US2533946A

US2533946A - Portable vibrator-type tool

Info

Publication number: US2533946A
Application number: US735869A
Authority: US
Inventors: George N Levesque
Original assignee: Brown and Sharpe Manufacturing Co
Current assignee: Brown and Sharpe Manufacturing Co
Priority date: 1947-03-20
Filing date: 1947-03-20
Publication date: 1950-12-12
Anticipated expiration: 1967-12-12

Description

12, 5 s. N. LEVESQUE 2,533,946

PORTABLE VIBRATOR-TYPE TOOL Filed March 20, 1947 2 Sheets-Sheet 1 Zh aerator eor e/[Zeaesaue 1950 G. N. LEVESQUE 2,533,946

PORTABLE VIBRATOR-TYPE TOOL Filed March 20, 1947 2 Sheets-Sheet: 2

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Patented Dec. 12, 1950 72,533,946 PORTABLE VIBRATOR-TYPE TOOL George N.

. Brown and Levesque, Cranston, It. I.,.assignor to Sharpe Manufacturing Company,

a corporation of Rhode Island Application March '20, 1947, Serial No. 735,369 13 Claims. (01. 172-126,)

The present invention relates to improvements in portable tools of the general type having a vibratory electromagnet and armature motor arranged for driving a rapidly oscillating or vibrating tool member, and is more particularly concerned with the provision of an improved hair clipper having a vibrator-type motor adapted to be driven from an alternating current source.

For use in hair clippers and similar tools having a rapidly vibrating tool member, the magnet and armature vibrator-type motor has many advantages, which include cheapness of construction, simplicity, long life, and the further desirable characteristic that there are no contacts or brushes to cause radio interference. Motors of this type, however, have been found to have serious disadvantages in that they normally opcrate at twice the current frequency which for a sixty cycle alternating current is 7200 vibrations per minute, tend to excessive vibration and noise, and have poor regulation characteristics which tend to cause the blades to stall with a drop in line voltage or increase in load and, conversely, tend to cause excessively large motions with an increase in line voltage or decrease in load.

Principal objects of the invention are toprovide a hair clipper or similar device having a vibrator-type motor which is adapted to operate at the frequency of the supplied alternating current, usually 3600 vibrations per minute, and which is further constructed and arranged to operate substantially without external vibration of the clipper casing, and with a maximum power output of the device under widely varying conchtions of voltage and current input, and vfor any reasonable variation in load imposed upon the clipper in operation.

Specifically, it is an object of the invention to provide in a portable tool assembly including a vibratory tool member, a novel and improved construction and arrangement of an armature-type motor adapted to provide for a broadly effective regulation of the device to compensate for unavoidable changes in Voltage and load imposed upon the tool in operation, and thus to maintain continuous operation of the tool at a maximum power output.

It is a further object of the invention to provide in a hair clipper or similar device, an improved and. more eiiicient construction and assembly of the several operating instrumentalities of the device, which include the arrangement and mounting of the electro-magnet and permanentarmature vibrator in the casing, the arrangement and I support of a vibration absorbing element for the .2 clipper, and the specific arrangement and form of the devices for holding together'and attaching the parts of the blade assembly to the clipper casing.

The hair clipper provided in accordance with the present invention, comprises a casing which is conventionally. long and narrow, with a cutter blade assembly disposed at one end thereof. An E-shaped electro-magnet is mounted within the rear or butt end of the casing, and an armature vibrator and vibration absorbing element are disposed in the middle portion of the casing between the blade assembly and electro-magnet. In the preferred form of the invention illustrated; the electro-magnet is supported with the pole faces thereof extending transversely of the casing, and the armature vibrator is mounted on parallel supporting spring arms for movement bodily transversely of the casing. The armature so arranged, vibrates transversely of and clear of the pole faces of the electro-magnet regardless of the amplitude of movement imparted thereto.

In accordance with the invention, the armatnre vibrator of the motor assembly is a U-shaped magnet of fixed polarization which may take the form either of a permanent magnet or of an electromagnet with continuous direct current excitation, and the armature magnet is so disposed with relation to the pole faces of the E-shaped electro-magnet, that each successive shift of polarity otthe pole faces thereof induced by the successive phases :of the alternating current, will act in alternate directions upon the armature vibrator to effect one complete oscillation of the vibrator for each complete cycle of said alternating current or at the rate of 3600 vibrations per minute where a sixty cycle alternating current is employed.

