U.S. patent number 3,839,824 [Application Number 05/340,232] was granted by the patent office on 1974-10-08 for removable safety guard for loading docks and platforms.
This patent grant is currently assigned to Lawrence D. Ellis, Ellis Industries. Invention is credited to Lawrence D. Ellis, Laurence H. Sheetz.
United States Patent |
3,839,824 |
Ellis , et al. |
October 8, 1974 |
REMOVABLE SAFETY GUARD FOR LOADING DOCKS AND PLATFORMS
Abstract
A removable safety guard for loading docks, platforms and the
like. The opposite ends of a flexible plastic cable are attached to
an enclosed spring-loaded reel in which they are retracted when not
in use. The reel enclosure is mounted on a main post disposed
adjacent to one side of the protected area. A cable pull is used to
unwind the cable from the reel and attach it to a terminal post
disposed adjacent to the other side of the protected area. The
cable provides two vertically spaced lengths of cable extending
across the protected area. For larger widths, a removable
intermediate post may be used.
Inventors: |
Ellis; Lawrence D. (Monrovia,
CA), Sheetz; Laurence H. (Monrovia, CA) |
Assignee: |
Lawrence D. Ellis, Ellis
Industries (South El Monte, CA)
|
Family
ID: |
23332441 |
Appl.
No.: |
05/340,232 |
Filed: |
March 12, 1973 |
Current U.S.
Class: |
49/34; 49/9;
242/378 |
Current CPC
Class: |
E01F
13/04 (20130101) |
Current International
Class: |
E01F
13/00 (20060101); E01F 13/04 (20060101); E01f
013/00 () |
Field of
Search: |
;49/34,9 ;256/35,37,1
;254/51,64,161,163,175.7,169 ;242/107.11,107.12,107.13,100.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Taylor; Dennis L.
Attorney, Agent or Firm: Comstock; Robert C.
Claims
We claim:
1. A safety guard for loading docks, platforms and the like
comprising a spring-loaded reel rotatably mounted adjacent to one
side of the area to be protected, a cable having a pair of ends
connected to said reel, said reel having a central circular hub,
both ends of said cable being wound around said hub from opposite
directions in overlying relationship to each other, said reel
having sides extending radially outwardly from said hub a
sufficient distance to hold said cable on said reel when said cable
is fully wound on said reel, a cable pull connected to said cable
remote from said ends, said cable pull being manually movable away
from said reel to unwind both ends of said cable from said reel
simultaneously, and means engageable with said cable pull to hold
said cable against retraction on said reel, said cable when
extended from said reel providing a pair of vertically spaced
lengths of cable extending across the area to be protected.
2. The structure described in claim 1, said reel being mounted on a
vertically directed main post, said reel being mounted for rotation
about a horizontal axis, a terminal post spaced from said main post
along the area to be protected, said cable pull being engageable
with means on said terminal post to prevent the retraction of said
cable.
3. The structure described in claim 2, said reel being rotatably
mounted within a reel enclosure, said reel enclosure being mounted
on said main post, and guide means disposed within said reel
enclosure for guiding the ends of said cable to and from said reel
and for vertically separating said cable lengths from each other
when said cable is extended, said guide means comprising a pair of
arcuate right angular guide tubes disposed adjacent to the top and
bottom of said reel enclosure, said cable ends slidably extending
through said guide tubes.
4. The structure described in claim 3, and an intermediate post
removably mounted between said main and terminal posts, said
intermediate post having means for slidably receiving both lengths
of said cable, and socket means disposed adjacent one of said first
named posts for storing said intermediate post when not in use.
5. The structure described in claim 3, said cable pull comprising
an elongated U-shaped tubular member approximately equal in length
to the distance between said cable lengths when said cable is
extended, said cable comprising a single length of cable slidably
extending through said cable pull and having its opposite ends
connected to said reel.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a removable safety guard which is
particularly adapted for use on loading docks, platforms, runways
and the like.
2. Description of the Prior Art
Truck docks and other work and loading platforms have always been
faced with difficult safety problems. At the present time, one
common type of protective device which is in use comprises a rigid
pipe railing. The pipe railing is normally fabricated on the job
site in three foot long sections, which are inserted in pipe
sockets in the platform. Longer pipe railing sections tend to bind
when being pulled out of or inserted into the sockets, so several
shorter sections are used. These sections of rail, when not in use,
must be stored out of the way. They are usually leaned against a
wall or a column of the building. A person bumping the stack of
rail sections or passing at the wrong time may have them fall,
causing possible injury.
Another type of protective device is a chain or cable railing,
which is usually fixed at one end and removably hooked at the other
end. When the railing is opened for work, there is always a pile of
loose chain or cable for personnel to trip over. Another problem
with cable is that it may fray, so that hands can be injured.
