US3360859A - Pruning cutter - Google Patents

Description

2, 1968 L. K WATSON 3,

I PRUNING CUTTER Filed Dec. 30, 1965" 2 Sheets-Sheet 1 INVENTOR ZEJTER K. M44750 Jan. 2, 1968 L. K. WATSCN 3,360,859

PRUNING CUTTER Filed Dec. 30, 1965 2 Sheets-Sheet v INVENTOR 5 7152 K. W4 TSON ATTORN United States Patent 3,360,859 PRUNING CUTTER Lester K. Watson, Shiloh, Pa., assignor to Pennsylvania Saw Corporation, York, Pa., a corporation of Pennsylvania Filed Dec. 30, 1965, Ser. No. 517,709 4 Claims. (Cl. 30-249) ABSTRACT OF THE DISCLOSURE A pruning cutter in which a blade is mounted for opera tion within a slot between opposite outer faces of a booklike extremity arranged to be mounted on the end of a pole, the blade being pivoted upon a pin extending at both ends beyond the outer faces of said hook-like extremity and a spring which is bent relatively sharply upon itself to form two nearly parallel legs has similar coils formed in said legs which are received respectively upon said ends of said pivot pin for positioning thereon and the extremities of said legs are received beneath projecting positioning ears on said outer faces of said hook-like extremity and the bight of said opposite end of said spring receives one edge of an operating arm projecting from said blade in a manner to constantly urge the blade to retracted inoperative position.

This invention pertains to a pruning cutter and, more particularly, to a pruning cutter of the type intended to be supported upon the end of a relatively long handle or pole and being capable of pruning the branches of trees, bushes and the like, at substantial distances from where the operator is supporting the handle or pole.

Pruning cutters and shears of the type referred to, and particularly those adapted for remote operation at substantial distances above or laterally outward from the operator have been available for substantial periods of time. It is not infrequent however in the operation of pruning cutters of this type that pieces of twigs or branches will become wedged between the cutting or shearing blades, this being of such extent that sometimes movement of the cutting blade to inoperative position is prevented by the means normally provided for such movement.

Various attempts also have been made heretofore to provide effective spring and other types of power means to cause movement of the shearing or cutting blade to inoperative position in pruning cutters of the type referred to but, in general, such arrangements have either been ineffective or are of substantial complexity so as to add materially to the cost of manufacture of the pruning cutter or require substantial forces to operate the same against the action of such movement-inducing spring means.

Part of the difficulties experienced in the use of pruning cutters of the type referred to, especially at remote distances from the operator, have arisen from the fact that a true shearing type of cutter has been employed, such as in scissors, whereby slivers or other parts of trees or bushes can become wedged between the relatively movable blades and substantially lock the same against ready opening or closing movement of the movable blade with respect to the stationary blade with which it coacts.

It is the principal object of the present invention to obviate the foregoing difficulties of existing pruning cutters by providing a pruning cutter in which a cutting blade, as distinguished from a shearing blade, is operated within a slot between the opposite surfaces of a hook-like extremity upon a supporting member, and pivot means are provided to connect the blade with respect to the supporting member in such manner that a relatively long actuating arm is provided, whereby spring retracting means of improved and highly efiicient design are capable of engaging the actuating arm of the cutting blade at such position that return of the blade to its inoperative position following a cutting operation thereof is assured under substantially all operating conditions.

Another object of the invention is to construct a pivot means and a retracting spring in such manner that it may be readily assembled with the pivotally connected supporting member and cutting blade without requiring any tools and, further, the mere connection of the spring means with the supporting member and blade actuating arm serve to retain the spring in operative position.

A further object of the invention ancillary to the foregoing comprises projecting the pivot means in opposite directions from opposed faces of the operating member and forming the spring with a bight intermediately of the ends thereof which engages one edge of the actuating arm of the cutter member, the legs of the spring each being provided with coiled portions receiving the projecting ends of the pivot means to position said legs relative to the axis of the pivot means, and the free ends of the legs of said spring means being engaged by addition-a1 anchoring means formed on the supporting member and preferably provided with seats within which said ends are received to retain said ends operatively in fixed relationship with respect to the supporting member.

