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US 4,362,004 AGranted
Brake and clutch mechanism
AssigneeMTD Products Inc
InventorsRobert W. Rush, Jr., Paul R. Fortlage
Life of this patent
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AssigneeMTD Products Inc
InventorsRobert W. Rush, Jr., Paul R. Fortlage
Estimating the term…
A brake and clutch mechanism for a rotary type lawn mower or the like in which first friction element (25) carried by a rotor member (24) is rotatable with the working element or blade (14) and is resiliently urged by springs (26) into clutching engagement with a clutch member (27) rotated by the driving shaft (13) of the mower, and in which second friction elements (32) are resiliently urged radially outward by springs (36) into braking engagement with a braking surface (24A) of said rotor member (24).
In a brake and clutch mechanism for a rotary type lawn mower having a motor mounted on the mower housing, a motor-driven shaft extending from the housing, and a cutting blade mounted on the free end of the shaft and adapted to be rotated by the shaft, the improvement comprising in combination, a rotatable carrying member concentrically mounted about said shaft adjacent the free end of the shaft and adapted to be secured to the blade to rotate with the blade, said rotatable member being unsecured to said shaft to be free to rotate independently of said shaft, a rotor member mounted to the rotatable carrying member to rotate therewith, a resilient member interconnecting said rotatable carrying member and said rotor member and biased to urge the said rotor away from said rotatable carrying member parallel to the axis of said shaft, a first friction element carried by the rotor member and movable therewith toward and away from said rotatable carrying member, a clutch cone member concentrically mounted about said shaft to rotate with said shaft, said clutch cone member having engaging surfaces aligned with said first friction element to clutchingly engage the friction element upon the said resilient member urging the said rotor member away from said rotatable carrying member, said rotor member having a braking surface movable with the rotor member about the axis of said shaft, a second friction element disposed to engage said braking surface of the rotor member, an arm member carried by the mower holding said second friction element, an actuating member for moving the arm member to shift the second friction element carried by the arm member into and out of braking engagement with the said braking surface to brake and unbrake the rotation of said rotor, said second friction element and said braking surface being disposed to face each other so as to impart to the rotor member a component of force which moves the rotor member toward the rotatable carrying member against the resilient urging of the resilient member upon the second friction element being moved into braking engagement with said braking surface to simultaneously terminate the clutching engagement of the rotor member and first friction element, in the engaged condition of the second friction element, the spacing between the said braking surface and the corresponding surface of the second friction element that is engageable by the said braking surface being different from the spacing between the clutch cone member and the corresponding surface of the first friction element that is engageable by the clutch cone member to assure a difference between the occurrence of the engagement of the second friction element with said braking surface and the occurrence of the engagement of the first friction element and the said clutch cone member.
In a brake and clutch mechanism of a machine for controlling the clutching and braking of a rotatable working tool driven by a rotatable engine-driven shaft, the improvement comprising in combination a rotatable member concentrically mounted about said shaft and rotatable with said working tool, the rotatable member being free to rotate about said shaft upon the mechanism being in unclutched condition, a rotor concentrically mounted about said shaft and carried by said rotatable member to rotate therewith, a first friction element carried by said rotor to rotate therewith about the axis of said shaft in a first plane normal to the axis of said shaft, a second friction element carried by the machine and disposed in a second plane parallel to the said first plane and spaced therefrom, a supporting member for supporting said second friction element, an actuating member connected to said supporting member for moving said supporting member for moving the second friction element in said second plane toward and away from the axis of said shaft, a resilient member inter-connecting said rotor and rotatable member and disposed to resiliently urge the rotor and first friction element carried thereby from said rotatable member toward said second plane, the said rotor having a first portion carrying said first friction element and movable therewith away from said rotatable member, the said rotor having a second portion carrying a braking surface, and a clutch part carried by and rotatable with said shaft and juxtaposed to said first friction element to be clutchingly engaged by the first friction element upon movement of the first friction element toward the said clutch part, the first and second portions of said rotor being so spaced apart that upon the second friction element being moved to brakingly engage the braking surface of the rotor, the rotor is moved away from said second plane to disengage said first friction element from the said clutch part for de-clutching the rotor, rotatable member, and working tool from said shaft.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Driving mechanisms: braking or clutching mechanisms
Combinations of couplings and brakes; Combinations of clutches and brakes: clutch-brake combinations
Lawn-mowers
Harvesting
Term ended 24 Nov 2000 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
Our invention relates to a brake and clutch mechanism particularly for the concurrent braking and declutching of a rotatable working element and for the concurrent unbraking and clutching of the working element. It is especially suitable for a rotary-type lawn mower so that the working element, the rotating blade, is braked against rotation at substantially the same time that the blade is declutched from the driving shaft of the mower motor and so that the blade is clutched to rotate with the shaft at substantially the same time that the blade is unbraked and permitted to rotate.
The related background art known to Applicants but which does not teach, disclose or suggest the present invention, includes the following U.S. Pat. Nos.: 3,871,159--Charles R. Shriver, 4,035,994--Stephen J. Hoff, 4,141,439--James M. Lunde et al, 4,148,173--Stephen J. Hoff, 4,205,509--Takeshi Miyazawa et al.
Also related to, but distinct from, this invention is the invention disclosed and claimed in co-pending U.S. Pat. application Ser. No. 174,861 filed Aug. 1, 1980 by Gerhard R. Plamper, and assigned to the owner of this present application.
FIG. 1 is a longitudinal sectional view taken through the improved brake and clutch mechanism and illustrating the parts in a clutched and unbraked condition;
FIG. 2 is a partial longitudinal sectional view similar to that on the right hand side of FIG. 1, but showing the parts in an unclutched and braked condition;
FIG. 3 is a plan view looking down on the lower portion of the mechanism, which lower portion is rotatable with the working element or blade;
The present invention is here described in connection with its use in a rotary type lawn mower having a motor driven blade for which use it is especially adapted, although it is also useful in connection with other machines having a motor driven rotatable working element. The best and preferred embodiment of the invention as presently known to the inventors is as herein disclosed.
The lawn mower to which the invention is here applied has a motor or engine 12, which may be an internal combustion type motor or an electric motor, which is mounted on a mower housing 11. A fragmentary portion of the housing 11 and motor 12 is shown in FIG. 1. Extending downwardly from motor 12 is an upright driving shaft 13 adapted to rotate parts carried thereby when clutched to the shaft.
A fan member 19 having a fan hub portion 19A is splined to the shaft 13 so as to rotate with the shaft. Secured to the lower end of the fan body 19A a bolt 17 is a bearing assembly 18. The mounting is such that the inner race of bearing assembly 18 is rotated by the fan body 19A and shaft 13 to which it is secured. The outer race of bearing assembly 18 is rotatable around the bolt 17 and fan body 19A and shaft 13, or conversely may remain stationary while the shaft 13, fan body 19A and bolt 17 may rotate.