US2142295A - Lawn mower - Google Patents

Description

' Jan. 3, 1939 c WILLFQRD 2,142,295

LAWN MOWER Original Filed May 5, 1956 GROVE/e 6f WILL-FORD,

mu L-JQ-I f 6 BY .4; 67 v ATTORNEK Patented Jan. 3, 1939 UNITED STATES PATENT OFFICE Application May 5, 1936, Serial No. 77,927 Renewed May 17, 1938 6 Claims. (01. 56-294) This invention relates to improvements in lawn-mowers.

One of the objects of my invention is to provide a lawn-mower of simple and practicable construction of the type now in general use in which the rotary cutter-blades are mounted upon an adjustable shaft through which the rotary cutting-reel may be raised or lowered in an arcuate path to determine the height at which the grass is to be out.

A further object of the invention is the provision in a lawn-mower of the class described of means for mounting the ledgerblade that is bodily adjustable in an arcuate path approximately corresponding to the limits of adjustment of the cutting-reel above set forth, together with means for tiltably adjusting the same to produce the desired shearing angle between the blades desired throughout the entire range of adjustments to which the cutting-reel is subject.

Other objects and advantages residing in my invention, and objects relating to details of construction and various arrangements of parts thereof, will be fully described in the detailed description to follow and finally set forth in the appended claims.

The accompanying drawing illustrates by way of example a representative form of my invention, in which:

Figure 1 is a top plan View of a lawn-mower embodying my invention.

Fig. 2 is a view in transverse section of the same.

Fig. 3 is a view on a radial section line upon an enlarged scale through a portion of a wheel and blade-actuating devices.

Fig. 4 is a detached perspective view of the ledger-blade and supporting-bar.

Fig. 5 is a fragmentary view in side elevation of a side-plate element of the invention, illustrating the mounting of the supporting-bar thereon.

Fig. 6 is a view in cross section of Fig. 5.

Referring to said views, the reference numeral iii indicates, the opposite side-plates of my improved lawn-mower, each comprising a circular body H and a rearward extension I2. A wheel I3 of larger diameter than the respective said plate-body is rotatably mounted upon the hubs i5 through axle-bolts [6. A transverse bar l'l rigidly secures said side-plates in operative spaced relation. Each said side-plate is formed with an integral housing I8 on its inner side having an interior chamber 20.

Adjacent the outer perimeter of said circular body an arcuate slot 2i is formed in said housing having outer and inner edges 22 and 23, respectively, formed concentric with the outer periphery of said body, and opposite terminal walls 25 substantially radial thereof. A block 26 is slid- 5 ably received in said slot .having its outer and inner faces 21 and 28 formed to the respective curvature of the slot- edges 22 and 23 and provided with overlying flanges 39 and 3! extending beyond said edges and bearing upon the 10 outer wall of the housing.

Each said block is formed with a medially disposed seat for an anti-friction bearing 32 extending therethrough in which an end of the shaft 33 of the rotary cutting reel is mounted. 5 The outer ends of said shaft are each provided with the usual ratcheted toothed pinion 35 meshing with an internal ring-gear 3% formed upon the interior of the wheel is and through which the cutting-reel is rotatively actuated on 0 each forward revolving movement of the wheels in the usual manner.

The cutting-reel comprises a plurality of spider-frames 31 rigid with the shaft 33 upon the exterior of which the curved cutting-blades 25 38 of the usual pattern are secured, the spiral cutting-edges l!) of said blades being set and ground throughout their lengths to the same radii relative to their axis of rotation. It will thus be evident that through the movement of the blocks 26 in the slots 25 the height of the circular sweep of the blades, as indicated by broken lines A in Fig. 2, with respect to the ground may be determined. To secure the cutting-reel in such adjusted position screws i! and 42 are screw-threaded through the end walls 25 and bear upon the opposite sides of the blocks. As a guide for setting the oppositely disposed blocks 26 to the same elevation similarly graduated marks it are formed along the inner edges 23, with which the lateral sides of the blocks may be selectively brought into similar register.