Still another object of the invention related to the preceding object comprises so shaping the bight portion of the spring with respect to the coiled portions of the legs thereof that said bight portion engages the actuating arm at least substantially midway between the axis of the pivot and the outer end of said arm.

A still further object of the invention is to provide a preferably anti-friction sheave on the outer end of the actuating arm and an elongated flexible member is connected to the supporting member adjacent the end thereof opposite the hooked end, said flexible member extending around said sheave in such manner that when the outer end thereof is pulled, substantially less force is required to operate the cutter than if the actuating lanyard, or the like, were connected directly to the outer end of the actuating arm.

Details of the foregoing objects and of the invention, as well as other objects thereof, are set forth in the following specification and illustrated in the accompanying drawings comprising a part thereof.

In the drawings:

FIG. 1 is a side elevation illustrating a pruning cutter embodying the principles of the invention connected to one end of a foreshortened elongated supporting handle or pole, the cutting blade being shown in retracted, inoperative position in this figure.

FIG. 2 is a similar view of the pruning cutter per se shown in FIG. 1 but illustrated on a substantially larger scale, the cutter being shown connected to a short, fragmentary portion of a supporting handle or pole.

FIG. 3 is a longitudinally sectioned view of the supporting member of the pruning cutter illustrated in FIG. 2, the same being shown in relation to a fragmentary portion of a handle and a fragmentary portion of a cutting blade illustrated in phantom.

FIG. 4 is a fragmentary view of the pruning cutter shown in FIG. 2, as seen from one edge thereof, part of the supporting member of the cutter assembly being illustrated in longitudinal section to disclose details of its connection with a handle or pole, this view showing to advantage the shape of the spring which returns the blade to inoperative position.

FIG. 5 is a view similar to FIG. 3 but illustrating the cutter and actuating arm thereof in full line and shown at the end of a cutting stroke with respect to the sup- 3 porting member and its U-shaped holding member at one end thereof, the latter being illustrated in phantom.

FIG. 6 is a top plan view of the supporting member and the U-shaped holding member thereof as seen on the line 6--6 of FIG. 3.

FIG. 7 is a face view of the spring by which the blade is returned to inoperative position, said spring being illustrated in operative position with respect to the pivot means and a fragmentarily illustrated portion of the supporting member for the blade, the latter being shown in phantom.

, FIG. 8 is a fragmentary side elevation showing anchoring means for the free ends of the legs of the spring means to fix the same wtih respect to the supporting member of the pruning cutter assembly.

FIG. 9 is a fragmentary edge view as seen on the line 99 of FIG. 8 and showing, in phantom, the free ends of the spring legs positioned within the seats formed therefor within said anchoring means.

FIG. 10 is a face view of the preferred form of pivot means for rotatably connecting the blade to a supporting member. 7

FIG. 11 is a fragmentary view of the cutting end of the blade to illustrate the relationship of the contour of the cutting edge with respect to the pivot hole formed in the blade.

FIG. 12 is a fragmenary sectional view of the blade as seen on the line 1212 of FIG. 11.

FIG. 13 is a face view of the preferred anti-friction sheave pivotally connected to the outer end of the actuating arm of the cutter member.

Referring to the figures, in which similar reference numerals refer to similar parts, the pruning cutter embodying the principles of the present invention comprises a supporting member 10 which preferably is provided at one end with a socket 12 arranged to receive one end of a handle or pole 14. In accordance with the principles of the invention, the pruning cutter to which the present invention pertains is of the type which may be operated at a substantial distance from where the operator is located, depending upon the length of the pole 14 for example.

The opposite end of the supporting member 10 comprises a hooked or substantially U-shaped holding member 16 which, for the major extent thereof is provided with a slot 18, thereby dividing the holding member 16 longitudinally to form opposite side members 20. As seen to best advantage from FIG. 3, the slot 18 extends from the tip of the holding member 16 to the inner end of the socket member 12, there being a connecting portion 22 at the tip end. Also, intermediately of the ends of the slot 18 is a transverse stop member 24 integral with and extending between the opposite side members 28 of the holding member 16. The stop member 24 is best shown in FIG. 3. Preferably, the supporting member 18, including all portions thereof thus far described, may be formed economically from suitable metal, by a molding operation, thereby minimizing the cost of production thereof.

