U.S. patent application number 12/778138 was filed with the patent office on 2010-11-25 for aerial work platform and pinless guardrail.
This patent application is currently assigned to CALIFORNIA MANUFACTURING & ENGINEERING COMPANY, LLC. Invention is credited to Gary Crook, Aaron Posner.
Application Number | 20100294592 12/778138 |
Document ID | / |
Family ID | 42320825 |
Filed Date | 2010-11-25 |
United States Patent
Application |
20100294592 |
Kind Code |
A1 |
Crook; Gary ; et
al. |
November 25, 2010 |
AERIAL WORK PLATFORM AND PINLESS GUARDRAIL
Abstract
An aerial work platform and guardrail system having a deck which
may include a deck frame; vertically extending guardrail supports
affixed to the deck or deck frame; and guardrail sections at the
periphery of the deck. The sections have legs receivable in the
guardrail supports with spaced upper and lower guides affixed to
the legs, the guides being receivable in said guardrail supports
and having surfaces for engaging inner surfaces of the guardrail
supports. Retainers retain the lower guides in the guardrail
supports whereby the guardrail sections may be individually lifted
from a lower operative position to an upper pivot position at which
the sections are retained in the supports by engagement of lower
guides with the retainers and may be pivoted about the lower guides
to a horizontal position for storage.
Inventors: |
Crook; Gary; (Visalia,
CA) ; Posner; Aaron; (Fresno, CA) |
Correspondence
Address: |
W. NORMAN ROTH
18300 River Ford Drive
Davidson
NC
28036
US
|
Assignee: |
CALIFORNIA MANUFACTURING &
ENGINEERING COMPANY, LLC
KERMAN
CA
|
Family ID: |
42320825 |
Appl. No.: |
12/778138 |
Filed: |
May 12, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61216558 |
May 19, 2009 |
|
|
|
Current U.S.
Class: |
182/113 ;
256/59 |
Current CPC
Class: |
B66F 11/044
20130101 |
Class at
Publication: |
182/113 ;
256/59 |
International
Class: |
E04G 5/14 20060101
E04G005/14; E04H 17/14 20060101 E04H017/14 |
Claims
1. An aerial work platform and guardrail system comprising: a work
platform having a deck; vertically extending guardrail supports
affixed to said deck; and guardrail sections at the periphery of
said deck, said sections having legs receivable in said guardrail
supports, said guardrail supports each having a vertically
extending opening above and facing said deck, spaced upper and
lower guides affixed to at least some of said legs, said guides
being receivable in said guardrail supports, said guides being
spaced a length less than the vertically extending length of said
guardrail supports, said guides having contact surfaces engageable
with inner surfaces of said guardrail supports, and retainers for
retaining the lower ones of said guides in said guardrail supports
whereby said guardrail sections may be lifted from operative
position to an upper pivot position at which said sections are
retained in said supports by engagement of lower ones of said
guides with said retainers and may be pivoted about said lower ones
of said guides through said openings in said supports to a
horizontal position for storage.
2. The system of claim 1, wherein said contact surfaces of said
guides comprise flat or arcuate surfaces engageable with said
guardrail supports.
3. The system of claim 1, wherein said retainers comprise elongated
members affixed to and extending between spaced sides of said
guardrail supports.
4. The system of claim 2, wherein said elongated members comprise
removable threaded members.
5. The system of claim 4, wherein said lower ones of said guides
are rotatably affixed to said legs of said guardrail sections.
6. The system of claim 1, wherein said deck includes side and end
frame members having upper and lower horizontally extending
flanges, said guardrail supports having lower ends supported on
said lower horizontally extending flanges and said supports being
received in apertures or cutouts in said upper horizontally
extending flanges.
7. The system of claim 6, wherein said guides are made of
lubricious material.
8. A guardrail system for an aerial work platform comprising: a
plurality of guardrail supports for attachment in vertical
orientation to a deck frame of a work platform; at least one
guardrail section having legs receivable in said guardrail
supports, said guardrail supports comprising channels each having a
vertically extending opening facing said platform, spaced upper and
lower guides affixed to opposite sides of each of said legs, said
guides being receivable in said guardrail supports and being spaced
along said legs a length less than the length of said guardrail
supports, said guides having contact areas engageable with inner
surfaces of said guardrail supports, and retainers for retaining
the lower ones of said guides in said guardrail supports whereby
said guardrail section may be lifted from operative position to an
upper pivot position at which said section may be retained in said
supports by engagement of lower ones of said guides with said
retainers and may be pivoted about said lower ones of said guides
to a horizontal position for storage.