In each of the opposite plate-extensions i2 are forwardly and downwardly inclined slotted aper- 45 tures 45 each having a series of rack-teeth ie formed upon its upper side. A bolt 4? extends through each said aperture having next adjacent the head 48 thereof bearing upon the outer face of said extension a circular series of integral 5o gear-teeth 50 in mesh with said rack-teeth, as seen in Figs. 5 and 6 or the same may consist of a gear rigidly mounted on said bolt. The bolt 41 extends through ears 5| upon opposite ends of a transverse ledger-blade supporting-bar 52 55 to which the ledger-blade 53 is rigidly secured at 55 and projects forwardly in an edge 56 with which the blades 38 engage in shearing contact. The bar 52 is secured to said bolts by nuts 51 and is maintained in the desired pivotal relation thereto by spaced screws 58 and 59 screwthreaded in a rib 60 integral with each said extension and impinging upon ledges 6| and 62 upon opposite sides of the respective bolt in a well understood manner. Thus the ledger-bar may be bodily moved longitudinally of the apertures 45 by the rotation of the bolts 41 whose teeth 50 actuate the bar by their engagement with the rack-teeth 46, and the inclination of the bar and the ledger-blade may be adjusted through the agency of the screws 58 and 59.

63 indicates a roller rotatably mounted in brackets 65 adjustable vertically in slots 66 formed at the rear of the extensions l2 and secured at desired heights by screw-bolts 57, and thus provides a still further means of adjustment by raising or lowering the angle of the extensions about the wheel-axles l6 and raising or lowering the ledger-blade and to a lesser extent the cutter-blades 38 in their relation to the ground.

The operation of the machine generally is similar to the usual lawn mower. I have provided, however, means for adjusting the operative cutting elements of the machine which are novel and distinctive and provides a more advantageous cutting instrument for the even trimming of lawns than has hitherto been available. It is evident that the more nearly the grass is cut in a vertical line extended through the shaft 33 of the machine the better and more easily will such cutting operations be performed and the smoother will the trimmed lawn appear in its finished state or after being cut over but once. Under such conditions the uncut grass will extend substantially straight upward when engaged by the ledger-blade and the succession of cutting strokes dealt by the spiral blades 38 will cut the grass to a smooth even surface without perceptible ridges. The further to the rear of said shaft the cutting operations are performed the more uneven the grass will be cut on account of the bending over of the grass when caught by the sweep of the blades so that more or less pronounced ridges are likely to be formed. It will thus be seen that with the adjustments provided for the entire revolving cutter-frame, largely in vertical directions, and with the substantially horizontal adjustments aiforded by the novel mounting of the ledger-bar, that practically any desired relative position of the cutting devices may be provided for and that the grass may be trimmed to any desirable height from almost contact with the ground or slightly above the grass-roots to a considerable height of turf. Having described my invention, what I claim, 1s:

1. A lawn mower comprising a pair of oppositely disposed side-plates, said plates being each formed with a slot, a block adjustably mounted in each said slot and provided with a shaftbearing, means for securing said blocks in adjusted positions in said slots, a rotatable shaft mounted in said bearings, and a cutting-reel secured to said shaft.

2. A lawn mower comprising a pair of oppositely disposed side-plates, said plates being each formed with an arcuate slot, a block adjustably mounted in each said slot and provided with a shaft-bearing, means for securing said blocks in adjusted positions in said slots, a shaft rotatably mounted in said bearings, and a cuttingreel secured to said shaft.

3. A lawn mower comprising a pair of oppositely disposed circular side-plates, said plates being each formed with an arcuate slot concentric with the side-plates and included substantially within a segment of each said plate to the rear of the center thereof and below a horizontal line extending through said center, a block adjustably mounted in each said slot and provided with a shaft-bearing, means for securing said blocks in adjusted positions in said slots, a shaft rotatably mounted in said bearings, and a cutting-reel secured to said shaft.

4. In a lawn mower, a pair of oppositely disposed side-plates each having a rearward extension, said extensions being longitudinally apertured, rack-teeth upon one side of each said aperture, a bolt extending through each said aperture, a gear rigidly connected to said bolt and in meshed engagement with said rack-teeth, and a ledger-bar through which said bolts extend and adjustable longitudinally of said aperture through said meshed engagement of said gear in said rack.

5. In a lawn mower, a pair of oppositely disposed side-plates each having a rearward extension, said extensions being longitudinally apertured, rack-teeth upon one side of each said aperture, a bolt extending through each said aperture, a gear rigidly connected to said bolt in meshed engagement with said rack-teeth, a ledger-bar through which said bolts extend and adjustable longitudinally of said aperture through said meshed engagement of said gear in said rack, and means to tiltably adjust said ledger-bar.

6. A lawn mower, comprising a pair of opposite side-plates each formed with a corresponding slot, a block adjustably mounted in each said slot provided with shaft bearings, a shaft rotatably mounted in said bearings, a cutting-reel secured to said shaft, and a pair of oppositely disposed screws threaded in each said plate and engaging the respective blocks upon opposite sides for securing said blocks in adjusted positions in said slots and regulating the cutting elevation of the cutting-reel.

GROVER C. WILLFORD.

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