US1388439A - Animal-shears - Google Patents

Description

C. M. PALMER.

ANIMAL SHEAHS.

APPLxcATloN FILED SEPT. 3, 191s.

Patented Aug. 23, 1921.

UNITED STATES PATENT OFFICE.

ANIMAL-SHEARS.

Specication of Letters Patent.

Patented Aug. 213, 1921.

Application filed September 3, 1918. Serial No. 252,385.

To all 'w wm t may concern?,

Be it known that I, Cnns'rnu Moses PALMER, a citizen of the United States of America, and a resident of Aurora, county of Kane, and State of Illinois, have invented certain new and useful Improvements in Animal-Shears, of which the following is a specilication.

My invention relates to improvements in that class of animal shearing machines in which the oscillating cutter lever is mounted at a liXed angle on a pivot shaft having rotative bearing in the upper and lower walls of the shear casing or frame, and a hand operated tension screw for adjusting the tension pressure on the movable cutter and the object of my present invention is to provide a means of variably increasing the adjusted tension pressure upon the movable cutter in proportion to the varying cutting resistance of the haii: or wool of the animal being shorn.

In the device illustrated in the accompanying drawings, the herein described improvement-s are shown embodied in animal shears of that type covered by U. S. Patents Nos. 877,517 and 1,282,459 issued to me on January 28th, 1909, and October 22nd, 1918, both of which illustrate, a hand operated tension screw for adjusting the tension pressure on the movable cutter, and also a means of equalizing said tension pressure upon the different teeth of the movable cutter, while in addition to the above, my present invention provides a means by which the adjusted tension pressure on the movable cutter is variably and automatically increased by and in proportion tothe varying cutting resistance of the hair or wool of the animal being shorn.

Most all shearing machines have a hand operated tension screw which is notched to provide a vertical adjustment of from two to .five thousandths of an inch, to provide an increased tension pressure as the cutters become dulled by use, and it requires about an equivalent increase of tension pressure to cut the heavier wools as smoothly as the lighter wools of an animal, and I find by experiments that I can produce such required increase of tension pressure automatically, in that class of shearing machines described by making one or both of the pivot shaft bearings from four to ten thousandths of an inch larger in diameter than the corresponding part of the pivot shaft, the

amount of excess play required being determined largely by the design of the machine.

The usual mechanical allowance for such bearings being from one to two thousandths of an inch.

In using the ordinary shearing machine, the operator usually sets the tension only tight enough to cut the lighter wools smoothly, with the result that the heavier wools are partly broken or torn off leaving a ruffled and ragged appearance, or if the tension is set tight enough to cut the heavier wools smoothly, the excessive friction causes the machine to heat and dulls the cutters very quickly. In operating a shearing machine embodying my present invention the tension need only be set tight enough to cut the lighter wools smoothly, the tension pressure on the movable cutter heilig automatically increased by the cutting resistance of the heavier wools which are thereby cut smoothly, and the machine operates with a comparatively light empty.

An illustrative embodiment of this invention is shown in the accompanying drawings, in which- Figure .l isa plan of a pair of animal shears embodying this invention.

Fig. 2 is longitudinal sectional elevation same taken on line 2 2 of Fig. l.

F ig. 3 is a fragmentary sectional detail taken on a line 3-3 of Fig. 2.

Fig. il is substantially a section taken on line 4l-4 of Fig. 2;

Fig. 5 is a lragmentary view, partly in section, showing a modified arrangement of tension while running the shaft in its lower bearing;

F ig. 6 is a bottom view of the parts shown in Fig.

Similar numerals refer to similar parts throughout the several views.

Secured to the forward end of the casing or frame l is the comb or fixed cutter 6 in contact with which the movable cutter 5 is adapted to be oscillated by the lever 3 which is centrally mounted on a pivot shaft 2 which is rotatively journaled in bushings 7 and 8 having screw' threaded connection respectively with the upper and lower walls of the frame 1.

