US2562773A - Electric scissors - Google Patents

Description

July 31, 1951 J. c; CLARK ELECTRIC SCISSORS Filed May 29, 1945 TqZ.

Patented July 31, T951 UNITED STATES PATENT OFFICE ELECTRIC SCISSORS Application May 29, 1945, Serial No. 596,506

Claims. (Cl. 30-228) This invention relates to electric scissors, and particularly to those of the vibratory type, wherein the blades shear as functions of the cycles of alternative current fed to the scissors, for cutting cloth and the like.

vElectric scissors as previously constructed for commercial purposes have been open to certain criticisms, one of which was the fact that but one of the two shearing members or blades was actuated by the alternating flux in the instrument, while the other shear element or blade was passive and stationary relative to which the first shear element moved. This reduced the cutting rate. Another disadvantage was the relative inability either to establish, or later to reestablish, proper lateral and angular relations between the shear elements or blades, so that the initial setting of the blades was also the xed final setting of the blades regardless of wear or of accident to the blades, such as to cause bending thereof. Other disadvantages included the unfortunate angle necessarily produced between the hand of the operator holding the device and the blades thereof, which made use of the scissors an uncomfortable matter, and the weight and excessive vibration of such scissors were objectionable.

It is among the objects of this invention: to improve the art of electric scissors; to produce an electric scissors of extreme economy of production and of lightness in weight; to provide an electric scissors which is small, compact and powerful in its cutting eiciency; to provide an electric scissors in which both blades are vibrated in complemental shearing relation relative to each other; to provide an electric scissors with blades which in vibrating damp each other to reduce the vibrational effects of the device; to provide an electric scissors with simple adjusting means by which the blades can be adjusted in torsion as well as in angular disposition; to provide an electric scissors which has a simplified control device; to overcome the disadvantages of the prior art; and many other objects and advantages will become more apparent as the description proceeds.

In the accompanying drawings forming part of this description:

Fig. 1 represents a side elevation of the scissors with one handle member removed to show the interior and working parts therein.

Fig. 2 represents a transverse horizontal section through the device shown in Fig. 1taken on line 2'-2 thereof.

Fig. 3 represents a side elevation of the device of Fig. 1, from its other side with one side meming and adjusting portion of the generally U- shaped spring armature member.

Fig. 5 represents a detailed perspective of the spring armature device of the assembly showing in dotted lines two of the adjustments derivable from the screws or the like in the back portion thereof.

The scissors unit comprises a laminated core element I0, having lateral enlargements at each end comprising pole or eld pieces as at I I at the rear, and I2 at the front of the scissors. A coil I3 comprised of a suitable plurality of turns is wound on the core for developing magnetic flux, which, in its alternations, rhythmically energizes and deenergizes the core element I0 and hence the pole or eld pieces Il and I 2 with alternate polarities. A lead wire I4 extends from one end of the coil to an insulated flexible contactmaking and breaking element I5, mounted at the rear of the scissors on the lateral extension I9 of a plate I6, fastened to the side of the rear enlargement II of the core III. The return wire I 4 leads from the coil directly into the common cable I1 leading out of the rear of the instrumentality. A second flexible contact making and breaking element I8 is also insulatedly mounted on the plate I6, in juxtaposition to the first contact element I5, and the other lead 20 from the cable II is attached thereto. It will be understood that the cable I'I is to be attached to a suitable plug-in device, not shown.

The assembly of coil and core just described exclusive of the contact-making elements and their support, constitutes a main frame of the scissors to which all other parts and the enclosing case are attached.

A supporting plate ZI is mounted on the side of the rear field piece II, and has a frontend 22 extending laterally across the center of the front eld piece I2, which end extension carries ay median forwardly extending Vplate 23, transverse of and symmetrically between the upper face 24 and the lower face 25 of the front field piece, and preferably carries a resilient cushion, illustratively comprising a rubber band, or the like, 26', as a damping element. At its rear end, the plate 2I has a laterally extending terminal portion 26. The latter carries ears 2'I extending parallel to and inslightly spaced relation to the rear face 28 of the rear field piece I I of the core I0.

The armature device and support for the shear blades comprises a modied generally U-shaped resilient member comprising, in the views illustrated, a vertically disposed rear planar portion 30 comprising the transverse connection of the U, an upper arm 3| generally perpendicular to the portion 30, and a depending front extension 32 on arm 3|, generally parallel to the planar portion 30. At'the lower end of the rear planar transversef'connection portion 30 merges into the generally perpendicular lower arm 33, which latter has an upwardly projecting front angular extension 34. The vertical central connectingportion 30 is preferably provided with suitable apertures arranged in vertically spacedV pairs, eachv pair of which is disposed in a line transversely of the vertical portion 3D, and in registry with suitable juxtaposed apertures in the, plate 21 above and below the center, and at the center with apertures disposed in the angular extension 26 of the supporting plate 2|, in order to receive the anchoring and adjusting' screws to be de scribed.