The various devices and expedients which are now in use accordingly
create almost as many safety problems as they solve. They are
expensive, difficult and awkward to use and do not provide an
acceptable answer to the problems of dock and platform safety for
personnel, equipment and cargo.
SUMMARY OF THE INVENTION
The invention provides a removable safety guard for loading docks
and platforms which overcomes all of the problems presented in
previous devices. In essence, the invention contemplates a flexible
plastic cable which is mounted on an enclosed spring-loaded reel on
which it is retracted when not in use. When extended, the cable
provides two vertically spaced lengths of cable removably attached
to a fixed or removable vertical post located on the opposite side
of the area being protected. A removable intermediate post may also
be used.
When the device is in use, the dock or loading platform is
protected and guarded as completely and effectively as by the rigid
railings, chains or cables previously used. On the other hand, when
the device is not in use all of the parts are easily and
conveniently stored completely out of the way of personnel,
equipment and cargo. Complete safety is accordingly provided.
The device provides with a minimum number of parts and
manufacturing variations a removable safety guard system which can
be used on substantially every type or size of loading platform or
dock.
The device of the present invention is more economical to
manufacture and is also more economical to use because it requires
only a short time to place in use or to remove from use.
The cable utilized by the invention is more visible than the prior
art devices, will not injure hands, will not absorb moisture or rot
and will not stretch or sag. It is substantially permanent but can
easily be replaced if the need should arise.
If removable posts are used, storage means are provided so that
safety hazards are eliminated. There are no loose parts lying
around to trip over or run over and no parts which can fall and
cause injury.
It is accordingly among the objects of the invention to provide a
removable safety guard for loading docks, platforms and the like
having all of the advantages and benefits set forth above and
described hereinafter in this specification.
The invention also comprises such other objects, advantages and
capabilities as will later more fully appear and which are
inherently possessed by the invention.
While there are shown in the accompanying drawings preferred
embodiments of the invention, it should be understood that the same
are susceptible of modification and change without departing from
the spirit of the invention .
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view on a reduced scale of a safety
guard in use on a loading dock, with the possible positioning of a
second cable reel shown in phantom lines;
FIG. 2 is a sectional view of the cable reel assembly taken on line
2--2 of FIG. 1;
FIG. 3 is another sectional view of the same, taken on line 3--3 of
FIG. 2;
FIG. 4 is a partial sectional view taken on line 4--4 of FIG.
3;
FIG. 5 is a partial sectional view of the upper cable receiving
sleeve in the intermediate post;
FIG. 6 is a partial sectional view of the pull, showing in
elevation the flange for removably attaching the pull to the
terminal post;
FIG. 7 is a transverse sectional view taken on line 7--7 of FIG.
6;
FIG. 8 is a front elevational view showing two reels in use on a
loading dock connected to opposite sides of a central terminal
post.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment which has been selected to illustrate the
invention is adapted to be used on substantially any type of truck,
railroad, ship or airline loading docks, platforms, open sided
floors, runways, etc. It may also be used for wall openings in
warehouses, factories, etc. or any other place where a safety
problem exists.
A vertically directed main post 10 is customarily permanently
installed in the floor adjacent to one side of the platform 11 or
other dock or wall opening being protected. The post 10 may be
formed of any suitable material. Two inch square structural steel
tubing has been found particularly satisfactory. The top of the
post 10 is preferably closed by a rubber guard 10a to prevent
personal injury and protect the interior of the post from debris
and moisture.
Mounted on the top of the main post 10 is a reel enclosure 12,
which may conveniently be formed of molded fiberglass material or
other plastic or metal material. Rotatably mounted within the reel
enclosure 12 is a spring-loaded reel 13 of a conventional type
which is available as a product of standard manufacture and which
is well known in the art. A reel 13 having a diameter of 12 inches
has been found satisfactory in use. The reel 13 is normally urged
in one direction by an internal spring 14 and can only be rotated
in the opposite direction against the urging of the spring 14.
A pair of diametrically opposed U-bolts 15 or other suitable
anchoring devices, extend through one side of the reel 13, with
their closed ends disposed on the inside of the reel. Extending
beneath the closed ends of the U-bolts 15 are the opposite ends of
an elongated cable 16, which may be formed of any suitable
material. Twisted polypropylene having a 1/2 inch diameter with
high tensile strength and an easily visible yellow color has been
found particularly satisfactory in use. Such line has a tensile
strength of 4,400 lbs.
Each of the U-bolts 15 has a pair of threaded legs which are
disposed on the outside of the reel. Nuts threaded thereon may be
loosened to release the U-bolts 15 and permit longitudinal
adjustment of the length of the cable 16.
