second platforms defining a recess for straddling a
post; c) a first single action hydraulic cylinder mounted on said
first platform, the cylinder having a rod extendable from the
cylinder and a pump handle attached to the cylinder for actuating
the cylinder to extend and retract the rod; d) a second single
action hydraulic cylinder mounted on said second platform, the
cylinder having a rod extendable from the cylinder and a pump
handle attached to the cylinder for actuating the cylinder to
extend and retract the rod; e) an elongated cross member having a
first end pivotally attached to the rod of said first hydraulic
cylinder and a second end pivotally attached to said second rod,
the cross member having a center; f) a link chain attached to the
center of said cross member, the chain being aligned vertically
above the recess defined by said platforms, the chain being
attachable to the post; and g) wherein said first and second
hydraulic cylinders may be actuated sequentially to rock the post
from side to side and to adjust for sloping ground, and wherein
said cylinders may be actuated simultaneously to pull the post from
the ground without lateral movement of the post.
15. The post puller according to claim 14, wherein said base is
cast in one piece.
16. The post puller according to claim 14, wherein said base is
made from a lightweight aluminum alloy.
17. The post puller according to claim 14, wherein said base and
said first and second platforms are cast as a one piece unit.
18. The post puller according to claim 14, further comprising a
pair of wheels mounted on said base, said wheels being mounted at
an elevation above ground level when said base is engaging the
ground, and said wheels engaging the ground for transporting the
post puller when said post puller is tilted to raise said base off
the ground.
19. The post puller according to claim 18, further comprising a
pair of angle shaped brackets attached to said legs, each bracket
having an axle mounted thereon, said wheels being rotatably mounted
on said axles.
20. The post puller according to claim 14, further comprising post
attachment means for attaching said chain to a post.
Description
BACKGROUND OF THE INVENTION
[0001] 1. FIELD OF THE INVENTION
[0002] The present invention relates to a post puller for pulling a
post or a post anchor from the ground.
[0003] 2. DESCRIPTION OF THE RELATED ART
[0004] Several devices are supported by one or more posts driven
into the ground. Such devices include signs, mail boxes, fences,
and the like. The post may be a one-piece post with the load
carrying portion driven directly into the ground, or a two piece
post with a post anchor driven into the ground, and the upper or
load carrying portion of the post being driven or bolted to the
post anchor. For purposes of the present application, the term
"post" will be used to refer to either the one-piece or two piece
assembly, and to either a post or post anchor. From time to time it
may become necessary to remove or relocate the post. It then
becomes necessary to remove the post and/or the post anchor.
[0005] It is sometimes possible to remove the post manually. This
process is labor intensive, and may require striking the post from
several different directions with a sledge hammer to loosen the
ground about the post, and then leaning over and grabbing the post
and yanking the post out of the ground. Not only is the process
labor intensive, but the post may become damaged so that it cannot
be reused, and the laborer can sustain a back injury in the
process.
[0006] In order to obviate these problems, several machines or
mechanical devices have been developed. U.S. Design Pat. No.
372,177, issued Jul. 30, 1996 to S.C. Hansen, shows a mechanical
post puller with a single support post having a roller offset from
the top of the post and what appears to be a ratchet mechanism with
a C-shaped arm for gripping a post at the bottom of the support
post.
[0007] Several devices are adapted for use with a tractor, front
end loader, or other vehicle with a hydraulic system. U.S. Pat. No.
3,526,387, issued Sep. 1, 1970 to H. B. Fleming, describes a post
puller having a metal plate base with a flared opening for
straddling a post, a pair of uprights pivotally mounted on
opposites side of the flared opening, a single hydraulic cylinder
pivotally mounted to the base and connected to a vehicle hydraulic
system, a lever arm connected between the cylinder ram and the two
uprights, and a chain with a post gripping fixture depending from
the lever arm. U.S. Pat. No. 4,244,560, issued Jan. 13, 1981 to W.
H. Hawkins, discloses a tree puller attached to a front end loader
with a bifurcated wedging member for cutting into a tree trunk, a
pair of parallel ground engaging members, each having a hydraulic
cylinder mounted thereon with the cylinder rods being attached to
an elevatable frame, the wedging member also be attached to the
elevatable frame, so that the wedging member cuts into a tree trunk
and the cylinder rods are extended to lift the tree out of the
ground. U.S. Pat. No. 4,706,935, issued Nov. 17, 1987 to G. L.
