Abstract:
A chiropractic adjustor apparatus having an electromagnetic drive mechanism connected to an actuating means which causes a shaft to reciprocate. The reciprocating shaft is used to apply pressure or force directly to the spinal vertebrae of a body. The improvements of this device include a variable-controlled switch to enable the user to change the frequency of the reciprocation; a thermal cut-off switch that automatically turns off the power to the electromagnetic drive mechanism so that the device will stop reciprocating; and a suite of structures that work together to resist rotation when the device is in use.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part (CiP) of U.S. application Ser. No. 09/749,023 filed Dec. 26, 2000, now U.S. Pat. No. 6,537,236. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to a chiropractic adjustor apparatus used to apply vibratory energy or force to a patient and, more particularly, relates to a chiropractic adjustor apparatus having an improved ability to resist overheating and rotation during use. 
     BACKGROUND OF THE INVENTION 
     Chiropractic adjustments of the spinal vertebrae of a body involve the application of pressure or force in a known manner directly to the body by the hands of a chiropractor or by a chiropractic adjustor apparatus. Examples of such chiropractic adjustor apparatuses found in the prior patent art are those disclosed in U.S. Pat. No. 4,716,890 to Bichel and U.S. Pat. No. 4,841,955 to Evans et al. 
     Another example of a prior art chiropractic adjustor apparatus is the one illustrated in FIG.  1 . The apparatus of FIG. 1 includes a housing, a handle on the housing, a trigger reciprocally mounted to the handle, an electronic control module provided in the handle and activated by depression and release of the trigger, an elongated force-transmitting shaft reciprocally mounted through the housing. An electromagnetic drive mechanism is disposed in the interior cavity of the housing and connected electrically to an electronic module. It is operable by the actuation of the trigger and the return action of a compressible spring near the rear portion of the housing, causing the shaft to transmit vibratory energy to the human body. 
     The electromagnetic drive mechanism includes a spool with electrical windings stationarily supported in the interior cavity of the housing and a stator mounted on the shaft and disposed within a bore of the spool in an electromagnetically coupled relationship with the electrical windings about the spool. Depressing the trigger activates the electrical control module to apply predetermined pulses to the electrical windings so as to actuate the stator and thus the shaft into repetitive reciprocal vibratory type of movement along a longitudinal axis of the shaft and relative to the housing. However, the prior art provides only a single frequency of the reciprocation. This prevents the treatments from being customized to the patient&#39;s need. It is desirable to provide variable frequencies for use with various treatment regimens. 
     The operation of the electromagnetic drive mechanism creates substantial heating of the electrical windings which, in turn, heats the portions of the housing adjacent thereto. The buildup of heat must be dissipated from the housing in order to prevent overheating of the handle connected thereto and of the electronic control module disposed in the handle. Unsatisfactory dissipation of the heat would make it uncomfortable and difficult for the operator to hold onto the handle for an extended period of time and have the potential to cause a malfunction of the electronic control module. A plurality of passages are provided through the rear portion of the housing to facilitate passage and dissipation of heat from the drive mechanism and housing. It is desirable to provide a thermal cut-off switch to prevent the device from overheating and causing damage to the device. 
     During operation, the prior art devices tend to rotate, or twist, out of the user&#39;s grip, as a result of the rotational components of the force exerted on the shaft by the electromagnetic drive mechanism, causing the operator to exert much effort in holding the device substantially perpendicular to the patient&#39;s vertebrae. It is desirable to provide means to resist such rotation so that the device can be held in the proper position along the patient&#39;s spine. 
     Consequently, a need exists for an innovation that will provide a configuration that will overcome the aforementioned problems of the prior art. Therefore, it is an object of this invention to provide a device that provides a variable frequency of reciprocation. It is another object of this invention to provide a device with an improved ability to resist overheating. It is another object of this invention to provide a device that resists rotation during use. 
     SUMMARY OF THE INVENTION 
     The present invention is a chiropractic adjustor apparatus having an electromagnetic drive mechanism connected to an actuating means which causes a shaft to reciprocate. The reciprocating shaft is used to apply pressure or force directly to the spinal vertebrae of a body. The improvements of this device include a variable-controlled switch to enable the user to change the frequency of the reciprocation; a thermal cut-off switch that automatically turns off the power to the electromagnetic drive mechanism; easily interchangeable force-transmitting elements; and a suite of structures that work together to resist rotation when the device is in use. 