- Further in accordance with the invention, and in orderto obtain a substantially better regulation of thevi-brator motor for maximum load and for such changes in voltages of the power supply current as may be encountered, the armature vibrator is tuned to a natural rate of vibration which is at least equal to or slightly in excess of the rate of vibration impressed there- .on, and the extreme amplitude of vibration thus induced is then controlled by the use of resilient bumper devices. In the preferred form of the invention illustrated, regulation of the amplitude of vibration of the armature vibrator is effected by an arrangement of the vibrator and a vibration absorbing element so that their centers of gravity are in substantial alignment with one another to ether thereby will be readily understood by one skilled in the art from the following description taken tion of tional view in side elevation taken on the line '6-5 of Fig. 4; Fig.

' and its supporting springs; -mentary plan view illustrating particularly the vibration absorbing element including the spring Fig. 9 is prises a casing ID to I of thecasing it which able cover member supplied to the ternating current power source through a cable 30 and a clamping screw 38 and with opposed stop surfaces thereon spaced to contact one another at extreme limits of movement of the vibrator in each direction. In the preferred form of the invention illustrated, rubber bumpers are employed to absorb the shock of contact of these parts at each limit of movement in opposite directions.

Further in accordance with the invention, a simple and effective holding and locking device is provided for detachably connecting the blade assembly to the body portion or casing of the clipper, and an otherwise inoperative spring clip is provided to prevent inadvertent falling apart of the elements of the blade assembly when disconnected from the body portion or casing of the clipper.

With the several objects in view as above noted, the several features of the invention consist also in the devices, combinations and arrangement of parts hereinafter described and claimed, which with the advantages to be obtained in connection with the accompanying drawings, in which Fig. 1 is a plan view of a clipper embodying the several features of the invention,

.the cover of the casin having been removed to .show underlying parts; Fig. 2 is a view in side elevation partly in section of the clipper as shown but with the cover in place; Fig. 3 is -a detail sectional view taken on the line 33 of in Fig. 1,

Fig. 1; Fig. 4 is a fragmentary plan view illustrating particularly the blade assembly and the latching device for attaching the same to the Fig. 5 is a side elevation partly in seethe parts shown in Fig. 4; Fig. 6 is a seccasing;

7 is a fragmentary plan view illustrating particularly the armature vibrator Fig. 8 is a fragarms by which it is attachedto the casing; and

As shown in the drawings, the clipper comwhich is secured a clipper blade assembly including a lower fixed blade member l2 and a cooperating vibratory blade member M. The several operating instrumentalities for imparting vibratory movement to the blade member M are mounted within the body is formed with a remov- IG for easy access to the opcrating parts of the clipper. An electro-magnet and armature vibrator-type of motor is provided for driving the vibratory blade member l4, which comprises an E-shaped electro-magnet I8 rigidly secured within the rear or butt end of the clipper casing by means of two clamping screws I9. The electro-magnet 58 consisting of a central pole 20 and two outer poles 2|, 22 is mounted with thepole faces thereof arranged in a plane extending transversely of the casing. Power is electro-magnet !8 from any al- 24 and a start and stop switch 26.

An armature vibrator is provided, which takes I the'form of a U-shaped permanent magnet 28,

and a flat spring driving member 30 which has formed thereon apair of driving lugs 32 for engagement with corresponding recesses 34 in the upper blade member a section taken on the line 99 of Fig. 1;

thus acts to damp out conveniently accomplished by 4 driver and U-shaped magnet to move as a. unit. The armature vibrator including the U-shaped magnet 28, and the driver plate are supported to move bodily toward one side and then to the other side of the casing on a pair of supporting

leaf springs

40, 42 which are rigidly connected to the legs of the U-shaped magnet 28 by means of blocks 44 and fasteners 46. At their forward ends the

springs

40, 42 are secured respectively to bosses 48, on the casing by means of clamping screws 52. It will be noted that the two legs of the U-shaped magnet 28 have secured to the ends thereof,

pole pieces

54, 56 which for the intermediate rest position of the armature vibrator shown in Fig. 1, substantially bridge the distance between the central pole 20 of the E-shaped magnet l8 and the outer poles 2|, 22 respectively. With the construction illustrated, the armature vibrator including specifically the

pole pieces

54, 56 are arranged to vibrate transversely clear of the pole faces of the electromagnet, so that no limitation is placed upon the amplitude of movement of the armature vibrator in either direction as a result of interference with the pole pieces.

