US 2428285 A
Description (OCR text may contain errors)
Sept. 30,1947. w, A, LEA 2,428,285
VIBRATION ISOLA'I'OR Filed March l] 1946 if/ 5? 46 d mum s /N VENTOR WALTER ALEXANDER LEA ATTORNEY Patented Sept. 30, 1947 UNITED STATES PATENT OFFICE VIBRATION ISOLATOR Walter Alexander Lea, Los Angeles, Calif., assignor to Frank H. Newton, Los Angeles, Calif.
Application March 11, 1946, Serial No. 653,544
The invention relates to a therapeutic vibrator and to a method of assembling the vibrator and has for an object to provide an improved and simplified type of motor and eccentric for producing the vibration as well as an improved full floating resilient support for the vibrating platform, and an improved method of assembling the full floating platform on its base.
For further details of the invention reference may be made to the drawing wherein Fig. 1 is a perspective view of a therapeutic vibrator according to the present invention, shown in an upsidedown position.
Fig. 2 is an enlarged sectional view of the motor of Fig. 1.
Fig. 3 is a view in elevation, partly in section and with parts broken away, showing one of the full floating spring suspensions of Fig. 1, Fig. 3 showing the device upsidedown.
Referring in detail to the drawings, the vibrator l of this invention comprises a base having thereon a full-floating vibratory platform 3, the device being shown upsidedown to illustrate the Working parts. The base 2 is in the form of a frame open at its top and bottom and having a plurality of spaced feet as indicated at 4 and 5, and the platform 3 which is adapted to support the patient, covers the top of the frame and has a depending flange 6 which extends over the vertical side wall 1 of the frame 2.
The platform 3 has a full floating resilient support on the base 2 and for this purpose there are provided a plurality of sets, here illustrated as four, spring suspensions, all alike, and one of which is indicated at 9 and shown enlarged in Fig. 3. As shown in Fig. 3, the platform 3 has an upright elongated lug Ill having a cross arm ll adjacent the bottom of side wall l and provided with a spring retaining notch i2 and the base 2 has an elongated upright lug [3 having a cross arm I 4 adjacent the top of side wall 1 and provided with a spring retaining notch l5. The lugs l and I3 are about as long as the height of the side wall I and are arranged inside of the side wall I. A helical coil spring l6 has its opposite ends engaged in the spring hangers or notches l2 and I5. The spring I is an upwardly pulling tension spring and tends to separate the platform 3 from the base 2. This tendency is counterbalanced by a parallel downwardly pulling helical tension spring ll having one end thereof connected in a spring hanger is in a short lug [9 on base 2, and its other end engaged in a spring hanger 20 in a short lug 2| on the platform 3.
The other four sets of spring suspensions like that shown in Fig. 3 are provided at substantially the four corners of the device I, as indicated at 9, 22, 23 and 24.
The tension of the springs l6 and ll is such that the weight of an average adult on platform 3 is not sufficient to force this platform to the top 25 of the base 2, while the patient by pushing down on the platform 3 can depress it enough to operate the switch 26 for the motor 2i. Switch 26 has a switch arm 28 which rocks in bearings 29 and 30 on the underside of the platform The switch arm 28 at its opposite ends has e2:- tensions 3| and 32 which bear against stops 33 and 34, respectively, on the opposite sides l of the frame 2. When the platform 3 is tilted by stepping on either side or pushed towards the base 2, the switch rod 28 is rocked to close switch 26 and connect a source of alternating current, not shown, to the motor 21.
Motor 21 is adapted to be operated by the standard 110 volt, cycle, single phase current, commonly used for house lighting circuits. Motor 21 is a self-starting induction type motor but is not of the ordinary type in that the stator 35 as shown in Fig. 2, is an internal member and is surrounded by a rotor 36 in the form of a cylindrical shell comprising an iron clad squirrel cage rotor.
The stator 35 has a central aperture 3i through which passes an axle 38 which is supported by and held stationary in the supports 38 and 4G. The stator 35 has a driven fit on or is suitably fixed to the stationary axle 38.
The stator 35 has four polar projections indicated at 4l-44. Around pole 42 is a winding 45 and around pole 44 is a field winding 46. These two windings 45, 46 magnetize the four poles. The field windings 45, 45 may be connected in series together and with the A. C. supply. Each pole ll-44 is provided with a shad ing coil short-circuited on itself, the shading coil for pole 4| being indicated at 41 and the other three poles 42-44 having a similarly positioned and arranged short-circuited shading coil. The shading coils like 41 remain short-circuited and their connections are not changed during the starting and running of the motor.