Thompson, teaches a post puller attached to a tractor three-point
hitch, the puller including a stationary gripping plate and a
pivotally mounted arcuate gripper, both grippers having teeth for
clamping and gripping a post or tree therebetween.
[0008] Still other patents are primary concerned with the problem
of post slippage in the post puller, several such patents dealing
with T-shaped fence posts. U.S. Pat. No. 4,422,621, issued Dec. 27,
1983 to P. B. Ekern, shows a puller for pulling ranch fence posts
having lugs extending from the flange of a T-shaped post, the
puller having a pair of plated connected by a cross member, the
plates having a slot defined therein for receiving a pin which
lodges against a fence post lug. A chain is attached to the plates
and the post is pulled by a hydraulic cylinder or jack. U.S. Pat.
No. 5,011,117, issued Apr. 30, 1991 to Youngblood et al., describes
a post puller having a plate with a hole in it so that the plate
fits around the post. A chain pulls one side of the plate so that
the plate tilts and grips the side of the post to pull it out.
[0009] U.S. Pat. No. 5,368,277, issued Nov. 29, 1994 to F. Moss,
discloses a device for pulling a T-shaped fence post having a
bracket and a clevis which fits over the post and is pivotally
attached to the bracket. A ring is placed through the bracket and a
chain is looped through the ring. A lever is placed through the
chain and braced against the ground to pull the post.
[0010] A more remote device having some features in common with the
present invention is an apparatus for driving a pipe or other
elongated member horizontally through the ground, as described in
U.S. Pat. No. 4,746,096, issued May 24, 1988 to Donnell et al. The
apparatus uses a rectangular frame with a pair of parallel
hydraulic cylinders having rods attached to a tray by a cradle bar.
The tray has a plurality of pairs of spaced apart gussets which
support a moveable end plate which is placed at an end of a pipe to
be driven horizontally into the ground, the pipe being disposed
between the hydraulic cylinders. The cylinders are extended to move
the tray and pull the end plate against the pipe for the stroke
distance of the rods, the end plate is moved forward in the tray,
and the process is repeated to drive the pipe into the ground in
stages. Optionally, jaws may be attached to the tray for gripping
the pipe below collars placed on the pipe to pull the pipe out as
the cylinder rods retract.
[0011] Another device for a dissimilar purpose but having some
features in common with the present invention is a device for
lifting the foundation of dwellings, buildings and other
structures, described in U.S. Pat. No. 5,492,437, issued Feb. 20,
1996 to L. P. Ortiz. The device has a pier guide tube attached to a
support plate which fits under a foundation footing and has two
parallel hydraulic cylinders pivotally attached to the-guide tube.
The cylinder rams are pivotally attached to an articulating bar
having a pier compression means between the two rams. A pier is
placed into the guide tube and connected to the compression means.
One or more piers are driven into the ground until they reach
bedrock, after which further retraction of the rams raises the
structure. The pier is then permanently affixed to the foundation
and the hydraulic cylinders are detached.
[0012] There are several problems associated with the post pullers
known in the art. Several of the devices are expensive or heavy
devices which require attachment to a vehicle for operation. Many
manual pullers require that the operator complete the operation in
a bent position to extract the post, resulting in back strain and
related back injuries. Many puller devices apply a load from the
side of the post or utilize a pulling force with a large lateral
component relative to the axis of the post, making the post
difficult to extract. Consequently there is a need for a
lightweight, portable, relatively inexpensive post puller which
applies a pulling force primarily along the axis of the post.
[0013] None of the above inventions and patents, taken either
singularly or in combination, is seen to describe the instant
invention as claimed. Thus a post puller solving the aforementioned
problems is desired.
SUMMARY OF THE INVENTION
[0014] The post puller has an H-shaped base including a pair of
parallel legs and a crossbeam normal to the legs, the crossbeam
being offset from the midpoint of the legs and defining a shallow
channel and a deep channel. A pair of rectangular blocks attached
to the legs and crossbeam in the deep channel provide platforms on
which a pair of single action hydraulic cylinders are mounted, and
define a recess which straddles the post to be pulled. A cross
member is pivotally mounted to each cylinder rod. A chain is
suspended from the midpoint of the cross member. The chain may be
wrapped directly around the post, or a post gripping structure may
be attached to the free end of the chain. A pair of wheels may be
mounted to the base for portability.
