US1454917A - Pruning shears - Google Patents

Description

May 15, 1923.

L. J. BARRETT PRUNING SHEARS Filed Sent. 11. 1922 I'mnfcrr 31/ LG w ncqs Patented May 15, 1923.

- marten 5mm I rattan LEON J. BARRETT, 0F WORCESTER, MASSACHUSETTS.

raumne SEEABS.

Application filed September 11, 1922'. Serial in). 537,514.

To all whom it may concern: v

Be it'known that I, LEON J. BARRETT, a citizen of the United States, residing at Worcester, in the countyof Worcester and State of Massachusetts, have invented a new and useful Pruning Shears, of which the following is a specification.

The principal object of this invention s. to provide a pruning shear capable of operation with sufficient multiplication of power to permit of cutting through a relatively large limb by hand.

The principal feature of the invention consists in an improved ratchet deviceand its connections for permitting of the use of the device for the purpose specified, employing a leverage of relatively large ratio.

The invention also involves improvements in the means for automatically throwing in and disconnecting the ratchet and the relative arrangements of the parts for producing an effective device for this purpose with the great leverage ratio.

Reference is to be had to the accompanying drawings, in which Fig. l is a side elevation-of a pair of'pruning shears constructed in accordance wlth this invention and shown in open position ready to start the cut; f V

Fig; 2 is an edge View of the same; and

Fig. 3 is a side view showing the device applied to a pole and operated by a flexible connection, and illustrating it in its cutting position'with the knife almost through the cut.

Referring-first to Figs. 1 and 2, I have shown the main member 10'consisting of a malleable iron casting preferably provided with a handle 11. On this casting is fixed by bolts 12 or the'like a blade 13 of tool steel and shown as having a bevel cutting edge-of arcuate form; Pivoted on a bolt 14 on this malleable iron casting is a ratchet segment 15. I have indicated in dotted lines an adjusting device for adjusting this ratchet member to take up wear. This is shownin the form'of a nut 16 having teeth in which an adjusting pawl 17 is adapted to engage, but this is not shown in detail as it does'not constitute afeature of this invention.

On this ratchet member are a series of ratchet teeth arranged concentric with respect to the bolt 1 1 and it is provided with two stops 18 and. 19 at opposite ends for enbutco-operating with the blade 13'.

swings with the ratchet segment 15 about gaging the handle 20 of a pawl'21 -which adapted to engage the ratchet teeth. As the ratchet segment moves to either extremity, one of the stops engages the han'dle ZO and is art at; new f f i throws the pawl 21 in or out as thecase may v be. The pawl is held in either position by a pin 22 on it engaging the rounded end 23 I of a spring 24 mounted on the malleable iron plate 10. This spring is located in a recess 25 in this malleable iroirplate, the wall-of which has aprojection 26 for engagingthe shank of the spring and forcing its end 23.

always into contact with the pin22 Mounted on the ratchet plate 15, whiclris preferably of malleable cast .iron, Ineans of bolts 27 is a cutting blade of tool steelf28, This the pivot 14.

Pivotally'mountedon a bolt or'fstud I on the plate 10 is a handle '31 on whichfis ratchet pawl 83 has a sprlng 34 for normally forcing it into contact with the teeth of the. v

ratchet and it also has a recess with aprojection 35 at its end for engaging a pr0]ection 29 on the pawl 21 and holding it out of ens gagement with the teeth at a certain time, as

will appear.

The operation of the deviceis asffollowsti With the parts in the position shown in Fig. 1, the handle 31 is drawn bacln The spring 34: holds the pawl 33 contact withthe tceth of the ratchet 15 and the spring 24; acts ;on'

the pin 22"to hold the pawl 21 also yieldlngly in contact with the same teeth. vAs.

the handle 31 is drawn back away from the handle 11, the pawl 33 ratchetsover the teeth and then when the handles are forced to The operator can take a I jection 29-on the pawl 21-and force that pawl 33 out of engagement with the teeth,

75 pivotally mounted on stud or bolt 32a ratchr.

pawl 33. This handle 31 co opera tes i. with the handle 11 and the pawl 33 engages the ratchet for operating the device Thismoving the pin 22 over the elbow 23 at the same time.

Obviously, the hook blade 13 being hooked over thelimb, the limb is not fully cut oil until the blade 28 moves far enough to contact with the highest point of the curve of. the hook blade. It will be understood that the cutting ordinarily commences when the blade 28 first crosses the end of the hook blade if the device is used on a limb of the maximum size. If used on a limb of smaller size, it will cut in afterthatpoint is reached. This prevents the blades crossing each other after the cut is commenced; The operator continues the vibration of the handles until the limb is entirely cut oil.

At this point, stop 18 engages handle 20 forcingpawl'21 out of contact with the teeth. The pin 22 slips over the elbow 23 of spring 2-1 and the pawl 21 is thus yieldingly held out of position. This is the position shown in. Fig; 3, which will be presently described.

Now, the shears can be opened to the position shown in Fig. 1'.

