US3602988A

US3602988A - Electric scissors blades

Info

Publication number: US3602988A
Application number: US878099A
Authority: US
Inventors: Robert E Little
Original assignee: Arvin Industries Inc
Current assignee: Meritor Inc
Priority date: 1969-11-19
Filing date: 1969-11-19
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07

Abstract

Electric scissors having blades spring biased toward one another with antifriction buttons therebetween and pivotally connected by a pin. A threaded fastener is received by and extends into the housing and a collar and engages a tapped member which is pivotably attached to a fixed blade whereby rotation of the fastener moves the fixed blade with respect to the movable blade to alter the location of the cutting area along the cutting edges of the blades.

Description

United States Patent [72] inventor Robert E. Little Columbus, Ind.

[21] Appl. No. 878,099 [22] Filed Nov. 19, 1969 [45] Patented Sept. 7, 1971 [73] Assignee Arvin Industries, Inc.

Columbus, Ind.

[54] ELECTRIC SCISSORS BLADES 6 Claims, 4 Drawing Figs.

[51] Int. Cl B26b 15/00 [50] Field of Search 30/228, 222, 247, 267

[56] References Cited UNITED STATES PATENTS 1,806,555 5/1931 Gonsett 30/228 2,731,721 -1/l956 Traurig 30/228 3,474,534 10/ 1969 Murphy 30/228 FOREIGN PATENTS 1,058,104 11/1953 France 30/228 Primary ExaminerRobert C. Riordon Assistant Examiner.l. C. Peters Attorney-Trash Jenkins & Hanley ABSTRACT: Electric scissors having blades spring biased toward one another with antifriction buttons therebetween and pivotally connected by a pin. A threaded fastener is received by and extends into the housing and a collar and engages a tapped member which is pivotably attached to a fixed blade whereby rotation of the fastener moves the fixed blade with respect to the movable blade to alter the location of the cutting area along the cutting edges of the blades.

PATENTED SEP 7 l97| "IIIIIIIIIIIIM ELECTRIC SCISSORS BLADES BACKGROUND OF THE INVENTION Electric scissors blades are normally much shorter than the blades on hand operated scissors and therefore require a greater number of strokes to cut a given length of material. This characteristic, together with the speed at which the blades operate, causes a great deal of friction between the blades which decreases both their cutting power and useful life. The cutting area, where the cutting edges of the blades actually perform their work, is a relatively small area. A large segment along the lengths of the cutting edges perform little if any actual cutting work. Consequently, the cutting area is much more subject to damage and wear than the other portions of the cutting edges. Sharpening the cutting edges is difficult and expensive. Once the cutting area is damaged or worn the scissors have virtually lost their utility, often necessitating replacement of the blades. This invention provides an improved construction for electric scissors blades in which the location of the cutting area can be altered along the cutting edges of the blades, thus increasing their cutting efficiency and increasing their useful life. By making adjustments periodically or as the cutting edges become worn or damaged, greater lengths of the cutting edges can be put to work.

SUMMARY OF THE INVENTION In accordance with one form of the invention an electric scissors includes a housing having an electromagnetic actuating device mounted therein. A threaded fastener is received by and extends into the housing and a collar and engages a tapped member, conveniently a nut, which is pivotally attached to a surface of a fixed blade supported in the housing and projecting outwardly therefrom. A movable blade also projecting outwardly from the housing is connected to the actuating device for movement thereby and is pivotally connected to the fixed blade to form a scissors.

The blades are connected together by a pivot pin carrying a spring to bias the movable blade toward the fixed blade. A plastic bearing is mounted on the pivot pin with the movable blade carried thereon to minimize frictional losses. At least one plastic button is mounted on one of the blades rearwardly of the pivot pin and engages the other blade to act in combination with the spring for urging the blade cutting edges into an abutting relationship. Thus, the only metal-to-metal contacting surfaces between the blades are at their cutting edges. This construction minimizes friction between the blades and permits the location of cutting area between the blades to be moved along the cutting edges of the blades by rotating the threaded fastener. Y

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in the accompanying drawings in which:

FIG. 1 is a side elevation of an electric scissors embodying the invention, with portions thereof being broken away and with another location of the cutting area illustrated by dotted lines;

FIG. 2 is an enlarged sectional view taken along lines 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary view showing the fastener and its engagement with the tapped member; and

FIG. 4 is an enlarged fragmentary sectional view of the fixed blade and tapped member.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, an electric scissors is provided with a housing 12. A movable blade 16 is pivotally connected to a fixed blade 14 by a transverse pivot pin 18 normal to the planes of the blades. Each blade has a front portion 17 disposed forwardly of pin 18 and provided with a cutting edge 19 and a rear portion 20 disposed rearwardly of said pin with the front portions of said blades projecting through an opening in the housing. I

A tapped member, such as nut 37, is pivotally attached to a surface of blade 14 as illustrated at 38 (FIG. 4). A threaded fastener 39 is received in a nonthreaded opening 40in housing 12. Fastener 39 extends through the opening and inside of housing 12, passes through a collar 42, and engages nut 37. The axis of the opening 49 in nut 37 and fastener 39 are parallel to the-plane of blade 14. The fastener has a slot 54 in its head end which is external of the housing. The housing is preferably provided with a countersunk portion to receive the head of fastener 39.