[0015] The base assembly is preferably made from aluminum. The
entire post puller assembly is lightweight, permitting the post
puller to be easily transported on the optional wheels by hand,
without the need for a vehicle to transport the puller. The post
puller is a self-contained unit, and does not require attachment to
a vehicle hydraulic system. In use, each cylinder may be raised
individually to rock the post enough to loosen the ground
surrounding the post, and then the cylinders may be raised
simultaneously to pull the post straight up from the ground.
Therefore the unit is more efficient, directing the pulling force
along the axis of the post during final extraction of the post.
[0016] Accordingly, it is a principal object of the invention to
provide a portable post puller for pulling sign posts, mail box
posts, fence posts, and the like.
[0017] It is another object of the invention to provide a post
puller capable of exerting a pulling force directly on the axis of
the post.
[0018] It is a further object of the invention to provide a post
puller with a pair of hydraulic cylinders which may be operated
independently in order to pull a post vertically even on sloping
ground.
[0019] Still another object of the invention is to provide a post
puller with a cross member which may pivot on either side of the
post in order to loosen the post before pulling the post vertically
from the ground.
[0020] It is an object of the invention to provide improved
elements and arrangements thereof for the purposes described which
is inexpensive, dependable and fully effective in accomplishing its
intended purposes.
[0021] These and other objects of the present invention will become
readily apparent upon further review of the following specification
and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is an environmental, perspective view of a post
puller according to the present invention.
[0023] FIG. 2 is a front view of a post puller according to the
present invention.
[0024] FIG. 3 is a plan view of a post puller according to the
present invention.
[0025] FIG. 4 is a side view of a post puller according to the
present invention.
[0026] FIG. 5 is an environmental view of a post puller according
to the present invention removing a post from sloping ground, the
wheels being omitted.
[0027] Similar reference characters denote corresponding features
consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The present invention is a post puller, referenced generally
as 10 in the drawings, for pulling posts and post anchors from the
ground. As shown in FIG. 1, the post puller 10 is transported to
the post site, the base 20 is seated on the ground A with the legs
22 of the base 20 straddling the post B, the hoist chain 40 is
suspended directly above the post B, the free end of the chain 40
is attached to the post B, and the post B is pulled from the ground
by operation of a pair of hydraulic cylinders 60.
[0029] As shown in FIGS. 1-4, the post puller 10 has a base 20
which includes a pair of parallel legs 22 joined by a crossbeam 24
normal to the legs 22 defining a generally H-shaped base 20. As
seen most clearly in FIG. 3, the crossbeam 24 does not bisect the
legs, but is offset towards the rear of the base 20 to define a
deep channel 26 at the front of the base 20 and a shallow channel
28 at the rear of the base 20. A pair of flat, box shaped platforms
30 are attached to the base 20 at the junction of the legs 22 and
the crossbeam 24 on opposite sides of the deep channel 26 and
define a recess 32. The legs 22 and crossbeam 24 may be made from
square tubing which is joined by welding, but in a preferred
embodiment is made in one piece by casting, forging, molding, or by
other metal forming processes. In a preferred embodiment, the base
20 is made from a lightweight aluminum alloy, such as 356-T6.
[0030] The puller 10 has a pair of single action hydraulic
cylinders 60 mounted on the platforms 30 so that the two cylinders
60 are disposed on opposite sides of the recess 32. Each cylinder
60 has a base 62 which is fixedly attached to a platform 30 so that
the cylinder 60 does not pivot about its mounting point, an
extensible rod 64A and 64B, respectively, with a piston (not shown)
slidably disposed within the cylinder 60, and a pump handle 66 for
pumping hydraulic fluid through a one-way valve (not shown). The
rods 64A and 64B are retracted by releasing the one-way valve. The
internal construction of the cylinders 60 is conventional and well
known, and will not be further described herein. It will be noted
that each hydraulic cylinder 60 is a self-contained unit, requires
no connection to an external hydraulic system, and that each
hydraulic cylinder 60 is independently operated and actuated by its
pump handle 66.