Further in accordance with the present invention, a vibration absorbing element is provided in the form of a vertically extending I- shaped weighted member 64 which projects upwardly between the legs of the permanent magnet 28, and is formed at its lower end with two rearwardly extending arms 66 connected by means of a pair of leaf spring members 68, H1 to the

bosses

48, 50 on the casing I 0. The leaf springs 68, 10 on which the vibration absorbing element is arranged to vibrate, are mounted in parallel relation and directly beneath the supporting

springs

40, 42 for the armature vibrator, so that the vibration absorbing element is permitted to vibrate freely. in opposite phase from the armature vibrator. The vibration absorbing element is of the so-called dynamic type which is caused to vibrate 180 degrees out of phase with the armature vibrator by the vibrations which tend to be set up in the casing, and these vibrations in the casing. For tuning the vibration absorbing element to a natural frequency of vibration which will fully damp out the vibrations which tend to be set up by the operation of the armature vibrator, the weight of the I-shaped member 54 is adjusted by the removal of surplus metal means of a drill hole 12 in the under side of the member 64. The armaturevibrator and vibration absorbing element are so supported and arranged as to bring the centers of gravity of these parts into substantial alignment.

In accordance with the present invention, a novel and eflicient arrangement of the electromagnet and armature vibrator driving means in a hair clipper is provided to cause the vibrator and movable'blade to oscillate at the same frequency with the alternating input current employed to drive the clipper. Assuming the usual sixty cycle alternating current, the clipper will vibrate at 3600 cycles per minutes as compared with the 7200 vibrations normally produced by an electro-magnet and vibrator-type motor.

The arrangement of the motor driving con- 'nections here provided is such as to provide for clipper for causing the movable blade to oscillate at this relatively lower speed while maintaining a maximum power output for the clipper. With the pres ent construction, the relatively low rate of oscillation is produced through the cooperative action of the E-shaped electro-magnet it and the U- shaped armature magnet 28 which is fixedly polarized. Successive changes of polarization of the poles of the E-shaped magnet will act upon the fixedly polarized legs of the U-shaped armature magnet/28 to cause the armature vibrator to be oscillated in one direction with one phase of the input current, and to be oscillated in the other direction with the other phase of the input current. In order to obtain a maximum power output with this arrangement, the armature vibra-- tor including the supporting springs as, 42 is tuned to vibrate at or slightly in excess of the 7 rate of vibration impressed thereon by the alternating input current.

Further, in order to maintain an accurate phase relationship with a maximum power output over a predetermined range of loading of the clipper, resilient bumpers are employed to positively limit the amplitude of vibration of the armature vibrator. In, the illustrated form of the invention, the bumpers referred to, are mounted on the vibration absorbing element and consist of rubber bumpers '84, it which are held in recesses 18 in opposite sides of the upwardly extending I-shaped element lid to engage alternatively against the inner faces of the legs of the U-shaped armature magnet 23. The bumpers are spaced from the U-shaped magnet so that contact will take place only when the vibration absorbing element and the armature vibrator have reached predetermined limits of movement in op 'posite directions.

Further in accordance with the invention, to maintain at the highest possible eiiiciency the efiectiveness of the vibration absorbing element, and specifically to avoid the building up of a force couple as the result of the repeated contact of the armature vibrator and said vibration absorbing element, these parts are supported and arranged with their centers of gravity substantially in alignment, and the bumpers 74, it are located on this line of the centers of gravity so that substantially no twisting strains are set up either in the operating parts or casing. The arrangement" of the bumpers between the U- shaped armature magnet and the vibration absorbing element has the particular advantage that it entirely eliminates the twisting stresses which might otherwise be set up in the casing, and since the bumpers are supported separately from the casing, serves also to eliminate vibration which otherwise would inevitably be set up I by the repeated contacts of the vibrator and associated stop surfaces.

