US2020567A - Mechanical movement shears - Google Patents

Description

Nov. i2, 1935.

RNOSKE A 2,020,567

MECHAN ICAL MOVEMENT SHEARS Filed Aug. 10, 1934 ijf 45 -w 4,3 20 "o 37 ifgl'nuuminllgg E 1 z 'i '//l//I/l/l//A J4 33 J5. y 4] 36 Il? E I IINVENTOR.

Runolyos/E Wm# MW ATTORNEY Patented Nov. 12, 1935 UNITED STATES PATENT OFFICE The present invention relates to improvements in shears or scissors and it has particular reference to barbers shears, alhough the principles involved may be readily used in connection with any other type of shears.

The principal object of the invention is to provide power-driven shears in which power is transmitted for operating the shears in such a manner that the transmitting of power does not in any way interfere with the convenient manipulation of the shears.

A further object of the invention is to provide a'poWer-driven pair of shears in which motion can be transmitted to the shears at diiferent speeds.

A further object of the invention is to provide a power-driven pair of shears in which the shears may be operatedat different shear openings.

A still further object of the invention is to provide a convenient manipulating means for shifting from one speed to another.

It is further proposed in the present invention to provide a novel mechanical movement for effecting transmission of motion to the shears at different speeds.

It is further proposed to provide certain structural improvements and arrangements tending to increase the economy, eiciency and convenience of use of the device.

The preferred form of the invention is illustrated in the accompanying drawing in which- Figure 1 shows a top plan view of my device,

Figure 2 a top plan View with a cover removed,

Figure 3 a vertical section taken along line 3-3 of'Figure 1,

Figure 4 a detail View in plan of a manipulating member for my transmission,

Figure 5 a vertical section taken along line 5--5 of Figure 4, and

Figure 6 a detail View in plan of a mechan-` ical movement used in my transmission.

While I have shown only the preferred form of my invention it should be understood that various changes or modifications may be made within the scope of the claims appended hereto without departing from the spirit of the invention.

In its preferred form my invention comprises a casing of suitable form convenient for manipulation within the hand of the operator, a pair of scissor blades 2 pivoted in a recess 3 in an enlarged wall 4 of the casing so that the lever arms 5 extend into the casing and an operating mechanism for the arms is confined in the casing.

The casing is shown in the drawing as being substantially flat and rectangular in form and comprising a bottom 6, a continuous wall 1, rising from the edges thereof and a removable cover 8 secured to the wall by means of screws 9. The scissors are pivoted in the enlarged section 4 of the wall as shown at I0. l;v

The operating mechanism Afor the scissors or shears comprises two cams II and I2 mounted within the casing between the arms 5 of the shears and on the longitudinal center line thereof, in spaced relation to one another. The cam II 10 which is nearest the pivot of the scissors is larger than the cam l2 and comprises two flat faces I3 and two circularly rounded faces I4 and is mounted with freedom of axially sliding movement in a recess I5 of a worm gear I6 which 15 latter is secured to the bottom 6 with freedom of revolving motion by means of a screw I'I having-a head I8 bearing on the bottom of the recess.

The cam is held against rotary motion relative tothe worm gear by means of two prongs I9 20 riding in vertical slots 20 in a shoulder 2I rising from the worm gear. A spring 22 urges the cam upward so, as to bring the cam faces into the plane of the arms, the cover Il limiting the upward movement. 25

' The cam has a, projection 23 rounded at its tip and rising centrally from the upper surface thereof by means of which it may be depressed as will appear later in the description. When the cam is in its uppermost position and is revolved it will operate the scissors twice for each revolution of the cam. When it is depressed the cam faces move out of the plane of the arms and will leave the same unaffected.

The cam I2 is mounted similarly to cam II but 35 has four flat faces 24 with intervening edges so that when this cam is revolved in active position, that is, while positioned in the plane of the blades, it will operate the scissors four times to each revolution of the cam. This cam is mount- 40 ed with freedom of sliding motion in the worm gear 25 which is also secured to the bottom of the casing by means of a screw 26 having a head 2l bearing on the bottom of a recess in the worm gear.` The cam is held against turning-movement of the slide.

in bringing about reciprocating motion of the arms.

The worm gear 25 is smaller than the worm gear I6 and is intended for revolving motion at higher speed.

For imparting rotary motion to either one of the worm gears I provide the transmission illustrated in detail in Figure 6 and also shown in Figure 2. This transmission comprises two worms or threaded elements 33 and 34 revolvably mounted in bearings 35 and 36 in axial alinement with one another and in meshing relation with the worm gears I6 and 25 respectively and a shaft 3l extending axially through the two worms. The worms may be held against endwise movement by any suitable means as by pins 38 projecting from the bearings into annular grooves 39 provided in the bearing faces of the worms. The latter are provided with confronting toothed heads 4U, and a clutch member 4| toothed at opposite ends is slidable on the shaft between the two worm heads for driving engagement with one or the other, the clutch member being revolvable with the shaft.