The rotor 21 is made up of a series of laminations of magnetic material having embedded therein a squirrel cage of which one of the bars is indicated at 48. The opposite ends of the bars like 48 are suitably short-circuited for example by a cast lead ring 49 between the end of the rotor 21 and each end plate 50, 5|. End plate 5| may have a series of fan blades 52 to ventilate the stator 35 and rotor 36 through the openings between the spaced feet such as 4 and 5 underneath the bottom of the imperforate surrounding side wall 1. End plate 50 carries a bearing 53 and end plate 5| has a similar bearing, not shown, to rotatably support the rotor 21 on the axle 38.
To cause the platform 3 to vibrate, there is attached to one end plate such as 50 an arcuate weight 54 which serves as an eccentric.
The amount of vibration may be adjusted by varying the radial position or amount of the weight 54. Its position may be varied by supporting it on one end by a pivot 55 and by securing the other end thereof to the end plate 50 by means of a screw 56 at a certain distance from the rotor axis, or by fastening screw 56 in another hole 51 which is at a different distance from the rotor axis.
Preferably the motor 2'! is positioned with its axis extending lengthwise of the middle of platform 3 with the eccentric 54 facing and adjacent the front end 58 of the platform.
In order to assemble the spring suspension, the base 2 is placed on top of the platform 3 as shown in Figs. 1 and 3, with the platform 3 farther away from base 2 than its normal floating position, and the springs like 16 are inserted through the open bottom of frame 2 one at a time and positioned in notches like I2 and I5, with springs [6 under little or no tension. Then the base and platform are placed in a jig and pressure is applied to urge platform 3 closer to base 2 than its normal floating position, thereby stretching springs IE to bring spring hangers l8 and 20 close enough together so that springs like IT can be inserted through the open bottom of base 2 and mounted with little or no tension on the hangers like I8 and 20. Then the jig and pressure are removed and the platform 3 floats on the four sets of springs like It and H, which then exert their normal opposed tensions. Springs like 16 are more powerful than the springs like 11, because the springs like IE not only must overcome the tension of springs like I! but also the weight of an adult person or whatever portion of his body is supported by the platform 3.
It will be apparent that various modifications may be made in the invention without departing from the spirit of the following claims.
1. A therapeutic vibrator comprising a vibratory platform, a base therefor comprising a frame open at the top and bottom and having a vertical side wall, a plurality of spaced base lugs extending upwardly from and inside of said side wall,
each of said base lugs having an upright portion having at one side thereof a (first) spring hanger adjacent the bottom of said base and having at the other side thereof a cross arm having a (second) spring hanger adjacent the top of said wall, said platform having depending therefrom a similar pair of lugs for each of said base lugs, one member of each of said pairs being short and having a (third). spring hanger above one of said first spring hangers, the other member of each of said pairs having an elongated pendant portion having a cross arm having a (fourth) spring hanger adjacent the bottom of said wall below one of said second spring hangers, a set of downwardly pulling tension springs each connected at one end to one of said first spring hangers and at its other end to its companion third spring hanger, and a set of upwardly pulling tension springs each connected at one end to one of said second spring hangers and at its other end to its companion fourth spring hanger.
2. A therapeutic device comprising a base having a surrounding side wall, said base having an open top and having a bottom having an enlarged opening therein, a vibratory platform covering said top, a full floating spring suspension for said platform inside of said side wall, said suspension comprising a. set of helical tension springs urging said platform to said base, and a second set of helical tension springs urging said platform away from said base, a group of short and long spring hangers on said base and a companion group of short and long spring hangers on said platform supporting said springs laterally spaced apart around said wall, with a short hanger of each group for a spring of said first set and a long hanger of each group for a spring of said second set, said opening in said base providing access to all of said springs.
3. A therapeutic device comprising a base frame having a surrounding side wall having an opening at the top and bottom thereof, a vibratory platform covering said top, and a full floating spring suspension for said platform inside of said side wall, said suspension comprising a plurality of pairs of tension springs connected to said base and to said platform in opposed relation.
WALTER ALEXANDER LEA.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 2,234,770 Meyer Apr. 11, 1941 1,845,941 Stevens et a1 Feb. 16, 1932 2,235,158 Krenzke Mar. 18, 1941 2,235,183 Wettlaufer Mar. 18, 1941 2,368,727 Robinson Feb. 6, 1945 653,906 Brown July 17, 1900