USRE14614E - Pruning-shears - Google Patents

Description

E. McKENNEY.

PRUNING SHEARS APPLICATION FILEID JUNE 30. 19x1.

Beissued Mar. 18, 1919. Q 14,614.

2 SHEETS-SHEET I.

VII,-

E. McKENNEY.

PRUNING SHEARS.

APPLE/(HON FILED mm: 30. 1911.

Reissued Mar. 18, 1919'.

Inventor" U ly zi2 .Atlorney UNITED STATES PATE T orr ou.

EMERSON maxnmmy, or BANGOR, MAINE, assrenon, BY manor Aim MESNE ASSIGNMENTS, TOMcKENNEY-GARR COMPANY, A CORPORATION or MAINE.

Specification of Reissued Letters'l atent. Reiss d Ma 18 1919 :Original No. 1,178,587, dated February 29, 1916, Serial No. 52,207, filed September 23, 1915. Application for reissue Medium 30, 1917. Serial No. 178,037.

. is designed.

Another object of my invention is to provide pruning shears provided with removable cutting blades of such formation as to facilitate a deep clean cut into the branch without bruising or injuring the same.

Still another object is to provide a device of this character whose cuttin blades have stops formed thereon for limiting the movement of one toward the other so as to prevent dulling of the cutting edges of the said blades by coming in violent contact with one another.

Still a further object of my invention is to provide pruning shears whose movable cutting blade is readily removable from the rack bar of the device.

With these and other objects in view my invention resides inthe novel features of construction, combination and arrangement of arts as will be hereinafter more particular y described and claimed.

In the accompanying drawings Figure 1 represents a side elevation of a pair of pruning shears embodying mylm- .proved features of construction;

Fig. 2 is a front edge view thereof, with the cutting blades arranged in contact with one another; Fig. 3 is a verticalsection on line 33 of Fig.4; I

Fig. 4 is a central vertical longitudinal section on line H of Fig. 2;

Fig.- 5 is a similar view but showing the cutting blades spaced apart;

Figs. 6 and 7 are horizontal sectional views on the lines 66and 77 of Fig. 4; Fig. 8 is-a side elevation of the movable cutting blade and the rack arranged. in ux taposition.

Referring tothe-drawingswherein similar reference characters designate corresponding parts throughout the several views, 1 indicates broadly a housing adapted to inclose the movable cutting blade and the operating mechanism therefor.

Formed integrally with one end of this housing 1 is a tubular shank 2 adapted to be secured to the end of a suitable handle or pole 3, while from the opposite end of said houslng 1 a shank 4 projects, said shank having 1ts free end extended laterally to provide an arm 5. This arm 5 is provided on its lower edge with a groove 6 which communicates with a similar groove 7 formed. in the adjacent edge of said shank 4,. said grooves being adapted to receive the edges of a removable stationary cutting blade 8;

The groove 7 communicates with a suitable guide passage 9 formed through the housing 1 at its forward portion, said passage being adapted to receive a movable cutting blade 10. This movable cutting blade 10 is provided with a shank 11 formed on its lower edge which isadaptedto be inserted in a groove 12 formed in one edge of a rack bar 13, said rack bar having formed integrally with its lower end an ear 14 for a purpose to appear.

The rack bar 13 is preferably though not necessarily tapered. from its lower toward-its outer end, thus causing the toothed edge thereof to be inclined. The gear sector 17 adapted for coaction with the said rack bar is also of a peculiar shape from its pivot to the teeth and meshes with the rack-teeth as the sector is moved to the right about its pivot. This arrangement, including the initial position and subsequent movement of operating arm 18' as indicated in Figs. 1 and 4, has the effect of giving the device increasing leverage and-cutting power as the blades move toward each other through the limb which is being severed. The shank 11 of this cutting blade. 10 is provided with a notch 15 which is adapted to coact with a stop 16 forward in, said groove 12 When these two parts of the device. are assembled, as shown in Fig.v 5 of the drawings, with the stop 16 in the slot 15, any longitudinal movement. of ,theparts relative to, one another will be prevented.- Lateral movement" thereof is also prevented by the, gear sector 17 which coacts with the rack 13 and holds the aforesaid parts in contact with the front wall; of the guide passage 9. This gear sector 17 is formed integrally withvone end of an oper ating arm 18, while at theother end of said arm is formed an eye 19 in which a suitable operating cable 20 is adapted to be placed. The member 17 is formed with an eccentric pivot hole 21 which is adapted to aline with similar holes 22 formed in the walls of the housing 1, and receive therethrough a pivot When in normal position, the operating arm 18 is positioned as shown in pin 23.

Fig. 1, with its forward edge abutting a stop 24 formed on the edge of the housingmember 1, but when this arm, is moved downwardly toward the position in which it Will extend in a line at right angles with the line of the blade or cutting knife actuation,

' as in Fig. 4, movement, with constantlyincreasing power, will be imparted to the' 'ear and rack. to raise the movable cutting blade into the position shown in Figs. 2 and 4.

