Electric Scissors

Abstract

Electric scissors having a stationary blade and an oscillating blade driven by a motor, all mechanical and electrical parts, particularly the scissors, motor and battery being accommodated and mounted in a handle-shaped casing made of two assembled parts of plastic material without any screw-fastened portions by means of elastic portions latched to the casing, and all of said mechanical and electrical parts being readily exchangeable.

Description

This invention relates to scissors having a stationary scissors blade and an oscillating scissors blade. Prior scissors of this type are complicated in construction and maintenance and in many cases unhandy.

It is an object of this invention to provide electric scissors which is simple and cheap in manufacture, which may be readily disassembled for attendance or repair, which has high lifetime and high efficiency and which is very handy and simple in use. The electric scissors according to this invention broadly comprise a handle-shaped casing in two parts, a battery being shifted into the rear part of the casing and a motor being shifted into a forepart of the casing and said battery and motor being secured in position when said casing parts are assembled, and the scissors being inserted into the forepart of the casing from outside and secured therein by means of a stop bracket latched on the foreportion of the casing.

An embodiment of the invention will now be explained in detail with reference to the accompanying drawing wherein

FIG. 1 is an axial vertical section of the important part of the scissors,

FIG. 2 is a partial view similar to FIG. 1 on a larger scale and with the scissors removed and

FIG. 3 shows the scissors partially in horizontal section, partially in top view.

The illustrated apparatus has a casing of plastic material including a forepart 1 and a rear part 2. The rear part, of which only a small portion is shown, is in fact somewhat longer than the forepart and it is somewhat tapered towards its rear end not shown in the drawing. It serves for accommodation of a battery formed by two cylindrical elements, whereby the one terminal of the rear element contacts a metallic inner liner 3 of the rear part 2. Casing parts 1 and 2 are interconnected by means of a bayonet joint.

The mechanical parts of the scissors are mounted in and on the forecasing part 1, such parts including a stationary scissors blade 4, an oscillating scissors blade 5 and a motor 6. A slide pad 7 is removably applied on to the stationary blade 4. A pivot shaft 8 for the oscillating blade 5 is riveted to the stationary blade 4. A pressure spring 9 is inserted between the one wider end of shaft 8 and the oscillating blade 5, the latter being thereby urged against the stationary blade 4. A slide disc 10, for instance a foil of Teflon is inserted between blades 4 and 5. Experiments have shown that without such a slide disc the blades are worn too rapidly and the friction between the blades is so high that the efficiency is extremely low. The widened ends of shaft 8 are seated in approximately semicylindrical seats or pans 11 of the casing part 1, the shaft being maintained in its position by means of a resilient stop bracket 12. This stop bracket 12 is clamped by its own elasticity between an upper support 13 having a pin 14 engaging an aperture of bracket 12 and a lower support 15, whereby the lower curved end 16 of bracket 12 is latched behind the support 15. If this curved end 16 is slightly bent back the bracket 12 may be removed and the scissors may also be removed for sharpening or replacement.

The stationary blade 4 has an anchoring arm 17 extending through a slit of bracket 12 into a recess 18 of the forecasing part. In this way the blade 4 is secured on the casing in a determined position. The oscillating blade 5 has a drive arm 19 extending into the casing, the inner end of this arm forming a fork with inner bearing surfaces 20 of circular shape. An oblong transmitting element 21 of nylon or the like is pivotably mounted with its cylindrical bearing surfaces in said bearing surfaces 20 of arm 19. The bearing surfaces of element 21 are formed in a groove into which the legs of the fork formed at the end of drive arm 19 engage with little clearance, such that the transmitting element 21 is secured against lateral displacement in arm 19 but is able to swing round an axis parallel to the pivot shaft 8. As may be seen from FIG. 3 the transmitting element 21 has an oblong opening 22 of a width approximately equal to the diameter of an eccentric drive pin 23. This drive pin 23 is mounted on the shaft of motor 6 by means of a hub 24.

The motor 6 has a first terminal 25 and a second pot-shaped terminal 27 fixed to an insulated bearing flange. Two orienting pins 28 formed on the forecasing part engage recesses at the front portion of the motor. The motor 6 is axially secured between a shoulder of the casing near the pins 28 and a stop ring 29 inserted into the rear end of the forecasing part 1. A metal ring 30 is assembled with an annular insulating support 29 of this stop ring, said metal ring 30 having two contact springs 31 extending rearwardly and having stamped latch springs 32 and a forwardly extending contact spring 33. The latch springs 32 snap into apertures 34 of the forecasing part when the stop ring 29 is inserted into the casing, whereby this stop ring and the motor 6 are secured in axial direction. Springs 31 contact the inner metallic coating 3 of casing part 2 and thus are electrically connected to the one terminal of the battery.