In the illustrated construction, the fixed blade 12 and vibratory blade l4 are constructed and arranged as a separate assembly which may be readily secured to or detached from the casing in as may be desired. As best shown in Figs. 4, 5 and 6, the bottom or fixed blade member I2 is provided on opposite sides thereof with two

countersunk holes

80,82 arranged to receive two

positioning pins

84, 86 which project from the under side of the clipper casing at an acute angle. The under or fixed blade member [2 is held firmly in position against the positioning pins by means of a spring-pressed latch plate 88 pivoted at the right side of the clipper casing on a pivot pin 90 to extend across the casing, and formed intermediate its length with a downwardly extending arm 92 which engages firmly against the head of a centrally located stop screw 94 on thestationary blade member 12. A leaf spring 96 rigidly secured by one of the clamping screws 52 is arranged for engagement against a hub 98 on the latch plate 88, so that the latch plate is held under tension tomaintain the fixed blade in operative position against the positioning :pins 84, 86 on the casing l0. An upwardly extendiing manually operable extension Hill formed at the further or left hand end of the latch plate provides a convenient means for the operator to move the latch against'the pressure of the spring 96 to permit the removal of the clipper blade assembly.

In the preferred construction shown, a spring clip llll is provided which is rigidly secured to the centrally located stop screw 94, is bent upwardly to pass through a central cutaway portion of the upper movable blade member 84, and has the end portion thereof extending into but not engaging with a slot 562 formed in the top face of the movable clipper blade i4, so that when the clipper blade assembly is disassociated from the casing and the upper blade is therefore disengaged from the spring driving plate 39, the upper blade will be held loosely in contact with the lower blade to prevent the disassociation and possible loss of one or both of these elements of the clipper blade assembly.

The operation of the clipper is briefly as follows: The successive shifts of polarity in the legs of the E-shaped electro-magnet l8 induced by the shifting phases of the alternating A. C. input current, causes the permanent magnet armature vibrator 28 supported on its

parallelsprings

40, 42 together with the movable blade l4 to be moved bodily first toward one side and then toward the other side of the casing, the rate of vibration being substantially at the frequency of the alternating current, or at the rate of 3600 vibrations per minute, when a sixty cycle A. C. current is employed. As previously pointed out, the armature vibrator including the

springs

40, 42, is tuned to have a natural frequency of vibration which is at least equal to or slightly above the frequency of vibration impressed on the armature by the input current, thus providing a condition in which the amplitude of vibration tends to build up to a maximum, and with a correspondingly high power output of the device. The operation of the clipper at current frequency instead of double the current frequency which is the more usual condition in clippers of this type, has the effect of substantially doubling the available cutting force of the device. Still further, the use of the rubber bumpers l4, 16 which act to positively limit the amplitude of vibration well within the natural limit of vibration of the system, has the eiiect of still further increasing the power out-put of the device, tending to minimize the effect of increasing load upon the vibratory movement of the movableblade, and acts to substantially improve the regulation of the device, in that it provides a substantial margin within which variations either of load or of voltage will not affect the operation of the device.

In the operation of the illustrated clipper, th vibration absorbing element comprising the weighted member 64 with the parallel support ing springs 68, it, operates in an extremely effective manner to damp out the vibrations which tend to be set up in the casing by the oscillatory movement of the armature, and also provides support for the rubber bumpers to absorb the shock of repeated contacts of the armature with the bumpers, so that this shock is not transmitted to the casing. Vibrations which tend to be set up in the casing by the vibratory movement of the armature and movable blade cause a 180 degree out-of-phase vibratory movement to be set up in the dynamic vibration absorbing element which damps out any vibration of the casing. The vibration absorbing element being supported in a manner similar to the manner of supporting the armature on parallel springs and from the same pivot block in the casing is well adapted to counterbalance with substantial accuracy the vibratory movement of the armature. A specific advantage of the construction illustrated, consists in the arrangement which permits both the armature and vibration absorbing element to oscillate on centers of gravity which are in substantial alignment. To further insure the quiet operation of the device, the rubber bumpers referred to, are arranged on the vibration eliminator to contact with the armature on this line of centers of gravity, thus to avoid the setting up of any torsional or twisting strains during the operation of the device.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is:

1. In a vibrator-type tool having a casing and a vibratory tool member supported from the casing, the combination of a motor comprising an electro-magnet and an armature vibrator connected to impart vibratory movement to the tool member, a vibration absorbing element supported from the casing and arranged to vibrate in opposition to the vibratory movement of said vibrator, and opposed stop surfaces on the vibrator and vibration absorbing member spaced to contact one another at extreme limits of movement of the vibrator in each direction.