Mounted for operation within the slot 18 is a cutting blade 26 which is preferably formed from suitable steel and may be stamped from appropriate sheet stock to provide at one end a preferably curved and sharpened end portion 28 and an actuating arm 38 which projects oppositely from the sharpened end portion 28 wtih respect to the pivot hole or bearing 32 of the blade member. A pivot hole or bearing 34 is formed in each of the opposite side members of holding member 16, coaxially with respect to each other for the reception of a pivot member 36 therethrough, the opposite ends of said member preferably projecting beyond the opposite faces of the holding member 16, as is evident particularly from FIGS. 4 and 7.

As shown in FIG. 10, the pivot member 36 may be formed as a tubular sleeve having a longitudinal slot 38 therein to permit limited compressability and expansion of the pivot member, particularly since the opposite ends thereof preferably are beveled, as clearly shown in FIG. 10. The provision of the slot 38 permits limited compressability of the member into the axially aligned pivot hole 34 in holding member 16, thereby eliminating any need for means to prevent relative axial movement between the pivot holes 34 and pivot member 36 when press-fitted into operative position therein. However, if desired, the pivot member 36 may be of solid bar stock and also preferably press-fitted into the pivot holes 34.

Referring particularly to FIGS. 11 and 12, it will be seen that the sharpened cutting end portion 28 is curved with an increasing radius with respect to the axis of the pivot hole and bearings 32 of blade member 26. To a certain extent, the shape of the sharpened end portion 28 may be regarded somewhat as a segment of a spiral. Further, it is preferred that the sharpened end portion 28 be beveled from opposite sides as best viewed in FIG. 12, whereby a distinct severing cut, as distinguished from a shearing cut, is afforded by the cutting blade 26 relative to a branch or twig contained within the hook opening 40, wherein the branch or twig is securely held while the cutting edge 28 progressively moves in an incisive manner through the entire diameter of the twig or branch as the cutting blade 26 is moved from the fully inoperative position illustrated in FIG. 3, in phantom, to the fully operative position, as shown in FIG. 5. Due to the shape of the sharpened edge 28 of the cutting end of blade 26, there is substantially no possibility of slivers or portions of twigs or branches becoming wedged between the cutting blade and the inner surfaces of the opposite side members 20 of the holding member 16 which define the slot 18 in which the sharpened end portion 28 of the blade operates.

One of the primary advantages of the present invention resides in the biasing type return spring 42 which is provided for purposes of effecting retreating movement of the cutting blade 26 from the fullest extent of cutting position, as shown in FIG. 5, to the fully retracted, inoperative position shown in FIGS. 1-3, for example. The return spring 42 not only serves to move the cutting blade 26 in retracting direction but, of equal importance is the fact that the particular shape of the blade, especially as exemplified by the views in FIGS. 4 and 7, serves to measurably assist in retaining the spring in operative position without the aid of auxiliary or additional elements or components, in view of the following characteristics thereof.

Referring especially to FIGS. 4 and 7, it will be seen that the spring 42 is provided intermediately of the ends thereof with a bight portion 44, it being understood that the spring 42 preferably is formed from conventional spring wire of suitable diameter and strength. The bight portion 44 is formed by bending the spring relatively sharply upon itself and the opposite legs of the spring extending from said bight portion are provided intermediately of the ends thereof with coiled portions 46 which are shown to good advantage in FIGS. 2, 4, 7 and 8. Preferably, the diameter of the coiled portions is slightly greater than that of the projecting ends of the pivot member 36, as is evident especially from FIG. 8.