Further continued motion of arm31 and hence stop 18" forces projection 29 into engagement with projection 35 and pushes pawl out of engagement with the ratchet teeth. This allows the" ratchet 15, through the action of the spring 36, to be returned to its original position, causing stop 19 to engage handle20 and forcing pawl 21 back to its normal position in engagement with ratchet 15; The operation can'then start over again.

It will be observed that a spring 36 normally pulls the ratchet plate into a position to open the shears and constantly acts against the ratchet pawl 33.

In the form shown in Fig. 3, instead of having two handles, 1 have shown the malleable casting 10 as mounted on a pole 4:0 and in place of the" handle 11 l have shown a lever 41 operating in the same way, except that it is manipulated by a flexible connection 42 extending downwardly and alternately pulled and released to perform the cutting action in the same way as that described above. It is pulled up by a spring 43.

Although I have illustrated and described only two forms of the invention,I am aware of the fact that further modifications can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to all the details of construction herein shown and described, but what I do claim is 1. In a pruning shear, the combination of a hook blade with a rachet segment pivota'l-ly connected therewith, yielding means for moving said segment in one direction, a leverpivotally mounted with respect to said blade and having a pawl thereon for operating the ratchet against the action of said spring, a second pawl pivotally mounted nee-eel? with respect to said blade engaging said ratchet, and means for automatically moving the second pawl into or out of engagement with the ratchet at each end of the stroke of the ratchet segment.

2. In a pruning shear, the combination of a main blade, a supporting handle connected therewith, a hook-shaped blade mounted thereon, a ratchet segment pivotally mounted on said blade, a lever pivotally mounted on the blade at a distance from the point where the segment is mounted on it and beyond the segment teeth, a pawl pivoted on said lever for engaging and operating the'ratchet as the leverswings on its pivot, a second pawl mounted on the first namedblade and having an arm projecting inwardly over the surface of said segment, said segment having fixed stops near' its opposite ends for'engaging said second pawl and swinging it back' and forth into and out of engagement with the teeth of the ratchet.

3. In a pruning shear, the combination of a n'iain'blade. a supporting handle connected therewith, a hookshaped blade mounted thereon, a. ratchet segment pivot ally mounted on said blade, a lever pivotally mounted on the blade at a distance from the pointwhere the segment is mounted on it and beyond the segment teeth, a pawl pivoted on said lever for engaging and operating the ratchet as the lever swings on its pivot, a second pawl mounted on: the first named blade and having an arm projecting inwardly over the surface of said segment, said segment having fixed. stops near its opposite ends for engaging said pawl and swinging it back. and forth into and out of engagement with. the teeth of the ratchet, the last named pawl having a pin projecting therefrom, and a spring mounted on said blade having an elbow for engaging either side. of said pin to hold. the pawl either in or-out of activeposition.

4. In a pruning shear, the combinationof a main blade, a handle connected therewith, a blade mounted thereon, a ratchetsegment pivotally mounted on said blade, a lever pivotally mounted 011 the blade at a distance from the point where the: segment is mounted. on it and beyond the segment teeth, a pawl pivoted on said lever for engaging and operating the ratchet. asthe lever swings on its pivot, a second pawl mounted on the first named blade and having an arm projecting inwardly over the surface of said segment, said segment having fixed stops near its opposite endsv for engaging said pawl and swinging it back and forth into and out of engagement with the teeth of the: ratchet, the last named pawl having means for holding. it yieldingly in or out of active position.

5. In a pruning shear, .the combination tance from the point where the segment is mounted, a pawl pivoted on said lever for engaging and operating the ratchet as the lever swings on its pivot, a second pawlhaving an arm, said segment having stops near its opposite ends for engaging said second pawl and swinging it back and forth into and out of engagement with the teeth of the ratchet.

6. In a pruning shear, the combination of a fixed blade, a supporting handle con nected therewith, a second blade mounted thereon, a ratchet segment, a lever at a distance from the point where the segment is mounted, a pawl pivoted on said lever for engaging and operating the ratchet as the lever swings on its pivot, a second pawl having an arm, said segment having stops near 1ts opposite ends for engaging said second pawl and swinging it back and forth into and out of engagement with the teeth of the ratchet, said pawls having interengaging means for forcing the first pawl out of engagement with theratchet teeth when the blades come to closed position.

7. In a pruning shear, the combination f of a fixed blade, a supporting handle connected therewith, a second blade mounted thereon, a'ratchet segment, a lever at a distance from the point where the segment is mounted, a pawl pivoted on said lever for engaging and operating the ratchet as the lever'swings on its pivot, a second pawl having an'arm, said segment having stops near its opposite ends for engaging said second pawl and swinging it back and forth into and out of engagement with the teeth of the ratchet, the second pawl having means adapted to engage the first pawl, when the second pawl is forced against one of said stops and forcing the first pawl out of engagement with the ratchet teeth, and a spring constantly acting on the ratchet to open the blades and bring the other Stop into contact with said arm to release the first pawl.

In testimony whereof I have hereunto affixed my signature.

. LEON J. BARRETT.

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