2. In a vibrator type tool having a casing and a vibratory tool member supported from the casing, the combination of a motor comprising an electromagnet and an armature vibrator connected to impart vibratory movement to the tool member, said armature vibrator being tuned to substantially the rate of vibration impressed thereon, a vibration absorbing element supported A from the casing and arranged to vibrate in opposition to the vibratory movementof said vibrator, and opposed stop surfaces on the vibrator and vibration absorbing element spaced to contact one another at extreme limits of movement of the vibrator in each direction.

3. In a portable vibrator-type tool having a casing and a vibratory tool member supported from the casing, the combination or" a motor comprising an electro-magnet, an armature vibrator arranged to vibrate transversely clear of the magnet and connected to impart vibratory movement to the tool member, a vibration absorbing element spring-supported from the casing to vibrate in opposition to the vibratory movement of the vibrator, said tool member and armature vibrator being disposed with their centers of gravity substantially in alignment, and opposed stop surfaces on the vibrator and vibration absorbing member disposed substantially on said centers of gravity to contact one another at extreme limits of movement of the vibrator in each direction.

4. In a portable vibrator-type tool having a casing and a vibratory tool element supported from the casing, the combination of an electromagnet, an armature vibrator arranged to vibrate clear of the magnet and connected to impart vibratory movement to the tool element and including spring means acting upon the vibrator tuned substantially to the rate of vibration impressed upon the vibrator, a vibration absorbing element spring supported from the casing and tuned to vibrate in opposition to the vibratory movement of said vibrator, and resilient shock-absorbing bumpers disposed within the casing to limit the amplitude of vibration of said vibrator in each direction.

5. In a portable vibrator-type tool having a casing and a vibratory tool element supported from the casing, the combination of a vibrator motor including a vibrating member carried by the casing and connected to impart vibratory novements to the tool element, a vibration absorbing element supported from the casing to vibrate in opposition to the vibratory movement of the vibrating member and tool element, and further arranged to contact with the oppositely moving vibrator member at each limit of movement to limit the amplitude of the vibrations of said vibrator.

6. A claim in accordance with claim 4, in which yieidable buiier members are interposed between the vibration absorbing element and vibrator to limit the amplitude of the vibrations of said vibrator.

7. In a portable vibrator-type tool having a casing and a vibratory tool element supported from the casing, the combination of an electromagnet, an armature vibrator connected to impart vibratory movements to the tool element, spring means acting upon the vibrator tuned substantially to the rate of vibration impressed upon the vibrator, a vibration absorbing element supported within the casing to vibrate in oppositicn to the vibratory movement of the vibrator, said vibrator and vibration absorbing element being arranged to stop one another at opposite limits of movement to limit the amplitude of vibrations of the vibrator and tool element, and resilient bumpers interposed between the vibrator and vibration absorbing element.

8. In a portable vibrator-type tool having a casing and a vibratory tool element supported from the casing, the combination of an electromagnet, an armature vibrator connected to impart vibratory movement to the tool element, a vibration absorbing element mounted within the casing arranged to vibrate in opposition to the vibratory movement of said vibrator, and opposed stop surfaces on-the vibrator and vibration absorbing element spaced to contact one another at extreme limits of movement of the vibrator in each direction, said vibrator and element being so arranged and having the opposed stop surfaces thereon located substantially at the center of gravity of said vibrator and element respectively.

9. In a portable vibrator-type tool having a casing and a vibratory tool element supported from the casing, the combination of a vibrator motor including a pivotall supported vibrating member carried by the casing and connected to impart vibratory movements to the tool element, a vibration absorbing Weighted spring element supported from the casing and tuned to vibrate in opposition to the vibratory movement of the vi brating member and tool element, said vibrating member and element being constructed and arranged with their centers of gravity substantially in alignment, and stop surfaces formed on said centers of gravity for engagement at opposite limits of movement of said vibrating member and element to limit the amplitude of vibrations of said vibrating member.