[0031] The free end of each rod 64A and 64B is pivotally attached
to opposite ends of a cross member 70 by bolts 78A and 78B,
respectively, or other type of pivot pin. Cross member 70 is formed
by a pair of parallel plates 72 maintained in spaced apart relation
by at least one, and preferably a plurality of, bolts 74 which
extend through spacer sleeves 76, including a center bolt 74A which
bisects the distance between the end bolts 78A and 78B and the free
ends of rods 64A and 64B. Cross member 70 is positioned so that
center bolt 74A is disposed directly above the center of recess 32
when the base 20 is resting on a horizontal surface.
[0032] Hoist chain 40 is attached to the center bolt 74A so that
chain 40 is aligned with recess 32. Chain 40 may be attached to
center bolt 74A by any appropriate means, as by a hook, by
extending center bolt 74A through a link 42 in the chain 40 as
shown in FIG. 3, or by other conventional means. The free end of
the chain 40 is attached to a post B by any conventional means.
Such means may include wrapping the chain 40 around the post B with
overlapping loops, attaching a clamp, such as horseshoe clamp 44,
to the end of the chain 40 for gripping the sides of the post B, a
hook 46 (seen in FIG. 5) which may be inserted through a mounting
aperture in the post B, a gripper or clamp (not shown) which may be
attached to the post B by extending a bolt through the post and one
or more links in the chain 40, etc.
[0033] Optionally, the puller 10 may include a pair of wheels 80
mounted to the base 20 for transporting the puller 10. The wheels
80 may be attached to the base 20 by bolting a pair of mounting
brackets 82, which may have an angle iron shape formed by two
flanges defining a right angle, to the rear of legs 22, and
mounting axles 84 to the upstanding flange of brackets 82 so that
the axles 84 extend outboard from base 20. Wheels 80 are rotatably
mounted on axles 84 and may include pneumatic tires 86 mounted
about their rims. The diameter of wheels 80 are sized and
dimensioned so that the external perimeter of tires 86 are raised
above the ground by between about 1/2" to 1" when the base 20 is
flush against the ground A. In order to transport the puller 10,
the cross member 70 is grasped and the puller 10 is tilted rearward
until the tires 86 contact the ground A and the weight of the
puller 10 is balanced so that the puller may be wheeled about after
the fashion of a two-wheeled cart or dolly.
[0034] In use, the puller 10 is positioned with the base 20 flush
against the ground A with the post B disposed in recess 32. The
chain 40 is attached to the post B by any appropriate attachment or
post gripping means. Initially the operator pumps the handle 66 of
the cylinder 60 on one side of the puller 10 to raise the rod 64A,
the rod 64B on the other side remaining stationary while the cross
member 70 pivots about its end bolt 78B. Then the operator pumps
the handle 66 of the cylinder 60 on the opposite side to raise the
rod 64B while rod 64A remains stationary, the cross member 70
pivoting about end bolt 78B. The platforms 30 on opposite sides of
recess 32 act as a guide, preventing the puller 10 from moving or
walking during the pulling process. The operator may repeat the
process of alternately pumping first one cylinder and then the
other to rock the post B to loosen the surrounding soil, the cross
member 70 acting as a second class lever alternately pivoting about
one fulcrum 78B and then the other 78A. Finally the operator pumps
both handles 66 simultaneously to exert maximum pulling force
directly along the axis of the post B, without a net lateral
component which might shift the post B to one side or the other,
until the post B is extracted from the ground A.
[0035] FIG. 5 illustrates use of the post puller 10 to remove a
post B from sloping ground A. Since the cylinders 60 may be
operated independently, the rod 64A on the lower side may be
extended a greater distance than the rod 64B on the higher side
until the cross member 70 is level, and then both rods 64A and 64B
may be extended simultaneously to raise the post B vertically on
sloping ground.
[0036] The puller 10 has a wide base 20 with elongated legs 22 in
order to distribute the pulling force over a wide area of the
ground A while exerting a large pulling force on the post B, as
compared to pullers which exert a pulling force only from one side
of the post. By applying parallel and equal pulling forces from
opposite sides of the post B, a greater pulling force may be
applied for easier extraction of the post B. Advantageously, the
mechanical advantage applied by the employment of parallel
hydraulic cylinders 60 to extract posts from the ground reduces the
likelihood of back strain and related ailments incurred during post
pulling operations.
[0037] It is to be understood that the present invention is not
limited to the embodiments described above, but encompasses any and
all embodiments within the scope of the following claims.
* * * * *