Contact spring 33 is located between the terminal 25 of motor 6 and a ball loosely inserted into an aperture of casing part 1. This ball engages a recessed portion 36 of a switch slider 37. The recessed portion 36 is deeper at its fore-end than at its rear end. The switch slider 37 is mounted in a dovetail groove open at the rear end of the casing part 1 and is secured in this groove by the ball 35 engaging the recessed portion 36 and by casing part 2.

In FIG. 1 the scissors is illustrated in operating condition. The switch slider 37 is shifted into its foreposition and the ball 35 is urged inwardly by the shallow portion of recess 36 whereby contact spring 33 is pressed inwardly onto the motor terminal 25. The motor 6 is thus connected to the battery through the metallic coating 3, contact springs 31, ring 30, contact spring 33 and terminal 25 and through the terminal 26 and contact pot 27 to the other terminal of the battery not shown in the drawing. A vertical oscillating movement is imparted to the transmitting element 21 by the rotating drive pin 23, this oscillating movement being transmitted to the drive arm 19 of the scissors blade 5. A transmission practically without play between the transmitting parts and consequently practically without noise is obtained between the motor and the oscillating scissors blade, because the variable inclination of the drive arm 19 is compensated by a slight swinging movement of the transmitting element 21 in the fork arm 19. During use of the scissors the pad 7 slides over a supporting surface, for instance a table, while the material to be cut is fed between the scissors blades and is cut by them. The amplitude of the scissors blade 5 is relatively low so that its movement is not hindered by pad 7. For replacing or sharpening worn scissors may be removed in a simple manner. After removal of bracket 12 the scissors may be pulled out of the casing. Replacing of the battery is equally simple, it being only necessary to separate the casing parts by opening the bayonet joint between them, replacing the battery in casing part 2 and reassembling the casing parts. Even replacement of the motor 6 is very simple. After removal of the rear casing part 2 the latch springs 32 are urged inwardly by means of a suitable instrument, whereafter the stop ring 29 may be removed. The motor now falls out from the casing and may be reinserted after attendance or replaced by a new motor by simply shifting it into the casing. Due to the particularly simple assemblage of the scissors, manufacture of the same is very economic. The high lifetime and low power consumption has already been mentioned above.

Claims

What I claim is:

1. Electric scissors having a stationary blade and an oscillating blade and comprising in combination a handle-shaped casing in two parts, a battery being shifted into the rear part of the casing and a motor being shifted into a forepart of the casing and said battery and motor being secured in position when said casing parts are assembled, and the scissors being inserted into the forepart of the casing from outside and secured therein by means of a stop bracket latched on the foreportion of the casing.

2. Electric scissors according to claim 1, wherein a stop element for the motor is latched with retaining springs in openings of the forecasing part, said stop element having contact springs for connection of the motor to the conducting inner side of the rear casing part.

3. Electric scissors according to claim 2, wherein said stop element has an annular portion of insulating material, a metal ring with latch springs and contact springs being fixed on said annular portion.

4. Electric scissors according to claim 1, wherein a switch slider is shifted into a groove open at the end of one casing part, said groove being closed at its open end by the other of said casing parts.

5. Electric scissors according to claim 4, wherein said switch slider acts on a contact spring through a pressure-transmitting element, for instance a ball, loosely inserted into a bore of the casing wall.

6. Electric scissors according to claim 1, wherein an eccentric drive pin of the motor shaft engages an opening of a transmitting element swingably mounted on a drive arm of the oscillating scissors blade round an axis parallel to the oscillating axis of the scissors blade.

7. Electric scissors according to claim 6, wherein said drive arm of the scissors blade forms a fork in which said transmitting element is swingably mounted.

8. Electric scissors according to claim 1, wherein said stationary blade has a pivot shaft for said oscillating blade, said stationary blade having an anchoring arm engaging a recess of said forepart of the casing and said oscillating blade being urged against said stationary blade by means of a spring.

9. Electric scissors according to claim 8, wherein a slide disc, for instance a Teflon disc is inserted between said blades.

10. Electric scissors according to claim 8, wherein said pivot shaft is mounted with its ends in bearing pans of the forepart of the casing, said shaft ends being held in said bearing pans by said stop bracket.

11. Electric scissors according to claim 1, wherein a slide pad is removably applied to said stationary blade.