10. In a portable vibrator-type tool having a casing and a vibratory tool element supported from the casing, the combination or an electromagnet having pole faces, an armature vibrator pivotally supported to vibrate transversely clear of said pole faces for imparting vibratory movements to the tool element, a vibration absorbin Weighted spring element supported from the casing and tuned to vibrate in opposition to the vibratory movement of the vibrator, said vibrator and element having their centers of gravity substantially in alignment, and opposed stop surfaces substantially on the line of the centers of gravity of said vibrator and element for engagement with one another at opposite limits of movement of said vibrator and element.

11. In a portable vibrator-type tool having a casing and a vibratory tool element supported from the casing, thecombination of a vibrator motor comprising an E-shaped electro-magnet having the pole faces thereof disposed transversely of the casing, means for supplying current to the electro-magnet from an alternating current source, an armature vibrato-r comprising a fixedly polarized armature magnet arranged for movement transversely clear of the electro-magnet pole faces and so disposed whereby successive shifts of polarity of the electro-magnet induced by the alternating phases of the alternating current will act in alternate directions upon the armature magnet vibrator to effect one complete oscillation of the vibrator for each complete cycle of said alternating current, supporting means for the armature vibrator tuned substantially to the rate of vibration impressed thereon, a vibration absorbing element supported from the casing to vibrate in opposition to the vibratory movement of the vibrator, and opposed stop surfaces on the vibrator and vibration absorbing member to contact one another at the extreme limits of movement of the vibrator in each direction.

12. In a portable vibrator type tool having a casing and a vibrating tool element supported from the casing, the combination of an E-shaped electromagnet having the pole faces thereof disposed transversely of the casing, an armature vibrator comprising a U-shaped fixedly polarized magnet arranged for transverse movementclear of said pole faces, said U-shaped magnet being secured to move as a unit with the vibrating tool element, a pair of supporting spring arms extending parallel to the armature vibrator connected witha portion of the U-shaped armature magnet adjacent the electromagnet and to a portion of the casing away from the electromagnet along the length of the vibrating tool element, whereby the armature vibrator and vibrating tool element are moved bodily toward one side and then toward the other side transversely of the casing, and a vibration absorbing element comprising a weighted member disposed between the legs of the U- shaped armature magnet, and a pair of parallel supporting springs for said member supported from the same portion of the casing with said armature supporting springs.

13. In a portable vibrator type tool having a casing and a vibrating tool element supported from the casing, the combination of an E-shaped electromagnet having the pole faces thereof disposed transversely of the casing, an armature vibrator comprising a U-shaped fixedly polarized magnet arranged for transverse movement clear of said pole faces, said U-shaped magnet being secured to move as a unit with the vibrating tool element, a pair of supporting spring arms extending parallel to the armature vibrator connected with a portion of the U-shaped armature magnet adjacent the electromagnet and to a portion of the casing away from the electromagnet along the length of the vibrating tool element, whereby the U-shaped magnet and vibrating tool element are moved bodily toward one side and then toward the other side transversely of the casing, a vibration absorbing element comprising a weighted member disposed between the legs of said U-shaped magnet, a pair of supporting spring arms therefor disposed parallel to said armature supporting spring arms and connected with said portion of the casing, and opposed stop surfaces disposed substantially at the centers of gravity on said member and said armature magnet including shock absorbing bumpers to limit movement of the U-shaped magnet and vibrating tool element in each direction.

GEORGE N. LEVESQUE.

REFERENCES CITED UNITED V STATES PATENTS Number Name Date 7 Re. 19,816 Wurzbach et a1. Jan. 7, 1936 1,887,968 Tompkins Nov. 15, 1932 1,895,292 Miner Jan. 24, 1933 2,098,180 Dilks Nov. 2, 1937 2,168,642 Andis Aug. 8, 1939 2,304,525 Andis Dec. 8, 1942 2,434,671 Murphy Jan. 20, 1948 FOREIGN PATENTS Number Country Date 479,652 Germany July 20, 1929