9. The system of claim 8, wherein said contact surfaces of said
guides comprise flat surfaces engageable with said guardrail
support.
10. The system of claim 8, wherein said retainers comprise
elongated members affixed to and extending between spaced sides of
said guardrail supports.
11. The system of claim 10, wherein said elongated members comprise
removable threaded members.
12. The system of claim 9, wherein said lower ones of said guides
are rotatably affixed to said legs of said guardrail section.
13. The system of claim 8, wherein said guides are made of
lubricious material.
Description
CROSS REFERENCE TO RELATED APPLICATIONS, IF ANY
[0001] This application claims priority from our Provisional patent
application Ser. No. 61/216,558 filed May 19, 2009.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0002] 1. Field of the Invention
[0003] Guardrails for aerial work platforms are mandatory for
safety and safety standards typically require that the guardrails
must resist a 300 lb outward force such that when leaned on, the
guardrail prevents a worker from falling and likely serious injury
or death. Typically, the guardrails are between 42'' and 45'' above
the deck and comprise a number of separate individual sections.
[0004] Aerial work platforms are moved to and from work positions
by extensible booms or scissor lifts which may extend to
significant elevations and, when lowered for transport or storage,
the work platform may still be high off the ground. Accordingly,
there is need to lower the guardrails particularly when the work
platform apparatus is loaded on a truck or trailer during transport
to minimize the height of the apparatus to safely clear bridges and
other obstacles. There is also occasional need to lower the
guardrails to gain access into buildings through low doorways.
[0005] 2. Description of the Related Art
[0006] Hinged guardrail sections are well known but require the use
of removable pins to retain the guardrail sections in both a
vertically extending work position and in a horizontally extending
storage position. The retainer pins are frequently dropped or lost
during transport or work conditions and, for this reason, lanyards
or other pin retainers are ordinarily used. Time consuming and
tedious removal of the pins is required when raising or lowering
the guardrail sections and worker frustration is compounded by
having to hold the guardrail section with one arm while installing
or removing pins with the other, a particularly difficult task when
the machine is positioned on a slope.
SUMMARY
[0007] The system disclosed herein comprises: a work platform
having a deck; vertically extending guardrail supports affixed to
the deck; and guardrail sections at the periphery of the deck. The
guardrail sections have legs receivable in the guardrail supports
which may comprise channels having open sides facing the deck.
Spaced upper and lower guides not unlike hockey pucks are affixed
to the guardrail legs, and the guides are receivable in the
guardrail supports and are spaced from each other a length less
than the length of the guardrail supports. The guides have contact
surfaces engageable with inner surfaces of the guardrail supports.
Retainers retain the lower guides in the guardrail supports whereby
the guardrail sections may be lifted from operative position to an
upper pivot position at which the guardrail sections are retained
in the supports by engagement of the lower guides with the
retainers. The guardrail sections may be pivoted about the lower
guides to a horizontal position for storage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a rectangular aerial work
platform having guardrail sections at its sides and ends showing
one section horizontally positioned for storage.
[0009] FIG. 2 is an enlarged partial perspective view of one side
of the work platform showing guardrail supports.
[0010] FIG. 3 is an enlarged horizontal cross section taken at line
3-3 in FIG. 2 showing guardrails in the operative position engaged
with the guardrail supports.
[0011] FIG. 4 is a partial perspective view showing guardrail legs
positioned in the guardrail supports.
[0012] FIG. 5 is a partial perspective view showing guardrails legs
lifted partially out of the supports for later folding to a
horizontal storage position.
[0013] FIG. 6 is a partial perspective view showing the guardrail
legs folded to a horizontal storage position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] As used herein, the terms horizontal and vertical are
general expressions not strictly limited to 0.degree. and
90.degree. orientations and relate to the positions occupied when
the apparatus is on a generally horizontal surface with the
guardrail sections in operative (vertical) position.
