LINGUET DE SECURITE POUR ENFONCE-PIEUX

POST DRIVER SAFETY LATCH

Abrégé anglais

A safety latch for supporting a post in a post driver while the post is being
driven
into the ground. A post-engaging roller is mounted on a lever arm that is
pivotally
attached to the post driver and moveable between a released position for
positioning of a
post in the post driver and a working position where the roller is in
supporting
engagement with the post. A spring biases the roller to maintain supporting
engagement
with the post while it is driven. In a preferred embodiment, the spring is
part of an
over-center device for biasing the safety latch to both the released and
working positions
depending on which side of center the lever arm is positioned.

Revendications

We claim:
1. A post driver safety latch, comprising:
(a) mounting apparatus secured to the post driver,
(b) a lever arm mounted on the mounting apparatus for pivotal movement;
(c) engagement means on the arm member for engaging and supporting the
post; and
(d) biasing means for biasing the arm member toward the post driver to
maintain the engagement means in supporting engagement with the post.
2. A post driver safety latch as defined in claim 1, wherein the engagement
means
comprises a roller.
3. A post driver safety latch as defined in claim 1, wherein the biasing means
comprises an over-center apparatus.
4. A safety latch for supporting a post inside a post driver, comprising:
(a) mounting apparatus secured to the post driver;
(b) a lever arm mounted on the mounting apparatus for pivotal movement
between a released position and a working position;
(c) post engagement apparatus movable with the lever arm between a released
position and a working position in supporting engagement with the post;
and
(d) a spring biasing the arm member toward the working position to maintain
the post engagement apparatus in supporting engagement with the post.
5. A safety latch as defined in claim 4, further comprising an over-center
apparatus
wherein the spring biases the lever arm toward the released position when the
lever arm
is on a first side of the center position and toward the working position when
the lever
arm is on the other side of the center position.
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Description

CA 02524962 2005-10-28
POST DRTVEIZ SAFETY LATCH
This application claims priority to United States Patent Application Serial
No.
60/623,325, filed October 29, 2004.
Background of the Invention
The invention relates generally to post drivers and, mote specifically, to a
safety
device for a hydraulic post driver.
Hydrauic post drivers are used in the setting and driving of posts into the
ground.
The drivers are usually carried on a prime }nover, such as a truck,
agricultural tractor, or
the like. The prime mover transports the driver to the desired position and
then uses
pressurized hydraulic clued from the prime. mover to drive the post into the
ground. An
example of a hydraulic post driver is described in U.S. Patent No. 2,940,267,
which is
incorporated herein by this reference.
Even though warned to use a tool or similar device to hold the post, if
needed,
while using the post driver, users would sometimes igaore the warnings and use
their
1S hands to hold or steady the post. The present device holds the post in
posifiion and will
reduce the likelihood that a user will endanger himself while using the post
driver.
Summary of the Invention
A hydraulic post driver includes a frame inside of which the post is
positioned in
a vertical orientation during the driving procedure. A hydraulic ram is
supported above
the frame and presses against the top of the; post to drive it into the
ground. Because the
frame must be open to receive the post, there is a possibility that the post
can be displaced
from the frame during the driving procedure: The invention consists of a
support that
holds a post in position relative to a post driver during the post driving
procedure.
The support is mounted on the frame adjacent the top end section. It includes
an arm
member that is mounted for swinging movement about a vertical axis of the
support
between a released position swung away from the frame and a working position
swung
toward the frame. A post-engaging roller is mounted on the arm member and is
brought
into and out of supporting engagement with the post as the arm member is swung
toward
and away from the frame. A spring-loaded, over-center device biases the roller
into
supportinng contact with the post as it is being driven into the ground. After
the post has

CA 02524962 2005-10-28
been driven into the ground, the arm member is swung away from the frame to
open the
frame for insertion of another post to be driven.
Brief Description of the Fi~.tres
Fig. 1 is a front elevational view of the invention shown holding a post in
position
for driving by a post driver.
Fig. 2 is an upper perspective of the invention in its open position.
Fig. 3 is an enlarged front view of the invention in its closed or working
position
holding a post.
Fig. 4 is a top view of the invention in its open position.
Fig. 5 is a top view of the invention in its shown in an intermediate position
between it open and closed posifiions.
Fig. 6 is a top view of the invention in its closed position.
Description of the Invention
Illustrated in Fig. 1, generally at 10, it the post support of the present
invention
shown mounted on a frame 12 of a post driver inside of which is shown a post
14. Above
the frame 12 is a hydraulic cylinder 16 that contacts the top of the post 14
to drive it into
the ground.
The post support 10 is shown in its open or released position in Figs. 2 and
4. It
includes a plate 18 mounted to a side of the frame 12. An arm member 20 is
mounted to
the plate 18 for swinging pivotal movement about an axis defined by a pin 22.
The arm
member 20 includes a first section 24 and a second section 26. A post-engaging
roller 28
is supported centrally on the arm member 20 approximately at the junction
between the
two sections. The free end of the second section 26 includes a handle 30 that
is grasped
by a user when swinging the arrn member 20.
A spring 32 interconnects the first section 24 and the plate 18 at a position
rearwardly of the pin 22. The spring 32 biases the arm member 20 toward its
mounting
on the plate 18. A stop 34 is provided that holds the arm member 20 in its
released
position as shown in Figs. 2 and 4 against further movement by the spring 32.
2

CA 02524962 2005-10-28
1n use to engage and support the post 14, the arm member 20 is pivoted toward
the frame 12 to bung the roller 28 into supporting contact engagement with the
post 14,
as illustrated in Figs. 1, 3, and 6. The spring 32 biases the arm member 20
and associated
roller 28 toward the post 14 once the arm member 20 has been pivoted toward
the post 14
bringing the attachment point of the spring 32 on the first section 24 past
the pivot axis as
defined by the pin 22. Accordingly, the spring 32 acts as an over-center
device. An
intermediate posifion is illustrated in Fig. 5, wherein the arm member 20 is
approaching
the center position.
In use, the post driver is moved to the desired position and a post 14 is
inserted
into the frame 12. The arm member 20 is pivoted from the open position (Fig.
4) through
the intermediate position (Fig. 5) to its post engaging position wherein the
roller 28 is in
contact with the post 14 (Fig. 6). Thereafter, as the post 14 is driven into
the ground, the
post support I O serves to hold the post 14 in the desired position within the
frame 12,
with the rnller 28 rolling along the surface of the post 14. After fihe post
14 h,as been
driven, the arm member 20 is pivoted to its released or open position so that
the post
driver can be moved to the next working location.
The foregoing description and drawings comprise illustrative embodiments of
the
present inventions. The foregoing embodiments and the methods described herein
may
vary based on the ability, experience, and preference of those skilled in the
art. Merely
listing the steps of the method in a certain order does not constitute any
limitation on the
order of the steps of the method. The foregoing description and drawings
merely explain
and illustrate the invention, and the invention is not limited thereto, except
insofar as the
clainns are so limited. Those skilled in the art who have the disclosure
before them will
be able to make modifications and variations therein without departing from
the scope of
the invention.
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