US2021736A

US2021736A - Pruning device

Info

Publication number: US2021736A
Application number: US756762A
Authority: US
Inventors: May Friedrich
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-08-30
Filing date: 1934-12-10
Publication date: 1935-11-19
Anticipated expiration: 1952-11-19

Description

Nov. 19, 1935. F. MAY I 2,021,736

PRUNING DEVICE Filed Dec. 10, 1954 Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE Application December 10, 1934, Serial No. 756,762 In Germany August 30, 1933 4 Claims.

This invention relates to a device for pruning branches by means of knives connected with one another and operated by the intermediary of levers subjected in one direction to the action 5 of springs by means of which they are moved back, together with the knives, into their position of rest. My present improved pruning device is distinguished from the known devices for the purpose in view by the characterizing fea- 10 tures that one of the two flat knives, or knife blades respectively, forming parts of the implement and being shiftable relatively to one another is coupled with a one-armed lever, whereas the other blade is coupled with a double-armed 15 lever, preferably in such a manner that the blades can be adjusted at said levers.

Designing the pruning device in this manner renders it possible to manufacture it on the whole-sale scale at a low price, and further ad- 20 vantages are that this improved device is very reliable in service and operates unobjectionably and without jamming even if the blades are not held exactly at right angles with respect to the branches to be lopped-off.

25 In a preferred constructional form of this device the two levers mentioned are connected with one another by a serrated bar, or a saw blade respectively, may be in connection with a springactuated member able to take up the recoils.

30 The invention is illustrated diagrammatically and by way of example on the accompanying drawing which shows a side-view of a pruning device designed according to this invention.

On the drawing, I and 2 are the two knife blades which are arranged above one another and of which I is shiftable between

guide members

3 and 4 forming parts of a rigid frame 5, whereas the blade 2 is shiftable between said guide member and a guide member 1 having a guide 40 groove 6 and being preferably detachably attached to said frame 5. The blade 1 is coupled with a one-armed lever l2 fulcrumed at H to the guide member 3. In said lever is a slot l and in said blade is a slot 8, and a bolt 9 though 45 both slots can be adjusted in the slot 8 and secured therein after the adjustment. The bolt slides in the slot E3 when the lever I2 is moved up and down in order to actuate the blade I. Likewise the blade 2 is coupled with a double-armed lever ll fulcrumed at iii to the frame 5; it has a slot l3 and said lever has a slot l5, and a bolt l4 extends through both these slots. The bolt I4 can be adjusted and fixed in its adjusted position in the same manner as the bolt 9 which will be clear without a more detailed explanation.

The two blades can be moved simultaneously, counter to one another, by means of a rope 20 or the like. In the preferred constructional form shown by way of example, the rope 20 terminates already at the lever I1 and the connection between this lever and the lever I2 is effected by means of a saw-blade l8 so'that the implement can be used also for sawing purposes.

Drawing the levers back into their position of rest can be effected, for instance, either by means 5 of a helical tensile spring 2| engaging the lever l2 or by means of a helical tensile spring 22 engaging the lever l! or by both these springs, as in the drawing. It is suited to the sawing purpose to insert between the blade l8 and the lever 12 a rec-oil device H), as in the figure shown.

23 and 24 are abutment members for the two levers, and 2'1 is a wooden rod, to the upper end of which the implement is attached. The lower portion of this latter is tubular, as at 26, and receives in it the correspondingly shaped upper end of said rod. Below the guide member I the frame 5 is provided with a hook 25 serving for tearing down branches that have not been completely severed off by the knife blades.

I claim:

1. A branch pruning device, comprising, in combination, two oppositely located knife blades movable in opposite directions, means guiding said blades, a one-armed lever coupled with one of the blades and a double-armed lever coupled with the other blade, means for moving said levers with the blades back into their original position, and means for operating the said levers and the said blades.

2. A branch pruning device, comprising, in combination, two oppositely located knife blades movable in opposite directions and subjected to the action of springs adapted to move them into their original position, means guiding said blades, a one-armed lever coupled with one of said blades and a double-armed lever coupled with the other blade, and means for actuating said levers together with the said blades.

3. A branch pruning device, comprising, in com- 4O bination, two knife blades arranged oppositely to one another, guide members for said blades, 2. onearmed lever coupled with one of said blades and a double-armed lever coupled with the other blade,

a saw-blade connecting the two levers with one another at their free ends, a pulling member attached to one of said levers; and means adapted to counter-act said pulling member.

4. A branch pruning device, comprising, in combination, a frame having pairs of guides located one above the other, knife blades shiftable in said guides in opposite directions, a one-armed lever fulcrumed in said frame and coupled with one of said blades, a double-armed lever likewise fulcrumed in said frame and coupled with the other blade, springs adapted to move said levers back into their initial position, and means for operating the said levers with the blades from below.

FRIEDRICH MAY.