US2005862A

US2005862A - Hedge trimming device

Info

Publication number: US2005862A
Application number: US670078A
Authority: US
Inventors: Richard C Johnsen
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-05-09
Filing date: 1933-05-09
Publication date: 1935-06-25
Anticipated expiration: 1952-06-25

Description

J1me 1935- R. c. JOHNSEN HEDGE TRIMMING DEVICE Filed May 9, 1933 h rk INVENTOR Richard Cic/ohnsen ATTORNEY Patented June 25, 1935 UNITED, STATES PATENT OFFICE I e I 2,005,862 p HEDGE TRIMMI'NG' DEVICE 1 Richard CJJohnsen, Hillside, N. J. 7

Application May 9, 1933, Serial No. 670,078

8 Claims.

. This invention relates to hedge trimmers and particularly to electrically operated machines of this character. I

An object of the inventionis to provide an improved device which is lightin weight, easily manipulated and can be manufactured at low cost.

A further object is'to provide a device in which the drive is positive and properly balanced.

Other objects and advantages of the invention will appear from the following specification, reference being had to the accompanying drawing, in which like numerals denote like parts throughout.

Figure 1 is a view partly in section showing the front elevation of a device embodying the invention;

Figure 2 is a side elevation of the device in Figure 1, having a portion of the casing cut away; I

Figure 3 is a view showing details of the drive mechanism of the device in Figure 1;

Figure 4 is a view on line A-A of Figure 3;

Figure 5 is a view on line B--B of Figure 2;

Figure 6 is an enlarged view of the cutter blade tensioning means.

In the embodiment illustrated, there is a main plate I0 and a cover plate H which are suitably shaped to form a support and casing for the operating mechanism. Main plate In and cover plate II have integral extended portions l2 and 13, respectively, having toothed formations I4 in one edge thereof. Extending portions I2 and I3 are so shaped that when brought together and secured by bolts or rivets 15 they form a channel in which cutter or knife frame I6 is operably mounted and a slot 36 in which the cutter blade H is placed.

A power unit or motor I8 is mounted on main plate I0 and is provided with a shaft i9 extending into housing 20. A worm gear 2M is fixedly mounted on shaft 19 and is in mesh with gear 2|, which in turn is fixedly mounted on shaft 22, rotatably disposed in housing 20.

On the opposite end of the shaft 22 is fixedly mounted eccentrically, two discs 23 and 230. which are in operable connection-with connecting

rods

24 and 25. Connecting rod 25 is pivoted by screw 26 to the rear end of cutter frame I6 and connecting rod 24 is pivoted to lever 21, at 28. Lever 21 is loosely journaled to link 29 by pin 30, link 28 being journaled to main plate Ill by screw 3|. 7

The lever 21 has made integral therewith a gear segment 3| which is in mesh with the teeth thereof being of suitable form asshown alt-'33,

though any other suitable form may be'used.

Cutting knife I I being made of thin material has bothof its ends bent in the form of'ahook as shown at 34 and 35. v

A slot '31 is provided in the rear end "of {frame l6 which slot is engaged by hook 34 of knife' l 'li At the opposite end of the frame is provided a tensioning means for knife l6 oonsistingof piece 38 having a slot 39 engaging hookand an extended portion 40, which passes loosely through theupturned end of frame I6. Extended portion 40 has a slot 4i in its outerend .to receive cam '42 which is held in position and 'ro-' tateson pin 43.

The handle 44 is provided with a passageway through which passes electrical conductors 45 for conveying current to motor [8. A switch 46 is provided in handle 40 whereby lthe'current may be turned on and off as desired. A handle '41 is fixedly mounted on casing l0 for the proper handling of the device.

From the foregoing description of the details of the device its operation is easily understood.

In operation conductors 45 are connected to some suitable source of electrical energy, the operator grasps handles 44 and", depresses switch'46 energizing motor I8, and causes it to rotate and in turn rotate worm 20a, gear 2 I, shaft 22 and eccentric disc 23, which through connecting rod 24 is operably connected to knifeframe I6, causing it to reciprocate.