[0015] FIG. 1 is a perspective view of an aerial work platform and
guardrail system suitable for use with a scissors or boom type
lift, not shown. The work platform 10 includes a deck 12. The deck
12 may be supported on a generally rectangular deck frame 14
comprising structural members which, as seen in FIG. 2, have spaced
upper and lower inwardly extending horizontal flanges 16, 18 which
face the work platform. In the embodiment shown in FIG. 1, two
elongated guardrail sections 20, 22 are used at either long side of
the deck 12. One short side of the deck is provided with a single
guardrail section 24 and the other short side of the deck of the
platform is provided with three separate guardrail sections 26 -
28, the center one 27 of which is an entry section or vertically
liftable gate.
[0016] Each guardrail section has at least two legs 30, 32 and a
pair of generally horizontally extending guardrail members 34, 36
extending between the legs. Tubular metal stock is generally used
for construction of the guardrail sections and guardrail supports
more fully described below. The lower ends of each leg are
receivable in generally vertically extending guardrail supports 40
affixed to the deck or deck frame. The supports 40 preferably
comprise channel sections having open sides facing the deck 12 of
the work platform. The guardrail supports 40 may also be formed of
rectangular or square cross-section stock so long as the supports
each have a vertically extending opening above and facing the
deck.
[0017] Spaced upper and lower guides 50, 52 are affixed to
laterally opposite sides of each of the legs of the guardrail
sections and are closely receivable in the guardrail supports 40.
The guides have a width or diameter approximately the same as the
width of the legs 30, 32 with the lower guides 52 positioned at the
lower ends of the legs 30, 32. The guides are vertically spaced
from each other a length which is preferably only slightly less
than the vertical extent of the guardrail supports 40 so as to
provide the greatest stability for the guardrail sections when the
sections are positioned in vertically extending operative position.
The guides 50, 52 have contact surfaces which are engageable with
inner vertically extending surfaces of the guardrail supports 40.
The guides are sized such that the peripheral surface of the guides
will operatively engage facing inner surfaces (41 in FIG. 3) of the
guardrail supports 40 which are generally parallel to the long
direction of the deck and the exposed outer side surfaces of the
guides may engage inner surfaces of the supports 40 which extend
generally parallel to the short direction of the deck. The guides
50 and 52 are preferably hexagonal as seen in FIG. 5 or they may be
cylindrical about the size and shape of a hockey puck and are
preferably made of a lubricious material such as Nylon.
[0018] Guide retainers 54, 56, preferably in the form of elongated
threaded bolts and fastener nuts, retain the lower ones 52 of the
guides in the guardrail supports 40. The retainers are positioned
as shown in FIGS. 3 above the lower ones of the guides whereby the
guardrail sections may be lifted from the operative generally
vertically extending position to an upper pivot position at which
the sections are retained in the supports by contact of the lower
guides 52 with the retainers 54, 56 and such that the guardrail
sections may then be pivoted about the lower guides 52 to a
horizontal position for storage. See the arrows in FIGS. 1 and 2
indicating the lifting and pivoting of the guardrail sections to
storage position. As seen in FIG. 1, one guardrail section is
pivoted to the horizontal position. The upper and lower retainers
50, 52 are preferably rotatably attached by support axles to the
legs of the guardrail sections.
[0019] As described above with reference to FIG. 2, a typical deck
frame 14 will include side and end frame members in the form of
channel sections each having upper and lower horizontally extending
flanges 16, 18 whereby the guardrail supports 40 have their lower
ends in contact with and supported on the lower horizontally
extending flanges of the deck frame. The upper flanges of the deck
frame may be provided with apertures or cutouts to receive the
vertically extending guardrail supports 40.
[0020] The guardrail system disclosed above eliminates the
necessity for retention pins and associated lanyards or other
retainers to prevent loss of pins for securing the guardrail
sections in either vertically extending work or horizontally
extending storage positions. Guardrail systems comprised of
multiple guardrail sections and supports as disclosed herein can
readily be retrofitted to existing work platforms.
[0021] Those skilled in the art will understand that various
modifications of the preferred embodiments shown and described
herein can be made without departing from the scope of the
invention which is defined by the appended claims.
* * * * *