The blade 16 is swung about pin 18 by a conventional electromagnetic actuator 21 mounted with the housing. As shown, the actuator comprises a C-shaped magnetizable core 23 wound with a coil of wire 24. The ends of the coil are adapted for connection to an alternating current source (not shown) through a switch 26. An armature 27 comprising a highly permeable metal bar is disposed in spaced relation adjacent the pole faces 28 of the C-core 23 and is held in that position when the actuator is deenergized by an L-shaped spring 30 having one leg 32 attached to the armature and its other leg 34 attached to the C-core 23. When the electromagnet is energized, as by closing the switch 26, the armature 27 is drawn toward the pole faces 28, and then as the coil current changes direction the spring 30 pulls the armature away from the pole faces. The blade 16 is provided at its rearward end with a pair of tabs 36 connected to the end of the armature remote from the spring 30. Thus the movement of the armature is transmitted to the blade 16 causing it to swing about the axis of pin 18 to provide the desired cutting action at the cutting area, indicated at 45, where the cutting edges 19 are in an abutting relationship.

As described above, the blade 16 is connected to the armature 27 and pivotally connected to the fixed blade by means of the pin 18. The pin 18, which extends through both blades, has shoulders 41 adjacent its ends in spaced relation to the blades. The extended portions 46 of the pin 18 are seated in openings 47 formed in housing 12. A bushing or sleeve bearing 43 formed from an antifriction plastic material, such as nylon, Teflon or the like, is mounted on the pin 18. As shown in FIG. 2, the bearing 43 is interposed between the blade 14 and a shoulder 41 with the blade 16 carried thereon. A spring 44 is disposed around the bearing 43 with one of its ends bearing against housing 12 adjacent a shoulder 41 and its opposite end bearing against blade 16 urging said blade 16 toward blade 14.

In order to further force the cutting edges 19 of the blades into an abutting relation at their intersection, two antifriction buttons 48 are mounted on the blade 16 in radially and angularly spaced relation to pin 18 rearwardly thereof. These buttons are conveniently formed from the same material as the bearing 43 and project outwardly from blade 16 to ride against blade 14. The buttons provide an equilibrium to the blade structure such that there is no stress put on the armature 27 except the resistance to pivotal movement. This resistance to pivotal movement is minimal, however, since there are only four movable contacting surfaces in the blade assembly and only the cutting edges 19 are in metal-to-metal contact. The remaining three surfaces, that is the abutting surfaces of blade 16 and bearing 43, and those of the two buttons 48 and blade 14 are plastic to metal bearing surfaces.

When it is desired to alter the location of the cutting area, thus utilizing different portions of the cutting edges, fastener 39 may be rotated slightly as by a screwdriver or a coin inserted into slot 54. The fastener rotates but does not move into or out of housing 12. As the fastener is turned, nut 37 will advance or retreat along the threaded shank of the fastener, and in so doing, pivoting about its connection to blade 14. As the nut moves with respect to the shank of fastener 39, it shifts the position of blade 14 about pivot pin 18. This changes the relative positions of cutting edges 19 of

blades

14 and 16, thus altering the location of the cutting area 45 accordingly, as illustrated in dotted lines in FIG. 1. The cutting relationship between the cutting edges 19 is maintained.

cutting: edgesof one of said blades towardlthe' cutting; edge of the other, a. tapped member pivotabl-y: connected tovsaid. first blade, a fastener received. in. said housing with one end exteriorly thereof, said. fastener threadably engaging said tapped member so thatirotation of said fastener'alters the location of the cutting area along said cooperativeacutting edges;

2. Therinvention as set forth in claim 1. wherein said tapped rnember'is disposed'rearwardly of said pin.

3. The invention: asset forth in claim 1 wherein the axis of the opening: said tappedmember and saidfastener are paralleltothe'piane of'said first' blade.

A". The invention as set forth inclaim 1 wherein saidfast'ener is-retained by a collar and threadably engages a nut pivotably connected to said first blade;

51 Thei'nventibnas set forth-in"claim"- 1 wherein said pin has a shoulder and an extended portion which is seated in an opening in said housing.

6". Theinvention as set forthin claim 5 wherein said biasing means comprises a coil springrdisp'osed between said second blade and said housing adjacent saidshoulder.

Claims

1. An electric scissors comprising a housing, electrically operated actuator means mounted in said housing, first and second blades, a pin connecting said first and second blades, said second blade being swingably supported on said pin and connected to said actuator means for movement with respect to said first blade, said blades having cooperative cutting edges disposed forwardly of said pin, biasing means urging the cutting edges of one of said blades toward the cutting edge of the other, a tapped member pivotably connected to said first blade, a fastener received in said housing with one end exteriorly thereof, said fastener threadably engaging said tapped member so that rotation of said fastener alters the location of the cutting area along said cooperative cutting edges.

2. The invention as set forth in claim 1 wherein said tapped member is disposed rearwardly of said pin.

3. The invention as set forth in claim 1 wherein the axis of the opening in said tapped member and said fastener are parallel to the plane of said first blade.

4. The invention as set forth in claim 1 wherein said fastener is retained by a collar and threadably engages a nut pivotably connected to said first blade.

5. The invention as set forth in claim 1 wherein said pin has a shoulder and an extended portion which is seated in an opening in said housing.

6. The invention as set forth in claim 5 wherein said biasing means comprises a coil spring disposed between said second blade and said housing adjacent said shoulder.