The engagement of the bight portion 44 of the spring 42 with one edge of the actuating arm 30 preferably occurs at least substantially midway between the axis of the pivot member 36 and the outer end of the actuating arm 30, thereby providing highly ample mechanical advantage with respect to generating force adequate to cause retracting movement of the cutting blade 26 from its position at the completion of a cutting operation, such as shown in FIG. 5, to its fully retracted position shown in FIGS. 13. To cause the spring 42 to function in this manner, the free ends 48 of the opposite legs of spring 42 are fixed with respect to holding member 16 by means of anchoring abutments 50 which preferably are cast integrally with the holding member 16 so as to project from the opposite outer surfaces thereof. Also, the abutments 50 each preferably have a recess 52, shown to advantage in FIG. 9, which are complementary to the free ends 48 of spring 42, the depth of the recesses being adequate to readily retain said free ends of the legs of the spring therein. Further, the angularity of the free ends 48 of the legs of the spring with respect to the other portions of said legs which terminate in the bight portions 48, is such that when the coils 46 in the legs of the spring are each disposed around projecting ends of the pivot member 36, the bight portion 48 engages the adjacent edge of the actuating arm 30 as shown in FIG. 2, for example, and the free ends 48 of the legs of the spring are disposed in the recesses 52 of anchoring means 50, the cutting blade 26 will be disposed by the force of the spring within the fully retracted or inoperative position thereof such as shown in FIGS. 1-3. This position further is controlled by engagement of one edge of the cutting blade 26 with the stop member 24 shown in FIG. 3.

As a result of the foregoing, not only does the angularity between the free ends 48 of the spring with respect to the bight portion 44 thereof, but also the tension induced by the coiled portions 46 thereof, serve to maintain the spring in operative position but preferably, the tension is not so great that the spring may not be mounted in operative position simply by placing it in straddling relationship with respect to the actuating arm 30, disposing the coiled portions 46 over the projecting ends of pivot member 36 and snapping the free ends 48 of thelegs of the spring, manually, into the recesses 52 of the anchoring abutment 50. In addition, when the spring 42 is formed, the legs thereof extending in sharp angular relationship to each other from the bight portion 44 preferably are bent at least into the position shown in FIG. 7 and preferably even a little closer together so as to insure that the resilience of the bight portion 44 will serve to maintain the coiled portions 46 operatively upon the projecting ends of the pivot member 36 without necessarily relying upon the reception of the ends 48 of the legs of the spring within the recesses 52.

From the foregoing, it will be seen that the attachment of the spring member 42 to the pro-assembled cutting blade 26 and holding member 16 may be accomplished quickly, inexpensively, and without the aid of any tools, special or otherwise. Further, the mounting of the spring 42 in operative position results in automatically positioning the cutting blade 26 in its fully inoperative position, whereby the hook opening 40 is completely open for purposes of being placed over a branch or limb to be severed by the pruning cutter.

Further to facilitate the movement of the cutting blade 26 in operative direction, which is clockwise as viewed in FIGS. 1-3 and 5, the present invention includes the provision of a flexible elongated member 54 which, in its preferred embodiment, comprises a link-type chain similar to a bicycle chain so the invention is not to be re stricted to the use of a chain-type flexible member. One end of the flexible chain is connected, by means of an appropriate clevis 56, or the like, fixed at one end of the socket 12, and the opposite end thereof preferably terminates in an attaching ring 58. Said other end also preferably passes through an anti-friction sheave 60 which preferably is pivotally connected to the outer end of actuating arm 30 and supports an anti-friction roller 62 around which a flexible chain member 54 extends at least partially, especially when the cutting blade 26 is moved toward or to the fullest cutting position as exemplified diagrammatically in FIG. 5.

Referring to FIG. 1, the preferred operating means for the flexible member 54 is shown in that a suitable lanyard 64, such as a rope or flexible cable, is connected to the attaching ring 58 extends along the handle or pole 14 so as to be within ready reach of the operator. By pulling upon such lanyard, the flexible member 54 extends substantially 180 around the anti-friction roller 62, thereby multiplying the force applied to the lanyard 64 so as to produce substantially twice the force for operating the cutting blade 26 as compared with pulling directly upon the outer end of actuating arm 30.