     These and other features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following detailed description, reference will be made to the attached drawings in which: 
     FIG. 1 is a side elevational view of the prior art chiropractic adjustor apparatus that has been described in detail in the background section of this application. 
     FIG. 1A is an end elevational view as seen along line  1 A— 1 A of FIG.  1 . 
     FIG. 2 is a perspective view of one embodiment of the present invention showing different heads that can be used with the chiropractor adjustor apparatus. 
     FIG. 3 is an exploded perspective view of the apparatus of FIG.  2 . 
     FIG. 4 is a longitudinal sectional view of the apparatus of FIG.  2 . 
     FIG. 5 is an enlarged cross sectional view of the apparatus taken along line  5 — 5  of FIG.  4 . 
     FIG. 6 is a perspective view of a second embodiment of the present invention showing the variable frequency controller and a force transmitting element showing attachment with a spring latch. 
     FIG. 7 is a perspective view of the thermal cut-off switch attached to the electromagnetic drive mechanism. 
     FIG. 8 is a perspective view of the slotted bushing. 
     FIG. 9 is a perspective view of a force transmitting element showing a spring latch. 
     FIG. 10 is a cross-sectional view line  10 — 10  of FIG.  9 . 
     FIG. 11 is an end elevational view of a force transmitting element showing the hexagonal aperture for receiving the hex head on the shaft. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and particularly to FIGS. 2 to  11 , there is illustrated a chiropractic adjustor apparatus of the present invention, generally designated  40 . The apparatus  40  of the present invention basically includes a housing  42 , an elongated force-transmitting shaft  44 , an electromagnetic drive mechanism  46 , an actuating arrangement  48  and a gripping means in the form of a handle  50 . 
     The housing  42  of the apparatus  40  has a middle portion  52  defining a central interior cavity  54  and a pair of opposite (or front and rear) end portions  56 ,  58  merging from the middle portion  52 . The opposite end portions  56 ,  58  are substantially mirror images of one another and oriented substantially the reverse of one another relative to the middle portion  52  so as to extend in opposite directions from the interior cavity  54 . The opposite end portions  56 ,  58  are spaced apart from one another by the middle portion  52  and together with the middle portion  52  are coaxially aligned with one another about a longitudinal axis  60  of the housing  42 . Each of the opposite end portions  56 ,  58  has a central opening  62 ,  64  and a plurality of axially extending passages  66 ,  68 . The central openings  62 ,  64  of the respective opposite, or front and rear, end portions  56 ,  58  are aligned with one another and extending parallel with the longitudinal axis  60  of the housing  42 . The passages  66 ,  68  of each plurality thereof are circumferentially spaced apart from one another about and radially arranged outwardly from the longitudinal axis  60  of the housing  42 . Such passages  66 ,  68  are adapted to enhance heat dissipation from the housing  42 . The middle portion  52  of the housing  42  is substantially cylindrical in shape and the opposite (or front and rear) end portions  56 ,  58  of the housing  42  are reversely-oriented and substantially conical in shape. More particularly, the housing  42  is formed by a pair of substantially identical (front and rear) housing parts  42 A,  42 B are arranged in a mirror-image back-to-back relationship and in a reverse orientation with one another so as to define together the central interior cavity  54 . The housing parts  42 A,  42 B are assembled together by a first pair of screws  70  which fixedly attach the handle  50  on a lower side  52 A of the housing  52  via alignable holes  72 ,  74  defined in the handle  50  and the lower side  52 A of the middle portion  52  of the housing  42  such that the handle  50  underlies and bridges the housing parts  42 A,  42 B and by a second pair of screws  76  which fixedly attach a curved plate  78  on an upper side  52 B of the middle portion  52  of the housing  42  via alignable holes  80 ,  82  defined in the plate  78  and the upper side  52 B of the middle portion  52  of the housing  42  such that the curved plate  78  overlies and bridges the housing parts  42 A,  42 B. The handle  50  also has an interior compartment  84 . 
