Fire escape – ladder – or scaffold – Horizontal traversing - actuation – control – or response – Holding means
Reexamination Certificate
2002-03-02
2004-02-10
Lev, Bruce A. (Department: 3634)
Fire escape, ladder, or scaffold
Horizontal traversing - actuation, control, or response
Holding means
C182S015000, C182S107000, C182S180100, C248S238000
Reexamination Certificate
active
06688426
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to ladders and, more specifically, to an extendable/retractable device for moving A-frame type stepladders. The device consists of four mechanisms providing means for extending/retracting wheel elements, one mechanism for each leg of the ladder and two control mechanism, each attached to a pair of leg mechanisms. When the handles of the control mechanisms are squeezed, the wheels are extracted until engaging the ground whereupon continued pressure applied to the control mechanism raises the ladder, enabling the user to move the ladder from point “A” to point “B” without physically lifting, closing or dragging the ladder.
The design consists of four retractable wheels positioned within a housing, one on each leg of the ladder and two grip handles attached to the wheels by a length of line. When the handles are squeezed the line contracts pulling the wheels along a gear face until they extend below the housing and raising the ladder enabling the user to move the ladder from point “A” to point “B” without lifting the ladder, closing the ladder or dragging the ladder.
A guide rack assembly is provided and includes; a rack, pulley, pinion, swivel wheel, pin, cable adjustment and rack guide. The rack gear is driven by the pinion gear which is a part of the pulley. When the handle is activated, the pulley and pinion gear move the rack gear and wheels in a downward motion. When the handle is released, a spiral spring located on the opposite side of the pulley releases the tension built on it when the cable was activated, causing the pinion gear to move the rack gear into its stored position.
2. Description of the Prior Art
There are other ladder devices designed for moving ladders. Typical of these is U.S. Pat. No. 1,293,066 issued to Faulkner on Feb. 4, 1919.
Another patent was issued to Mayberry on Apr. 11, 1950 as U.S. Pat. No. 2,503,626. A patent was issued to Fredericks et al. on Dec. 14, 1976 as U.S. Pat. No. 3,997,024. Yet another U.S. Pat. No. 4,063,616 was issued to Gutierrez on Dec. 20, 1977 and still yet another was issued on May 15, 1984 to Giezendanner as U.S. Pat. No. 4,448,282.
Another patent was issued to Kuperman on Mar. 27, 1990 as U.S. Pat. No. 4,911,263. Yet another U.S. Pat. No. 5,464,071 was issued to Rice et al. on Nov. 7, 1995. Another was issued to Gugel et al. on Dec. 17, 1996 as U.S. Pat. No. 5,584,357 and still yet another was issued on Jan. 7, 1997 to High et al. as U.S. Pat. No. 5,590,739.
Another patent was issued to Bendickson et al. on Aug. 5, 1997 as U.S. Pat. No. 5,653,306. Yet another U.S. Pat. No. 6,039,147 was issued to Gillis et al. on Mar. 21, 2000. Another was issued to Bieszczad on Oct. 23, 2001 as U.S. Pat. No. 6,305,496.
U.S. Pat. No. 1,293,066
Inventor: Albert N. Faulkner
Issued: Feb. 4, 1919
This invention relates to improvements in and relating to ladder feet, and has for its object to provide a device that attaches to a ladder as a non-slipping device.
U.S. Pat. No. 2,503,626
Inventor: Robert Mayberry
Issued: Apr. 11, 1950
The present invention relates to ladders and more particularly, to improve means for adjustably connecting ground engaging legs to the stiles of the ladder.
U.S. Pat. No. 4,063,616
Inventor: Ernest F. Gutierrez
Issued: Dec. 20, 1977
A safety ladder assembly having a plurality of steps and at least three support feet for supporting the ladder on a horizontal surface. A caster assembly having at least three casters for providing for rollingly transporting the ladder from one location to another. The casters are positively and conjointly moveable between a retracted storage position in which the support feet stably support the ladder on a horizontal surface and a second transporting position in which the casters stably support the ladder assembly on the horizontal surface with the support feet elevated thereabove so that the ladder assembly may be rollingly transported along the surface. A linkage interconnects the casters so that they may be raised and lowered via actuating and retracting pedals.
U.S. Pat. No. 4,448,282
Inventor: Ruedi Giezendanner
Issued: May 15, 1984
The ladder includes two separate ladder elements, which are pivotable and slidable relative to each other and can also be completely separated from each other. It can be used as a step-ladder and as a leaning type ladder. The ladder element is equipped with wheels, in order to simplify the transport of the collapsed ladder. In addition, an outwardly pivotable support plate is arranged between the wheels, so that the ladder element can serve as a hand truck, whereby the bent ends of the side beams serve as hand grips. The ladder has a simple construction and can be used in many ways in household use and in commercial operations.
U.S. Pat. No. 4,911,263
Inventor: Aryeh Kuperman
Issued: Mar. 27, 1990
Ambulatory ladder apparatus constructed as a stepladder frame supported on a set of four base wheels. A user-powered drive is mounted under the lowermost step of the ladder, and is mechanically connected with a pair of the base wheels. A drive arm extending from the drive is accessible to a user while aboard the stepladder. By pumping action of the drive arm, the user-powered drive causes rotation of the base wheels, moving the ladder forward. A steering mechanism provided on the drive arm allows the user to direct the motion of the ladder during the pumping action. Thus, without requiring the user to dismount, the ladder may be easily repositioned by operation of the drive, allowing greater work efficiency in many repair, remodeling, painting and construction projects, by eliminating the additional time normally required for dismounting and repositioning the ladder.
U.S. Pat. No. 4,911,263
Inventor: Aryeh Kuperman
Issued: Mar. 27, 1990
A portable collapsible scaffold ladder has a pair of upright caster-mounted end members joined together by a horizontal platform member. A pull-out ladder for scending to the platform is connectable at its upper end and sliable along its connected end member for movement between a nested position within that end member and a diagonally extending operative position. The platform member is joined to the two end members by T-shaped glide members pivoted to each of the four corners of the platform member. Each glide member has a glide portion slidable along one side of a connected end member and a pivot portion pivoted to an adjacent side portion of the platform member. Each glide member has a resilient leaf-type spring which carries two locking pins, one for interlocking with the platform and the other for interlocking with one of a series of pin-receiving openings in the upright. When the pins are engaged, the glide members rigidly interlock the platform member and two end members at right angles for use, or in parallel collapsed relationship for transport. When one pin of each pair of glide members is disengaged, the platform can be moved along the adjacent end member. When the opposite pin of each pair of glide members is disengaged, the platform and end members can be freely pivoted with respect to one another.
U.S. Pat. No. 5,464,071
Inventor: Crispin J. Rice et al.
Issued: Nov. 7, 1995
A new and improved ladder leveling device comprising a gear box having a plurality of gears coupled to an interior of the gear box on shafts. The shaft of a lowest gear extends outwardly of the gear box. A crank couples with the outwardly extending shaft of the lowest gear. The crank serves to rotate the lowest gear thereby collectively rotating the plurality of gears. A pin selectively couples with an uppermost gear and extends outwardly of the left wall. The pin serves to selectively engage or disengage the three gears. A plate is secured to a lower portion of the gear box. The plate serves to support the ladder's leg. Included in the device is a vertical rack having a plurality of teeth thereon. The vertical rack is secured within the gear box. The plurality of teeth engage the plurality of gears and are optionally raised or lowered by the rotat
Kroll Michael I.
Lev Bruce A.
LandOfFree
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