AERIAL WORK PLATFORM AND PINLESS GUARDRAIL
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.
Latest CALIFORNIA MANUFACTURING & ENGINEERING COMPANY, LLC Patents:
This application claims priority from our Provisional patent application Ser. No. 61/216,558 filed May 19, 2009.
BACKGROUND OF THE INVENTION AND PRIOR ART1. Field of the Invention
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.
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.
2. Description of the Related Art
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.
SUMMARYThe 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.
As used herein, the terms horizontal and vertical are general expressions not strictly limited to 0° and 90° orientations and relate to the positions occupied when the apparatus is on a generally horizontal surface with the guardrail sections in operative (vertical) position.
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.
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
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
As described above with reference to
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.
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.
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.
Type: Application
Filed: May 12, 2010
Publication Date: Nov 25, 2010
Applicant: CALIFORNIA MANUFACTURING & ENGINEERING COMPANY, LLC (KERMAN, CA)
Inventors: Gary Crook (Visalia, CA), Aaron Posner (Fresno, CA)
Application Number: 12/778,138
International Classification: E04G 5/14 (20060101); E04H 17/14 (20060101);