     The elongated force-transmitting shaft  44  extends through the electromagnetic drive mechanism  46 , through the middle portion  52  and interior cavity  54  of the housing  42 , and through the central openings  62 ,  64  in the opposite (front and rear) end portions  56 ,  58  of the housing  42 . In such manner, the shaft  44  is reciprocally supported by the opposite end portions  56 ,  58  of the housing  42 , preferably in a substantially symmetrical relationship to the electromagnetic drive mechanism  46 . The shaft  44  defines a longitudinal axis  86  which extends coaxially along the longitudinal axis  60  of the housing  42 . More particularly, the shaft  44  has a middle portion  44 A disposed in the interior cavity  54  of the housing  42  and a pair of opposite (or forward and rearward) portions  44 B,  44 C extending in opposite directions from the interior cavity  54  and through and outwardly from the central openings  62 ,  64  of the opposite (or front and rear) end portions  56 ,  58  of the housing  42 . A pin  88  is mounted across the forward portion  44 B of the shaft  44  in a transverse relationship thereto. A sleeve  90  extends about and along the forward portion  44 B of the shaft  44  and has a longitudinal slot  92  receiving an end  88 A of the pin  88  such that the shaft  44  can undergo longitudinal movement through the sleeve  90  along the longitudinal axes  60 ,  84  of the housing  42  and shaft  44  but not undergo rotation about the axes  60 ,  84  and relative to the sleeve  90  and thus to the housing  42 . 
     The electromagnetic drive mechanism  46  is mounted in the central interior cavity  54  of the housing  42 . The drive mechanism  46  includes a stator  94 , a spool  96  and a series of electrical windings  98  disposed about the spool  96 . The spool  96  is stationarily supported by the housing  42  in the central interior cavity  54  of the housing  42  at the cylindrical middle portion  52  thereof. The spool  96  has a central bore  100  defined therethrough aligned with the central openings  62 ,  64  at the opposite (or front and rear) end portions  56 ,  58  of the housing  42 . The stator  94  is fixedly mounted on the shaft  44  about the middle portion  52  thereof and extends through the central bore  100  of the spool  96  in an electromagnetically coupled relationship with the electrical windings  98  about the spool  96  whenever an electrical current is moving through the windings  98 . 
     The actuating arrangement  48  is mounted to the handle  50 , is electrically connected to the electrical windings  98  of the electromagnetic drive mechanism  46 , and is operable to actuate the drive mechanism  46  to cause repetitive reciprocal vibratory movement of the shaft  44  along its longitudinal axis  86  relative to the housing  42 . The actuating arrangement  48  includes a trigger  102  reciprocally mounted to the handle  50  at a front upper location thereon immediately below the front end portion  56  of the housing  42 . The trigger  102  extends from the exterior of the handle  50  into the interior compartment  84  of the handle  50 . The actuating arrangement  48  also includes an electronic control module  104  provided in the interior compartment  84  of the handle  50  and an electrical power supply cable  106  connected to the module  104  through the bottom end  50 A of the handle  50 . Conductive wires  106  extending through passageways  50 B,  50 C in the handle  50  interconnect the trigger  102 , module  104  and electrical windings  98  on the spool  96  so as to form an electrical circuit therebetween. The trigger  102  is an electrical switch biased to normally assume an extended position in which the electrical circuit is maintained in a non-conductive or broken condition. The electrical circuit is closed and thus the module  104  is activated and the electrical windings  98  are energized by depressing the trigger  102 . When the trigger  102  is depressed, the electronic control module  104  is activated to apply predetermined pulses to the electrical windings  98  so as to actuate the stator  94  and thus the shaft  44  into repetitive reciprocal vibratory type of movement relative to the housing  42 . 
     The force applied by the elongated shaft  44  can be adjusted by the incorporation in the apparatus  40  of an arrangement in the form of a knob  108  disposed on a rear end  44 D of the shaft  44  and first and second springs  110 ,  112  disposed about the rearward portion  44 C of the shaft  44  respectively interiorly between the stator  94  and rear end  42 A of the housing  42  and exteriorly between the knob  108  and rear end  42 A of the housing  42 . Front and rear plugs  114 ,  116  are fixedly secured by screws  118 ,  120  in the front and rear central openings  62 ,  64  in the front and rear end portions  56 ,  58 . The front plug  114  provides a front stop which is abutted by the pin  88 . The rear plug  116  has an internal shoulder  116 A having opposite sides against which the first and second springs  110 ,  112  respectively abut. The knob  108  is threadable about the rear end  44 D of the shaft  44  toward and away from the rear end  42 A of the housing  42  such that by turning the knob  108  the return force imposed by the springs  110 ,  112  on the stator  94  and shaft  44  can be increased or decreased to thereby adjust the amount vibratory force applied to the human body at the front end of the shaft  44 . 