The pivot shaft 2 has upper and lower cylindric portions which have rotative bearing respectively with the bushings 7 and 8 before referred to, and extends through a vertical opening 11 in said cutter lever, an

annular shoulder 9 and a flat sided shoulder are formed on the vshaft near the middle thereof but spaced apart axially so that when the shaft 2 and the lever 3 are assembled the shoulder 9 will fit in the tapered bore 11 at ak point below the longitudinal center o-f the lever 3 andthe shoulder 10 will contact with a flattened surface or shoulder 12 formed on the lever 3 above said longitudinal center, forming la vertically vseparated two point Contactv between the said shaft and lever to maintain them at a fixed angle, and the latter is adapted to rock slightly relatively to the shaft, so that the forked end of the lever will bear uniformly on the movable cutter 5. Said lever 3 is provided at its rear end with a vertical socket 14 in which operates a ball 4`mounted on a. Vcrank pinvextending forwardly and eceentrieally from the driving crank shaft 15, whereby oscillato motion is given tosaid cutter lever and e cutter carried thereby, through the rotarylaction of said shaft. Y v

yThe tension exerted on said cutter lever to maintain the movable cutter in proper relation to the fixed comb, or cutter isef'fected through the pivot shaft'2, and the construetion and arrangementof the parts are such that the oscillatory cutter lever is maintained at all times atafixed angle to the pivot shaft 2 Vand all tension applied thereto is exerted oni-the front end of thelever to hold the f movable cutter against the fixed cutter, while the rear end ofthe lever is freel from engagement with a friction surface. The construction of the parts, however -is such that the cutter leveris free to rock slightly on its longitudinal axis to permit itito properly adjust'itself and the cutter carried thereby. to maintain a uniform contact of the movable `cutter with 'the fixed comb Orcutter as has been fully set forth and claimed in my Patent No. 877,517, issued January 28th, 1909.

The manually operated tensioning means comprises an internally threaded cap 16 and a pin 17 interposed between the said cap and the shaft 2. The cap 16 has threaded engagement with'the bushing 7 in axial alinement with the shaft 2 and is provided with a notchedfiange'lS with which the spring 19 2 and rests upon a ball 23 seated in the bore 22.'- The diameter of the pin v17 is less than that of the bore 22 and by reason ofthe pivetal `mounting'of the pin 17 there is the least .possibleamount of resistance to the shifting of the shaft 2 which will be more fully explained; f v

f'Te provide a means' of automatically increasing the adjusted tension pressure on the movable cutter, as is required to cut the heavier wools of an animal smoothly, either the upper bearing 7 or the lower bearing 8 or both bearings are formed from four to ten thousandths of an inch larger in diameter than the corresponding party of the pivot shaft 2,`the amount of such excess play required depends largely on the design of the machine. It will be understood that it will require less excess play if provided in both of the bearings than if in one only.

In the device shown in Fig. 2 the upper bearing 7 is formed from seven to ten thousandths of an inch larger in diameter than the corresponding part of the shaft 2 and the lower bearing 2 is formed with the usual mechanical allowance of from olie to two thousandths of an inch play.

Referring now to Fig. 2 for an explanation as to why the provision of a certain amount of excess play between the pivot shaft and its bearings affords the desired automatic increase of tension pressure upon the movable cutter required to cut the heavier wools of an animal smoothly, it will be seen that the shaft with the adjustable tension normal rests at its upper end against the rear face of the bearing in the bushing 7 and at its lower end against the front face of the bearing formed in the bushing 8. This condition is due to the fact that the tensioning force is made effective upon the lever 3 through the medium of the vertically separated two point contact of the shaft 2 with the lever 3. The pivot shaft 2 bears upon onlyA a very small are of the bearing surface formed in the bushing 7 having a free space on each side and in front of the shaft as is clearly shown in Fig. 4, allowing the upper end of the shaft to be shifted laterally and thereby forwardly under the infiuence of the rotating crank pin and ball 4 which a plies its force to the lever 3 in a lateral irection. The direction ofthe shifting or tilting of the shaft laterally corresponds at all times to the direction in which the crank pin is at that time applying lateral pressure upon the lever,and the greater the force applied laterally to the lever due to the cutting resistance of the hair or wool being cut, the greater the shifting of the shaft laterally and forwardly at the upper end, and rearwardly at the lower end if excess play is provided in the lower bearing, thereby increasing the tension pressure on the movable cutter in proportion to the force required to oscillate the said cutter lever.