The U-shaped spring element just described is assembled laterally upon the electro-magnetic frame assembly described, so as to substantially completely enclose same on the rear and top and bottom, as well as partially on the front thereof. In this position a left hand setscrew 35 and a right set screw 36 are-caused to enter thecentra] apertures of the planar plate portion and into the aligned apertures in the washer 29 and plate 26 between it and the end of the core member, to anchor the plate to the frame. anchoring meansissymmetrical between vibrating members, it is practically at a node-point which is substantiallyv freel fromA vibrations and thusl minimizes thedegree of vibration of theentire assembly and enhances both the life thereof and the comfort in using the instrumentality. As thus assembled the opposite spring arms 3| and 33 incline away fromeach other at the front.

due to the initial shaping andresilience of the armature unit prior to assembly with theframe. Aleft hand screw 31 and a lright handscrew 38 arethen attachedthrough registering apertures in the common plate 30 and the adjacent ears 21 vertically betweenv the central anchor and arm 3|, and these'are tightened so as to bring;

the free end 32` of arm 3| downwardly toward theV abutment 25` in the center of the front of theunit. This brings arm 3| into proper spacing from eld pieces and |2. 40and 4| arersecured in the registering apertures of the common plate 30 adjacent to the other arm 33 of the pair` of resilient arms, and these are also suitably tightened in adjacent ears 21 to bring the free end 34 of armature 33 into close adjacency to the abutment 26' and with the. ar.

mature 33 properly spaced fromA the eld pieces. It will be seen that as thetightening of the respectivev pairs of set-screws. 3T and 38, and 40 and 4| is against the resilience of the respective,

side arms 3| and 33 of the U-shapedunit relative to a median anchor point, close controlof the, angular relationships of the two spring arms relative to the pole pieces issecured. It will also beseen that a diierential tightening ofv the screws of either of the last twoinentioned pairs against the resilience of the respective arms will exert an eective twisting of the arms 3| 01 33, to cause any desired relative misalignment or angular deviation ofY the confronting front angular portions 32 and 34 respectively,- so that blades carried thereby areicaused to change their. relative; angular. resilient mutual engagement.

AS this;

Similar screws One blade of the assembly comprises the lower footed element 42, preferably, although not necessarily, carried by the lower spring arm 33, and which, preferably, is the lowermost blade of the assembly, having the upwardly presented cutting edge 43, mounted on the upstanding angular extension 34 of the spring arm 33, as by` means of an anchoring plate 44, mounted on and extending` forwardly perpendicularly from the extension 34. The cooperating blade 45 has the downwardly presented cutting edge 46, and ispreferably mounted on the depending portion 32 of thev upper arm 3| by means of supporting plate 4T perpendicular to that portion.

If; desired-the blades can be reversed so that the lower element 42 is mounted on the upper spring.l arm 3|, while the upper blade 45 can be mounted' on the lower arm 33, so that the shear blades can be alternately connected so that they will cut either when thegarmatures are drawn to themagnet or when they are released.

Ony suitable studs on the core element, side, - plates 48 and 50 comprising the housing or cas ing are attached to enclose the assembly, except for a small slot 5| in the front through which the blades extend, and a small aperture 52- in the top in which a button 5-3 is mountedand disposed for controlling the circuit through the coil. Button 53 is mounted on the forward end of a lever 54 pivoted asl at 55 tothe side of the core frame assembly at the rear end-thereof, and the free end 56 of the lever is disposed adjacent to the rst contact-making element I5, so asv to actuate-same toward the second contact-maker |8-when the button is ydepressed by the thumb of. the operator. A spring device 5'lnormallyvholds the button endzof thelever up with respect to the stops 58, against which latter the side anges 60 of the lever abut in thedepressed position ofthe. button. The resilience of the first contactmaking element 5 opens the circuit when the freeend 56 of the lever is withdrawn.

It Willbe understood that when the thumb 1ever,.or other switchdevice is used to close a circuitofalternating. current through the coil, the,

laminationsof the core will be magnetized withA one polarity, which will simultaneously pull both of the respective adjacent spring arms 3| and33f toward the corev pole pieces, comprised ofV the ends of. the core although only the front pole pieces will be so placed as to have appreciable effect, and will pull the blades toward each otherto cause relativeshearing motion between the` opposed edges 43 andk 46, and to cut the material introduced or fed betweenthe said edges. During reversal of the alternating current thesprings are permittedto function `to spring apart, to separate theblades, followed by reversal of the polarity of the4 pole pieces. Thus, as thev core4 is magnetized a` power strokeis applied to the shears, followed`v by a release-thereof under the resilience-ofthe spring arms. This action is inl dicatedin Eig. 3, in which` the dottedlines infdicate onan exaggerated. scale the relation of; the blades when the spring arms are pulled in together under the action of the magnetic ux, and the full line position indicates the separa tion of the blades under the resilience of the spring arms. As noted, under certain conditions this can be reversed so that the cutting stroke will be asaV functionof resilience instead of magnetic attraction if desired, while still maintaining the simultaneous actuation of both' blades.