Both the stationarycuttingblade 8 and the movable blade 10 have a gradually tapering" formation from approximately the base to the cutting edge thereof and are provided along one edge with a thickened pore tion 25 and 26 respectively, which is adaptedyto be received in the groove 7 formed in the shanks. 'The inner ends of these thickened portions are squared to provide stop members 27 which are adapted'to abut when the cutting blades are moved into final cutting position. By providing this stop means the cutting edges of the blades will be prevented from coming into violent contact with oneanotherand dulling the The stationary cutting blade is formed with a hole 28 throughitsupper portion for register with the holes formed in the arm 5 and is adapted to receive therethrou'gh a screw 29" for holding it in rigid position in 'the grooves (Sand 7;

The aforesaid ear 14:"formed on the rack bar 13'is adapted to receive one end of a spring 30 whose opposite end is secured to the eye 31so as to normally hold thecutting blades in spaced relation to one another, It 'will thus be seen that this spring will alwa s move the cutting blades apart when the cable secured leased. a v By roviding removable cuttin blades, said b ades may be conveniently s arpened at anytime or replaced, when worn out, by new blades. Particular emphasis is laid .on

to the operating arm 18 is rethe stop members rovided onthes'e cutting blades as well ast e means for securing the a u removable blades, in operative position in the device. Fromthe forgoing description of the construction of my improved pruning shears,

vthemanner of applying the same to use and the advantages thereof will'be readily understood, and "it will be seen that I have provided a simple and inexpensive, yet

eflicient device of thischaracter for carrying 1 out the objects ofthe invention; namely the long gradual tapered formation of the cutting blades from near the base thereof to the cutting edge, thereby securing a clean cut' through the wood without crushing the Wood and bruising the bark and the eccentric relation of the lever fulcrumwith respect'to the blade carrying member combined with the arrangement of this lever, so that it shall approach the position in line at right angles with the line of blade actuation, to increase the cutting power as the blades ap proach the meeting point, where the maximum resistance to the cutting" operation is presented by the object operated upon.

While I have particularly described the elements best adapted to perform the functions allotted to them, it is obvious that various changes in form, proportion, and in the minor details of construction may be resorted to within the scope of the appended claims without departing fromthe spirit or sacrificing any of the principles of theinvention.

Having described my invention, what I claim is a a a 1. In a prunin device, a housing having a longitudinal gui e passage, a handle atone endof saidhousing, a shank extending from i the other end, a stationary blade carried by said shank, a movable blade carrying mem, ber slidable in said guide passage, a blade on said member for coaction with the stationary blade, 'a rack bar contacting with said member, means for preventing longitudinal shifting of said rack relative to said member, a gear sector for coaction with the rack, said sector holding said rack bar and said member in cooperative engagement, whereby the latter is raised or lowered upon movement of the former, and means for operating said gear sector.

2111i a runing device, a a longitudi one end of said housing, a shank extending housing having nal guidefpassage, a handle at from the other end, a stationary blade car- I I ried by "said shank, a movable blade 'slidable in said guide] assag'e', and coacting with the stationary blade, a shank extending'from said movable blade with-in the guidepas sage, a rack bar having a groove in one of its longitudinal edges receiving one longi tudinal edge of the shank, means for preventing" longitudinal shiftingof said rack relative to said member, a gear sector for 'coaction with therack, said sector holding said rack bar and said shank in coeperative engagement, whereby the latter with its blade is raised or lowered upon movement of the former, and means for operating said gear sector; g

r 3. In a pruning device, a housing having a longitudinal guide passage, a handle at one end of said housing, a shank extending from the other end, a stationary blade carried by said shank, a movable blade carrying member slidable in said guide passage, and having a notch in one of its edges, a blade on said member for coaction with the stationary member, a rack bar contacting with said member, a stop carried by the bar for engagement with said notch to prevent longitudinal shifting of the parts, a gear sector for co-action with the rack, said sector holding said rack and said member against lateral movement, whereby the latter is raised or lowered upon movement of the former, and means for operating said sector.

4. In a pruning device, a housing having a longitudinal guide passage, a handle at one end of said housing, a shank extending from the other end, a stationary blade carried by said shank, a movable blade slidable in said guide passage and coacting with the stationary blade, a shank extending therefrom within the guide passage and having a notch on one of its edges, a rack bar having a groove in one of its longitudinal edges receiving one longitudinal edge of the shank, a stop within said groove engaging said notch to prevent longitudinal shifting of the members, a gear sector for coaction with the rack, said sector holding said rack bar and shank against lateral shifting, whereby the latter with its blade is raised or lowered upon movement of the former, and means for operating said sector.

5. In a runing device, the combination of opposite y acting cutting knives each having a gradually tapering formation from approximately the base to the cutting edge thereof, and means whereby a knife is moved with increasing power toward the meeting point where the maximum resistance to the cutting operation is presented by the object operated upon.

6. In a pruning device, the combination of oppositely acting cutting knives, lmife sup-- porting elements, one movable with respect to the other, means for actuating the movable supporting element, comprising an operating lever and a pivot support therefor, arranged and operated whereby the point of engagement between the weight arm of the lever and the movable supporting element approaches the fulcrum of the lever, and the power arm of the lever moves from a line parallel with the movement of the blades and approaches a line at right angles with said line of movement, as the knives approach the meeting point.

7. In a pruning device, the combination of oppositely acting cutting knives, knife supporting elements, one movable with respect to the other, means for actuating the movable supporting element comprising a rack, a cooperating sector gear, having an eccentric pivot, for engaging the rack, and an actuating lever connected with said gear, the parts arranged so that the point of engagement between gear and rack approaches the pivot, and the power end of th lever moves from a line parallel with the knife movement and approaches the line at right angles with a line of said movement, as the knives approach the meeting point.

78. The combination of oppositely acting cutting knives each having a gradually tapering formation from approximately the base to the cutting edge thereof, and means comprising an actuating lever and an eccentric actuator arranged to exert, in initial position, a minimum of power, and, in final position, a maximum of power, whereby the knives are moved with increasing power toward the meeting point where the maximum resistance to the cutting operation is presented by the object operated upon.

EMERSON MGKENNEY.

flopies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents, Washington, D. G.

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