     Also, a plurality of force transmitting elements  122  of different configurations are adapted to be fitted to a hex shaped segment  124  of the front end  44 E of the shaft  44  and placed against a part of the human body to be treated. Other polygonal shapes may be used, particularly to resist rotation, as explained below. The different configurations of the elements  22  allow for the application of force in different ways to the human body. The adjustor apparatus  40  has a mode of operation similar to that of a jack hammer or the like. In the case of the apparatus  40 , vibratory impacts are transmitted at the front end  44 E of the shaft  44  by the selected one of the force transmitting elements  122  when it is placed against the desired part of the human body. 
     The force transmitting elements can be made to be easily interchangeable using a spring-latch. The force transmitting element with a spring-latch, referred to hereinafter generally as the spring-latch head  210 , is illustrated in FIGS. 6,  9  and  10 . Referring now to FIGS. 9 and 10, an aperture  212  is formed in the neck  211  of the spring-latch head  210  for receiving a tongue  213  of a spring-latch  214 . The spring-latch  214  is preferably attached to the neck  211  with a screw, but may also be attached with solder, adhesive, or other means. The tongue  213  is normally biased downward into the aperture  212 . To latch the spring-latch head  210  in place, the front-end of the shaft  44  is inserted into the neck  211  of the spring-latch head  210  until the tongue  213  is forced up and over the front end of the shaft and snaps into the groove  215  formed in the shaft for receiving the tongue  213 . Alternatively, a flange  216  may be used instead of the groove  215 , as shown in FIG. 3, in which case the tongue is forced up and over the front end of the shaft  44  and snaps into place behind the flange  216 . To unlatch the spring-latch head  210  for easy interchangeability, the end of the spring-latch  214  is depressed, forcing the tongue  213  up enough for the groove (or flange) to bypass the tongue  213  as the shaft  44  is withdrawn from the neck  211 . 
     Referring now to FIG. 6, a second embodiment of the present invention utilizes a variable frequency controller  201  attached to the handle  50  and electrically connected to the electronic control module  104  provided in the interior compartment  84  of the handle  50 . The variable frequency controller  201  can be used to adjust the current applied to the electrical windings  98  in pulses of various periods so as to actuate the stator  94  and thus the shaft  44  into repetitive reciprocal vibratory type of movement relative to the housing  42  in varying frequencies. Variable frequency controllers can be electromechanical or electronic, as are known in the art. 
     During use the device can generate substantial heat due to the heating of the electrical windings which, in turn, heat the portions of the housing. FIG. 7 illustrates a thermal cut-off switch  202  which is designed to cut-off power to the electrical windings  98  when the switch  202  reaches a given temperature. The thermal cut-off switch is preferably a bi-metal switch that forms an open in the circuitry when the temperature reaches 135° C. For optimal temperature sensitivity, the thermal cut-off switch  202  is preferably attached directly to the greatest source of heat generation, the electrical windings  98 . The thermal cut-off switch  202  is preferably applied with room-temperature vulcanizing silicone rubber, known in the art as RTV silicone rubber, but any other means of attachment that secures the switch and that can withstand device temperatures will suffice. 
     FIGS. 6,  8 ,  9 ,  10  and  11  illustrate a suite of structures that work together to resist rotation when the device is in use. Two points of rotation must be controlled: the rotation of the handle  50  relative to the shaft  44 , and the rotation of the shaft  44  relative to the force-transmitting elements. To prevent rotation between the handle  50  and the shaft  44 , a slotted bushing  217  (shown in FIG. 8) is used in place of front plug  114  or rear plug  116  (shown in FIG. 3) and is secured by screws  118  in the front central opening  62  in the front portion  56  of the housing  42 . Pin  88  extends through the slot and prevents the slotted bushing  217 —and therefore the attached housing—from rotating relative to the shaft  44 . To prevent rotation between shaft  44  and the force-transmitting element  122  and  210 , the shaft  44  utilizes a hex-shaped segment  124  of the front end  44 E of the shaft  44  which fits snugly in a mated, hex-shaped aperture  218  in the neck  211  of the force-transmitting element. The mated hex-shaped shaft and aperture prevent the prevents the rotation of the shaft  44  relative to the force-transmitting elements  122  and  210 . While hex-shaped is preferred, other polygonal-shaped apertures and mated segments that prevent the shaft from rotating within the aperture in the neck are acceptable. 
     It is thought that the present invention and its advantages will be understood from the foregoing description and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely preferred or exemplary embodiment thereof.