US1980865A - Hedge trimmer - Google Patents

Description

Nov. 13, 1934. R. 'r. KAUFFMAN HEDGE TRIMMER Filed Sept. 11, 1933 2 Sheets-Sheet l R. T. KAUFFMAN HEDGE TRIMMER Filed Sept. 11, 1933 2 Sheets-Sheet 2 Patented Nov. 13, 1934 UNITED STATES PATENT OFFICE 1 Claim.

This invention has for its object the provision of a hedge trimmer of simple and compact form which may be easily handled and in which the cutter will be driven by a motor mounted upon the frame so that the manual effort required will be minimized. The stated object and other objects which will appear incidentally during the course of the following description are attained in such a device as is illustrated in the accompanying drawings, and the invention resides in certain novel features which will be particularly defined in the appended claim.

In the drawings, Figure 1 is a side elevation of a hedge trimmer embodying the present invention.

Figure 2 is a longitudinal section with the motor in elevation,

Figure 3 is a plan view with the cover removed. In carrying out the present invention, there 2() is provided a frame or housing consisting of a lower member 1 and a cover 2, the lower member having a flat base so that it may rest horizontally upon the top of a hedge or be held perpendicularly against the side of the hedge, and being 5 further provided with an opening 3 which re ceives the lower portion of an electric motor 4 which may be of any known form and is illustrated in a conventional manner. The cover 2 is secured removably upon the base member 1 and abuts the forward end of the motor, while a supplemental cover 5 is provided and secured upon a semi-cylindrical extension 6, at the rear end of the base, the cover 5 being also semi-cylindrical so that when it is in place upon the extension 6 a tubular handle will be produced through which an electric cable '7 may be carried to supply current to the motor. The cable 7 may be of any desired length but should be quite long so that the plug 8 at the free end of the cable may be engaged in a socket in a convenient location upon an adjacent building. It may be further noted that the screw 9 which holds the cover 5 upon the tubular extension 6 may be passed between the strands of the cable '7 so that the cable may be prevented from pulling out from the motor. It may also be noted that a passage 10 is preferably provided in the base member 1 at the forward end of the handle extension through which the cable passes to reach and be properly secured to the motor.

The base member 1 of the frame or casing is provided with a circular chamber 11 in its upper side and from the walls of this chamber divergent arms 12 extend forwardly, the forward ends of saidarms being rabbeted and having a stationary knife 13 secured in the rabbets, as clearly shown in Figure v2. Intermediate lesser arms 14 also diverge forwardly from the front wall of the chamber 11 and these arms are connected by a web 15 on their undersides, said web projecting under the stationary knife 13 at the center of the same. The arms 12 are also constructed at their extremities with overhanging heads 16 which are disposed above the movable cutter 17 which rests upon the stationary cutter. The 5 movable cutter is constructed adjacent its ends with slots 18 running parallel to its rear edge, and through said slots bolts or rivets 19 pass to keep the cutter in a rectilinear path while it is operating and also to limit its movements. The bolts or rivets 19 are engaged in the heads 16 and the rabbeted terminals 20 of the several arms so that the movable cutter will be held in place and maintained in proper operative position. At its center, the movable cutter is formed with a socket 21 in its rear edge and a keeper block 22 is secured upon the cutter over said socket, said keeper being recessed in its underside, as shown at 23, to accommodate the front end of a lever or rocking arm 24 whereby motion is imparted to 0. the cutter. The lever 24 is fulcrumed upon a pin 25 which is engaged in sockets provided therefor in the upper side of the base 1 and underside of the cover 2, as clearly shown in Figure 2, and the rear end of the lever is constructed with a 5 longitudinal slot 26 which is engaged by a wrist pin 27 on the upper side of a driving gear wheel 28 which is disposed within the chamber 11 of the base. The gear wheel 28 meshes with a pinion 29 carried by a vertically disposed shaft 30 having its lower end journaled in the base at the rear of the chamber 11 and its upper end journaled in a boss 31 provided on the underside of the cover 2, it being noted that the gear 28 is provided centrally with a trunnion 32 which seats in a socket provided therefor in the base. The shaft 30 carries a beveled gear 33 which is housed within the cover, as clearly shown in Figure 2, and meshes with a beveled pinion 34 on the front end of the motor shaft 35.

The construction and arrangement of the several parts of the apparatus having been thus made known, it is thought the operation and advantages of the device will be readily understood and appreciated. The device is placed in position upon 5 the top or at the side of the hedge and the plug 8 is engaged in a socket so that current will be supplied from the house electric system, and it may be noted at this point that if desired, a switch may be inserted in the cable at the motor so that the operator may control the current without being under the necessity of returning to the house and withdrawing the plug. Such a switch has not been illustrated in the drawings inasmuch as it forms no part of my invention and may be of any well known form. The machine having been placed in position and the current supplied to the motor, the motor shaft will be caused to rotate and the rotation of the shaft will be transmitted through the pinion 34 and gear 32 to the shaft 30 which in turn will transmit the motion to the gear wheel 28 through the pinion 29. The wrist pin 27 is, of course, eccentric-to the gear wheel and as the gear wheel rotates the wrist pin will, consequently, move along the slot 26 and cause oscillation of the lever 24, the oscillation of the lever through the engagement of its front end with the socket on the movable cutter being translated into reciprocation of the cutter so that the projecting stems of the hedge will be quickly and easily severed as the machine is pushed along the hedge. It may be noted that the stroke of the cutter will be comparatively short but will be very rapid so that the desired cutting operation will be quickly and easily performed, the twigs and stems being guided and held by the lower stationary knives and quickly severed as the reciprocating knives strike against them. While I have shown and described the covers 2 and 5 as separate elements, it will be understood that they may be formed integral and suitablyshaped to fit around or over the motor and the cover will extend over the operating mechanism which will be housed between the same and the base member of the frame so that it will be thoroughly protected and the severed ends of twigs and stems cannot find their way into the operating mechanism to clog the action of the same and possibly break some of the engaging parts. The cover and base member together form a housing which may be filled with lubricant so that the moving parts will be thoroughly lubricated and will operate easily at all times, the grease working forward from the driving gears along the lever to the cutter. The device is very compact and may be very easily manipulated. The cutter is driven entirely by the power of the electric motor so thatthe only labor required of the operator is to guide themachine and hold it in proper position against the hedge.

Having thus described the invention, I claim:

A-hedge trimmer comprising a frame having forwardly diverging arms and provided in its upper side between the rear ends of said arms with a chamber, there being an opening at the rear of said chamber extending through the entire height of the frame, a cover over said chamber extending to the front end of the frame and provided in its underside with a chamber registering with the with a longitudinal slot, a gear Wheel in the chamher in the frame under the rear end of the lever, an

eccentric wrist pin on said gear wheel engaging the longitudinal slot in the lever, an electric motor mounted upon the frame with its shaft extending longitudinally of the frame and journaled between the cover and the frame, the front end of the motor abutting the cover and its lower portion projecting into the opening extending through the frame, a vertical shaft having its ends journaled in the cover and the frame respectively, gearing connecting said vertical shaft with the motor shaft, and a pinion upon said vertical shaft meshing with the gear in the chamber in the frame.

ROBERT T. KAUFFMAN. [L. s.]

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