For manipulation of the clutch member and for simultaneous operation of the two projections 23 and 3| I provide the slide 42 illustrated in detail in Figures 4 and 5 and comprising a flat plate slidably secured to the bottom face of the cover 8 by means of two pins 43 riding in a slot 44 The latter has a thumb-piece 45 projecting through a slot 46 in the cover by means of which it may be operated, the two slots being parallel when the slide is in position. The slide is provided with a further slot 41 which is disposed along the longitudinal center line of the scissors and in line with the two projections 23 and 3|. II'he length of the slot is such that only one of the projections can be accommodated in the slot at one time and the slide tapers toward the slot from opposite ends as shown at 48 so that when the slide is moved in one direction the taper at one end will ride over one of the projections and depress the same and when the slide is moved in the opposite direction the opposite taper will ride over the other projection and depress the same.

The slide is also provided with a. fork 49 which enters a groove 53 in the clutch member and operates the latter for connecting one or the other of the worms to the shaft 31, which latter may receive rotary motion from any suitable source of power, not shown in the drawing.

The operation of the device is as follows: When the operator desires to use relativelyslow speed with large shear opening he presses the thumb piece 45 forward into the position shown in Figure 1 and he thereby causes the clutch member 4| to engage the worm 33 which, through the worm gear l revolves the cam At the same time the slot 41 of the slide 42 is moved to clear the projection 23 which rises under the influence of the spring 22 and brings the cam faces into the plane of the arms while the projection 3| is depressed and the cam faces of cam I2 are moved below the plane of the arms.

If the operator desires relatively fast speed with comparatively small shear opening he merely slides the thumb piece 45 in the opposite direction whereby the clutch member is made to engage the other worm which transmits rotary motion through the worm gear25 to the second cam l2. The movement at the same time depresses the projection 23 while allowing the projectlon 3| to rise for bringing the cam faces of its cam into the plane of the arms. The cam Il, though larger than cam I2 and although disposed closer to the pivot of the scissors, does not interfere with operation of the scissors by the second cam because the faces of the cam are underneath the plane of the arms when the second cam becomes active.

I claim:

1. A pair of shears having a cam revolvable between the arms thereof for operating the same and means for revolving the cam including a permanently meshed worm drive, a clutch and a shifting device for the clutch for rendering the worm drive active or inactive, the cam being movable axially for movement between active and inactive positions and the shifting device having means associated therewith for moving the cam axially when the shifting device is operated.

2. In combination, a casing, a pair of shears pivoted in a wall thereof with the arms of the shears projecting into the casing, two cams revolvable in the casing between the arms for operating the same, the cams being movable axially and having spring means for urging the same into the plane of the arms, an operating shaft having means for transmitting rotary movement to one or the other of the cams and a manipulating element for the transmitting means having means associated therewith for moving the inactive cam out of the plane of the shear arms.

3. In combination, a casing, a pair of shears pivoted in a wall thereof with the arms of the shears projecting into the casing, a gear wheel revolvable in the casing in a plane parallel to that of the arms and spaced therefrom, a. cam mounted in the gear wheel with freedom of limited axial motion between an active position in the plane of the arms and an inactive position outside of said plane, spring means urging the cam into active position, a member slidable in the casing and having an inclined face engageable with the cam for forcing the same into inactive position when the member is manipulated, and means for revolving the gear wheel.

4. A pair of shears having two arms and two cams revolvable between the arms for operating the shears, the cams being mountedV on spaced axes and one of the cams being mounted intermediate the pivot of the shears and the other cam and means for imparting rotary motion to one or the other of the said cams.

5. A pair of shears having two arms and two cams revolvable between the arms for operating the shears, the cams being mounted on spaced axes and one of the cams being mounted intermediate the pivot of the shears and the other cam, yielding means urging the cams into the plane of the arms, means for imparting rotary motion to one or the other of said cams and means for moving the intermediate cam out of the plane of the arms when the outer cam is rotated. 6. A pair of shears having two arms and two cams revolvable between the arms for operating the shears, the cams being mounted on spaced axes and one of the cams being mounted intermediate the pivot of the shears and the second cam and the second cam having more cam faces than the first cam, and means for imparting rotary motion to one or the other of the cams.

7. A pair of shears having two arms and two cams revolvable between the arms for operating the shears, the cams being mounted on spaced axes and one of the vcams being mounted intermediate the pivot of the shears and the second cam and the second cam having more cam faces than the first cam, and means for imparting rotary motion toy one or the other of the cams from the same source of power at dierent speed ratios.

8. A pair of shears having twol arms and two l cams revolvable between the arms for operating the shears, the cams being mounted on spaced axes and one of the cams being mounted intermediate the pivot of the shears and the second cam and means for imparting rotary motion to one or the other of the said `cams at different speed ratios.

RUDOLF NOSKE.

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