Reverting to the return spring 42 and particularly its manner of engagement with the actuating arm 30 of cutting blade 26, substantially no obstruction is present to become fouled with twigs and it will be seen particularly from FIGS. 4 and 7 that the sharp angular bend comprising the bight portion 44 actually constitutes a relatively sharp, reverse bend and the opposite leg portions immediately adjacent the bight portion 44 are disposed relatively close to the opposite surfaces of the actuating arm 30 so as to prevent any lateral movement of the bight portion of the spring with respect to said actuating arm. Further, it is apparent that during movement of the actuating arm 30 about the axis of the pivot member 36, the bight portion 44 is capable of at least limited sliding movement with respect to one edge of the arm 30. Similarly, the coiled portions 46 of the legs of the spring 42, being of slightly larger diameter than the pivot member 36, are capable of limiting floating movement, transversely to the axis of the pivot member 36, thereby minimizing wear between the spring and pivot member. Of even greater importance however is the fact that when the cutting blade 26 has been moved especially to the fullest cutting position such as exemplified in FIG. 5, the spring 42 is placed under the maximum amount of tension, whereby the greatest force of the spring is applicable instantaneously to move the blade 26 to open position immediately upon manual force being released from the actuating arm 30. By virtue of the shape of the spring 42, as the cutting blade 26 and its actuating arm 30 are moved from the inoperative position such as shown in FIGS. 1-3, to the fullest stroke thereof, as limited by the inner end 66 of socket portion 12 of the supporting member 10, the tension in spring 42 is continuously increased.

While the invention has been described and illustrated in its several preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as claimed.

I claim:

1. A pruning cutter comprising a supporting member terminating at one end in a substantially U-shaped holding member arranged to receive a limb to be cut and the other end being connectable to a handle, a cutting blade having a sharpened end portion and an actuating arm extending therefrom, and a pivot member rotatably connecting said cutting blade adjacent said sharpened end thereof to said supporting member adjacent said U-shaped holding member for movement of said sharpened end of said cutting blade into severing engagement with a limb or twig when disposed within said holding member and said blade is pivotally moved in one direction by force applied against said actuating arm, in combination with a biasing spring coiled around said pivot member to position said coil exteriorly of said holding member, and said spring having one end extending radially from said coil, the outer portion of said end of said spring being fixed relative to said supporting member a limited distance from said pivot and the opposite end of said spring projecting substantially radially from said coil and the outer portion of said opposite end engaging said actuating arm of said cutting blade at an appreciable distance from said pivot and operable to move said sharpened end portion of said blade away from said U-shaped holding member when said actuating arm is released from said force, movement of said cutting blade in cutting direction by said actuating arm causing tensioning of said coiled spring, whereby it is under maximum developed tension immediately upon said actuating arm being released from said force.

2. The pruning cutter according to claim 1 in which said pivot means projects at its opposite ends beyond the opposite faces of said supporting member; said spring being elongated and bent upon itself intermediately of the ends thereof to form a bight receiving one edge of said actuating arm and legs projecting similarly away from said bight and each having a coiled portion respectively reciving said projecting ends of said pivot means; and said supporting member also having anchoring means respectively formed on opposite faces thereof and individually receiving and retaining the free ends of said legs of said spring in operative biasing positions relative to said supporting member.

3. The prunning cutter according to claim 2 in which said sharpened end of said blade is curved on an increasing radius relative to the axis of said pivot means and said actuating arm of said blade extends oppositely from said sharpened end a substantially greater distance relative to said pivot means than said sharpened end, and said bight of said spring engaging said actuating arm at least substantially midway between said pivot means and the outer end of said arm to afiord efiicient levering action of said spring upon said arm.

4. The pruning cutter according to claim 2 further including anti-friction sheave means pivotally connected to the outer end of said actuating arm, and an elongated flexible member connected at one end to said supporting member adjacent said other end thereof and the other end of said flexible member extending movably around said sheave means, whereby when said other end of said flexible member is pulled, pivotal moment of said cutting blade is effected with increased force as compared with direct pulling upon the outer end of said actuating arm of said cutting blade.

References Cited UNITED STATES PATENTS 296,514 4/1884 Bottomley a; 30188 X 1,181,579 5/1916 Dodge et al. 30-249 1,761,469 6/1930 Donkel 30249 FOREIGN PATENTS 366,077 7/ 1906 France. 1,379,020 10/1964 France.

WILLIAM FELDMAN, Primary Examiner.

I. C. PETERS, Assistant Examiner.

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