Titv will-be understoodthat withV theadjustment.

`provided the lateral pressure between the blades is easily and readily adjusted by varying the differential adjustments of the pairs of screws 31 and 38, and of 40 and 4l. It will also be clear that the relationship of either arm 3l or 33 to the pole pieces of the core can be selectively varied, so that the motion can be either the symrnetrical motion of both blades to the same degree as disclosed, or to an lasymmetrical motion of both blades, by permitting one to have a closer relationship to the pole piece and therefore a stronger pull and motion than the other, and nally so that one can be prevented from moving at all, and the blade associated therewith becomes a stationary anvil relative to which the other vibrates.

it will be clear that the provision of the rubber cushion 2G serves to absorb the excess Vibrations of the two spring arms by permitting the ends of the angular extensions 32 and 34 to abut same at the end of their respective power strokes, and that the degree of clamping thus secured can be varied by adjusting the respective pairs of adjusting screws 31 and 38, and 40 and 4l, to bring the ends of the respective spring arms closer to or further from the damping cushion 26.

The line bisecting the overlapping blades in their shearing relation is acute to the longitudinal axis of the entire instrumentality and thus secures a comfortable position for the hand of the operator grasping the instrumentality with reference to the work, as indicated in Fig. 1.

The cheapness, lightness, compactness, and neatness of the assembly thus provided will be clear as will the fact that it is rugged, susceptible to minute adjustments so as to compensate for wear, and that it is extremely powerful in its cutting action, especially in view of the fact that the cutting stroke in the preferred form is the power stroke in place of the rebound stroke.

Having thus described my invention, I claim:

l. An electric scissors, comprising an electromagnetic unit formed of a coil, a laminated core operatively associated with the coil, and a pair of resilient armature arms of substantially identical masses, a backing plate integral with the resilient arms, means for mounting the backing plate in anchored relation to the core with the arms overlying said core for synchronous actuation thereby, means operative between the anchor and the resilient part of the arm for moving the arm against its resilience to an adjusted operative position relative to the core, a blade having an edge, means operatively associated with one arm for mounting said blade, a second blade having an edge, and means for mounting the second blade on the other arm, with the respective edges in crossed relation, said adjusting means comprising a pair of spaced screw devices arranged for differential vertical and lateral adjustment of the blades.

2. An electric scissors, comprising an electromagnetic unit comprised of a core and a coil, a double resilient member substantially enclosing said core and comprising a generally U-shaped member having side arms forming armatures and a transverse connection, means for anchoring the device relative to said core so that the side arms of the U-shaped member overlie the core, crossed blades mounted for movement with the free ends of the armatures, said anchoring means being substantially symmetrically disposed in the transverse connection between the side arms, and means on opposite sides of the anchor for forcing the armature arms toward the core against their respective resiliences.

3. An electric scissors, comprising an electromagnetic unit comprised of a core and a coil, a double resilient member substantially enclosing said core and comprising a generally U-shaped member, bent from a single strip of steel, having side arms forming armatures and a transverse connection, means for anchoring the member relative to said core so that its side arms overlie the core, crossed blades mounted for movement with the free ends of the side arms, said anchoring means being substantially symmetrically disposed in the transverse connection between the side arms, means on opposite sides of the anchor for forcing the armature arms toward the unit against their respective resiliences and for laterally adjusting the blades with respect to each other.

4. An electric scissors comprising a generally U-shaped member formed of generally parallel spaced arms having free ends with opposite ends of the arms joined by a transverse connection extending between the arms, a frame, means attaching the connection to the frame at a point dynamically symmetrical between the spaced arms, a'blade mounted on the free endY of one arm and extending therefrom away from the connection and having a shearing edge, a second blade mounted on the free end of the other arm juxtaposed to the rst bladeand extending from said free end of said other arm away from the connection, said second blade having a shearing edge extending across the shearing edge of v the rst blade in shearing relation thereto, supplemental means adjacent to said pontfor varying the physical relationship of said arms to the frame by pressure between the frame and said connection, and an electromagnetic unit mounted on the frame and straddled by said arms, said arms comprising armatures for the unit.

5. An electricscissors as recited in claim 4, wherein said supplemental means is disposed between the rst means and a side arm and comprises a pair of pressure-varying devices spaced laterally on opposite sides of the longitudinal center line of the connection extending between the frame and the connection for predeterminedly varying the physical relationship of the connection and frame both angularly and in torsion to respectively vary the point of crossing of the respective shearing edges and to modify the pressure relation between said blades.

JOSEPH C. CLARK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 157,156 Chaquette Nov. 24, 1874 1,228,838 Schutz June 5, 1917 1,798,756 Redfield Mar. 31, 1931 2,273,536 Pollak Feb. 17, 1942 FOREIGN PATENTS Number Country Date 479,652 Germany July 20, 1929 492,391 Germany Feb. 21, 1930 531,808 Germany Aug. 15, 1931

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