Within the top and bottom of the reel enclosure 12 are a pair of
right angular cable receiving guide tubes 17, which may
conveniently be formed of metal. The ends of the cable 16 extend
from the reel 13 through the guide tubes 17, the ends of which
extend through openings in the front of the reel enclosure 12.
The guide tubes 17 are circular in cross section and their sides
are welded to flanges 18 which are in turn welded to the inside of
the back wall of the reel enclosure 12. The guide tubes 17 act to
direct the cable 16 to and from the reel 13 and prevent its
opposite ends from becoming entangled.
The guide tubes 17 are fixed, but the reel 13 is rotatably mounted
on a shaft 19 which extends transversely through the reel enclosure
12 and the main post 10. The bolt 20 which extends through the
front of the reel enclosure 12 and into the end of the shaft 19 may
be removed to permit removal of the front cover portion of the reel
enclosure 12 to provide access to the interior. The reel 13 has a
central circular hub 21, which encloses the spring 14. Both ends of
the cable 16 wind around the hub 21 in opposite directions in
overlying relationship to each other as the reel 13 is rotated. The
sides of the reel 13 extend radially outwardly from the hub 21 a
sufficient distance to hold the cable 16 on the reel 13 when the
cable 16 is fully wound on the hub 21.
A terminal post 25, which may be formed substantially identical
with the main post 10, is mounted adjacent to the opposite side of
the area to be protected. A terminal post 25 may be either
permanently or removably mounted, as desired. The upper portion of
the terminal post 25 is provided with a pair of vertically spaced
outwardly projecting pins 26 which are disposed on one side of the
terminal post 25.
The center of the cable 16 extends through an elongated U-shaped
tubular cable pull 27, which may be formed of metal or other
suitable substantially rigid material. Extending outwardly from the
front edge of the pull 27 are a pair of flanges 28, each of which
is provided with a keyhole slot 29. The keyhole slots 29 are
dimensioned and arranged to removably receive and engage the pins
26 on the terminal post 25. The pull 27, flange 28 and keyhole
slots 29 are shown in FIGS. 6 and 7 of the drawings.
When the device is not in use, the cable 16 is fully wound around
the hub 21 of the reel 13 which is in turn disposed within the reel
enclosure 12. The pull 27 is disposed directly adjacent to the reel
enclosure 12, with its opposite ends abutting against the reel
enclosure 21 adjacent to and surrounding the openings through which
the guide tubes 17 extend.
The spring 14 of the reel 13 acts to normally hold the cable 16 in
fully retracted position and to hold the pull 27 in the position
described.
In order to place the safety guard in position for use, the user
need only exert sufficient force manually on the cable pull 27 to
move it away from the reel enclosure 12. As the pull 27 is moved
away from the reel enclosure 12, both ends of the cable 16 are
unwound from the hub 21 of the reel 13 and the reel 13 is rotated
against the urging of the spring 14. When the pull 27 reaches the
terminal post 25, the keyhole slots 29 of the flanges 28 are fitted
over the pins 26 on the terminal post 25 and return movement of the
pull 27 and cable 16 is prevented.
When removal of the safety guard is desired, the pull 27 is
detached from the terminal post 25 and the spring 14 will then
automatically rewind both ends of the cable 16 simultaneously,
moving the pull 27 back to its storage position adjacent to the
reel enclosure 12.
If the width of the area to be protected is 8 feet or less, only a
single main post and a single terminal post are required. If the
area to be protected is wider, an intermediate post 30 of the type
shown in FIG. 1 of the drawings may be used. The intermediate post
30 is normally removably mounted in a socket 32 formed in the
floor. The intermediate post 30 is formed similarly to the
previously described posts 10 and 25, but is provided with a pair
of transversely directed tubular sleeves 31 through which the cable
16 freely and slidably extends. The intermediate post 30 and upper
sleeve 31 are shown in FIG. 5.
In order to provide a clear working area when an intermediate post
30 is required, a storage socket 33 is provided adjacent to the
main post 10 (or terminal post 25). The intermediate post 30 may
thus be moved from its own socket 32 and stored in the storage
socket 33 when not in use.
In order to cover a larger area, a series of main and terminal, or
main, terminal and intermediate posts may be used in successive
series. This can easily be done by mounting a second reel enclosure
on the opposite side of the terminal post, as shown in phantom
lines in FIG. 1 of the drawings.
FIG. 8 of the drawings shows another alternative arrangement in
which a pair of main posts having reel enclosures are mounted on
opposite sides of the area to be protected, with both pulls being
connected to a single central terminal post, which may be
removable. Intermediate posts may also be used with this
arrangement, if required.
While any suitable dimensions may be used, it has been found for
the protection of personnel that a height of 21 inches from the
ground is satisfactory for the lower portion of the cable 16 and 42
inches from the ground for the upper portion of the cable.
* * * * *