Harvesters – Motorized harvester – With selective control of drive means
Reexamination Certificate
1998-06-30
2001-03-13
Bagnell, David (Department: 3671)
Harvesters
Motorized harvester
With selective control of drive means
C056S011400
Reexamination Certificate
active
06199354
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to self-propelled, walk-behind power tools, such as lawn mowers, snow blowers or power sweepers, or like equipment. More particularly, the invention relates to a parking brake organization, especially of the foot operated type, utilizable in equipment in which each drive wheel of a power tool is individually braked.
2. Description of the Related Art
Although the present invention has utility in walk-behind snow blowers, power sweepers, or the like, the most common utilization of the invention is anticipated for lawn mowing equipment of the concerned type, and particularly, in large capacity, commercial walk-behind mowers. Consequently, except where otherwise expressly stated, the description herein is directed to walk-behind lawn mowing equipment, particularly commercial-type lawn mowers.
Commercial-type, self-propelled, walk-behind lawn mowers commonly have a power deck containing two driven wheels and handle bars mounting the operating handles for the various mower control elements. The mower-or tool-deck, which connects with the power deck, carries idler or caster wheels to support and balance it. Each drive wheel is independently operated and includes independent brake means dedicated to each drive wheel. Desirably, parking brake means are also provided to simultaneously lock the operating members for the brakes for both drive wheels when the mower is to be maintained in a prolonged stationary position.
Parking brakes for power tools of the concerned type are well known. Such apparatus is shown and described in U.S. Pat. No. 4,558,558 to H. F. Homer, Jr. et al. and U.S. Pat. No. 5,692,366 to T. D. Hardesty. The parking brake apparatus disclosed in these patents both suffer from the disadvantage that the elements operative to simultaneously hold both wheel brakes in a locked condition are located on the handle bars, or on one or more of the control elements carried by the handle bars. The disposition of parking brake operating apparatus on the handle bars of the mower adds further congestion to an already congested region of the mower and renders the parking brake operating apparatus, as well as other mower operation control elements disposed on or about the handle bars, difficult or inconvenient to access.
It is to the amelioration of this problem, therefore, to which the present invention is directed.
SUMMARY OF THE INVENTION
The present invention provides a self-propelled, walk-behind lawn mower containing foot-operated parking brake apparatus operative to simultaneously lock both of a pair of independently operated wheel brakes by depressing a foot pedal which is positioned remotely from the collection of mower operating controls disposed on the handle bars to a position that is readily accessible by the operator's foot.
Accordingly, there is provided by the present invention a self-propelled, walk-behind power tool comprising a bed; a power source and a power train drivingly connecting each drive wheel to the power source; a brake operatively associated with each drive wheel; a brake operator including a lever secured for pivotal movement to the bed and being effective to activate each brake to a braked condition with respect to the associated wheel when the lever is pivoted in one direction, and to a released condition when the lever is pivoted in an opposite direction; and parking brake means for securing the levers for both of the drive wheels in a braked condition, including pawls attached to each lever, an operating shaft journalled to the bed for rotational movement, an activating pedal fixed to the operating shaft for rotating the shaft, a pair of locking fingers containing locking teeth engageable with the pawls and disposed at axially spaced locations along the operating shaft in proximity to the respective pawls, at least one of the locking fingers being angularly displaceable on the operating shaft, and resilient means connecting at least one locking finger to said operating shaft.
Preferably, the resilient means that connects the one locking finger to the operating shaft comprises a torsion spring, the opposite ends of which operatively engage such locking finger and the operating shaft, respectively. In the preferred embodiment, one of the pair of locking fingers is fixed to the operating shaft for angular movement therewith. The other locking finger is movable with respect to the operating shaft, being operatively connected thereto by the torsion spring.
Moreover, in the disclosed form of the invention, in order to reduce the demands for close manufacturing tolerances in the production of the device, the fixed locking finger is angularly displaced from alignment with the movable locking finger by an amount enabling the movable locking finger to engage its associated locking pawl prior to engagement occurring between the fixed locking finger and its pawl.
It is accordingly a principle object of the present invention to provide a lawn mower of the concerned type in which the operating controls are free of congestion and easily accessible by the machine operator.
It is a further object of the invention to provide a parking brake apparatus for such lawn mower which is compact, structurally simple and inexpensive to produce, yet effective to simultaneously lock both of a pair of independently operated mower drive wheels.
For a better understanding of the invention, its operating advantages and the specific objectives obtained by its use, reference should be made to the accompanying drawings and description which relate to a preferred embodiment thereof.
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King Kevin D.
Ross Tony W.
Turk Daniel J.
Aodie Raymond W.
Armstrong, Westerman Hattori, McLeland & Naughton
Bagnell David
Honda Giken Kogyo Kabushiki Kaisha
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