The usual allowance of play provided in the pivot shaft bearings of shearing machines of the class described does not produce any comparative or practical increase of tension, but the greater the amount of excess play provided the greater will be the increase of tension 'pressure in proportion to CIK -ried thereby may the cutting resistance of the hair or wool, and the exact amount of excess play required to provide the desired increase of tension pressure on the movable cutter to cut the heavier wools of the animal smoothly, will vary in differently designed machines.

l claim :h

l. A shearing,` machine comprising a easing, a xed comb or cutter, a cutter movable en said fixed cutter, an oscillatory cutter lever, a pivot shaft having` rotative bearing in the ripper' and lower walls of said casing and non-rotatively engaging between its ends said lever, one of said pivot shaft bearings formed relatively larger in diameter than the corresponding,l part of said shaft, whereby a comparatively increased tension may be provided automatically by the op` eration ofthe machine, an adjustable tension screw having,` threaded engagement with said casing` in axial alinement with said pivot shaft, a pivot pin interposed between said tension screw and pivot shaft for applying tension to the lever through said shaft, ineansiwhereby the lever and the cutter carhave a slight rocking movement with respect to the shaft to permit uniform pressure of the cutter' on the fixed comb, means whereby a fixed angle between said pivot shaft and lever is maintained, and means for oscillating said cutter lever.

2. In a shearingr machine, the combination with a casing', a fixed comb or cutter, anda cutter movable on said fixed comb, of a pivot shaft journaled at its ends in the upper and lower walls of said easing, an oscillatory cutter lever mounted at a fixed angle mediate the ends of said pivot shaft, means for applyingv an adjustable tension pressure to said lever through said shaft, said pivot shaft bearings relatively larger in diameter than the corresponding' parts of said shaft whereby a comparatively increased tension may be provided automatically by the operation of the machine, means whereby the forward end of said lever and the cutter carried thereby may have a slight rocking movement to permit uniform pressure of the cutter on the fixed comb, and `a means of oscillating said lever.

3. In a shearing machine the combination with a casing', a fixed comb or cutter, and a cutter movable on said fixed comb, of a pivot shaft having rotative bearing in the upper and lower walls of said casing, an oscillatory cutter lever mounted at a fixed angle, mediate the ends of said shaft, an adjustable tension screw having threaded engagement with the casing in axial alinement with said pivot shaft, a pivot pin interposed between said tension screw and said pivot shaft, to apply tension to the lever through said shaft, said pivot shaft bearings relatively larger :in diameter than the corresponding` parts of said shaft whereby a comparatively increased tension may be provided automatically while cutting' the hair or wool of' an animal, means whereby the forward end of said lever and the cutter carried thereby may have a slight rocking movement with respect to said shaft to permit uniform pressure of the cutter on the guard plate, and means for oscillating aid lever.

4. In shearing machines, the combination with a casing, a fixed comb, and a cutter movable on said fixed comb, of a pivot shaft having rotative bearing),r in the upper and lower walls of said casing, an oscillatory cutter lever mounted at a fixed angle mediate the ends of said pivot shaft, an adjustable tension screw having threaded engagement with said casing in axial alinement with said pivot shaft, a pivot pin interposed between said tension screw and saidshaft to apply tension to said lever through said shaft, and means whereby the front end ofv said lever and the cutter carried thereby may have a slight rockingV movement to permit uniform pressure of the cutter on the fixed comb.

Signed at Aurora this 29 day of Aug.,

CHESTER M. PALMER.

Images