To balance the moving parts of the mechanism, eccentric 23a is in operable connection through connecting rod 24', lever 21, gear segment 3| and rack 32 with knife frame It, thus tending to maintain a balanced relation of the various moving parts. It is well understood that the device would be operable without the use of a second connecting rod and its associated parts, but by using these parts a smooth running and well balanced mechanism is obtained.

To compensate for the variable speeds of travel of connecting

rods

24 and 25 during their cycle of operation, lever 21 is mounted on a movable fulcrum provided by link 29, which is free to: swing within the limits fixed by pins 41a and 48. Knife frame It carrying with it knife I! now being reciprocated rapidly in relation to the stationary toothed members between which it is placed, the hedge vegetation which may be in the space beits reverse position, as shown by dotted lines.

This releases the tension on the knife and it can be easily removed. To replace the knife, the reverse procedure is employed.

It may be desired to operate the device by other power means, such as a gas engine in which case the motor may be dispensed with and the mechanism driven by a flexible shaft connected directly to the engine.

While a preferred form of the invention has been illustrated and described, many changes can be made in the construction and. arrangement of 1 parts without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. A hedge trimming device comprising a casing, saidcasing having integral extended portions forming a channel and tooth formations, said tooth formations being spaced apart, a knife frame within said channel supporting a flexible knife between said tooth formations, and means including, a motor and a pair of lever rods connected thereto, one of said rods being ,pivotally connected to said knife, the other of said rods being linked to said casing.

2. A hedge trimming device comprising a casing, said casing having extended portions forming a channel and tooth formations, said tooth formations having serrated edges, aknife adjacent said tooth formations, and means including a motor and a pair of lever rods connected thereto, one of said rods being pivotally connected to said knife, the other of said rods being linked to said casing.

3. In a hedge trimming device, a casing having extended portions forming a channel, a knife framemounted in said channel, an eccentrically mounted rotatable disc within said casing, a connectingrod in operable relation with said disc and said knife frame, a second eccentrically mounted rotatable disc, and a second connecting rod in operable relation with said second disc and through a lever and geari segments with said knife frame, said lever being mounted on a movable fulcrum secured to said casing.

4. A hedge trimming device having a casing, a knife'frame supported by said casing, a'flexible knife mounted on said frame, means on said frame for holding said knife under fixed tension and means including a motor and a pair of lever rods connected thereto, one of said rods being pivotally connected to said knife, the other of said rods being linked to said casing.

5. A hedge trimming device, comprising an upper and a lower plate forming a casing, said plates having integral elongated portions forming a channel, said channel adapted to support a knife frame, a knife frame in said channel, a flexible knife supported under tension on said frame, and means mounted on said casing and means including a motor and a pair of lever rods connected thereto, one of said rods being pivotally connected to said knife, the other of said rods being linked to said casing.

6. In a hedge trimming device a casing, having extended portions forming a channel, a knife frame mounted in said channel, an eccentrically mountedrotatable disc'within said casing, a connectingrod in operable relation with said disc and knife frame, a second eocentrically mounted rotatable disc, and a'second connecting rod in operable relation tosaid second disc and through a lever and gear segments with said knife frame, said lever being mounted upon a fulcrum secured tosaid casing, said eccentrics being mounted to operate apart to actuate said connecting rods whereby said knife'is caused to reciprocate by the alternate action of said rods.

7. A hedge-trimming device comprising a casing, a knife adapted to reciprocate therein, and motor means for reciprocating said knife carried by said casing including a pair of levers one of said levers being connected to said motor means and pivoted on said knife, the other of said levers being connected to said motor means and to a link movably supported on said casing, whereby said knife may be reciprocated while said levers are in substantially balanced relation.

8. In a hedge trimming device, a casing having portions forming an extended channeled arm, a

RICHARD C. JOHNSEN.