Fire escape – ladder – or scaffold – Ladder – Supporting surface compensating means
Reexamination Certificate
2001-03-20
2002-06-25
Chin-Shue, Alvin (Department: 3634)
Fire escape, ladder, or scaffold
Ladder
Supporting surface compensating means
Reexamination Certificate
active
06408984
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to ladder leveling devices and, more particularly, to a device for supporting and selectively tightening a leg of a ladder to a support sleeve and for selectively adjusting the vertical position of a ladder leg according to a sight level.
A common problem faced by persons using a ladder is placing the ladder upon a completely level support surface. When a level surface cannot be located, users too often attempt to prop up a ladder support leg with any available item, such as boards or bricks, or to simply use the ladder in an uneven configuration. Obviously, using a ladder in either of these instances is dangerous.
Various devices have been proposed in the art for leveling a ladder. Although assumably effective for their intended purposes, existing devices are typically required to be attached to a ladder with fasteners, do not adequately support a ladder leg, or still require the user to estimate the proper adjustment to make the ladder level.
Therefore, it is desirable to have a ladder leveling device that includes a platform that supports the foot of a ladder support leg and includes clamping arms for selectively tightening the support leg to the device. Further, it is desirable to have a ladder leveling device that includes a bubble-type sight level for establishing a proper device adjustment. Finally, it is desirable to have a ladder leveling device which requires no additional hardware for attachment to a ladder and which does not damage the ladder.
SUMMARY OF THE INVENTION
A ladder leveling device according to the present invention includes a generally rectangular support sleeve having a platform adapted to support a foot of a support leg of a ladder. The support sleeve further includes a pair of clamping arms for selectively tightening a ladder support leg to the support sleeve. Each clamping arm is slidably coupled to the support sleeve and integrally includes a rack gear. A crank handle is connected to a shaft that extends through an outer side wall of the support sleeve and is rotatably coupled to an inner side wall thereof. A pinion gear is mounted about the shaft and positioned for engagement with the clamping arm rack gears such that the clamping arms are concurrently moved in opposite directions upon a rotation of the crank handle.
The ladder leveling device further includes a leveler leg positioned for vertical movement within the support sleeve. Another rack gear is mounted to the leveler leg. Another crank handle is connected to a shaft that extends through the outer side wall of the support sleeve and is rotatably coupled to the inner side wall thereof. Another pinion gear is mounted to the shaft and positioned for engagement with the leveler leg rack gear such that rotation of the crank handle causes the rack and pinion gear assembly to move the leveler leg vertically relative to the support sleeve. Both rack and pinion gear assemblies include a pawl for holding the pinion gears in user-selectable positions, each pawl being releasable by a user from engagement with a respective pinion for allowing opposing movement of respective rack gears. A bubble-type sight level is mounted on the outer side wall of the support sleeve so that a user can determine if he has properly adjusted the leveler leg to place the ladder in a completely level configuration.
Therefore, a general object of this invention is to provide a device for leveling a ladder which may be attached to a support leg of a ladder without additional hardware or tools.
Another object of this invention is to provide a device, as aforesaid, which includes a platform for supporting the foot of a ladder support leg.
Still another object of this invention is to provide a device, as aforesaid, which includes clamp arms for selectively tightening a ladder support leg to a support sleeve.
Yet another object of this invention is to provide a device, as aforesaid, in which the tightness of the clamping arms or the vertical configuration of a leveler leg are adjustable with rack and pinion gear assemblies.
A further object of this invention is to provide a device, as aforesaid, in which the leveler leg includes a pivotal foot.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.
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Chin-Shue Alvin
Ream Dale J.
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