Abstract:
A portable rescue tool that is powered by an electric motor. The electric motor has a drive output shaft that transfers rotational power to an angle rotary gearbox. The angle rotary gearbox has an output shaft that is oriented about 90 degrees from the rotational axis of the motor output shaft and is geared so as to increase the torque and reduce the speed of the rotational power. The angle rotary gearbox provides a reduced speed, high torque output at an output shaft that is delivered by a single chain drive to a main rotary actuator where two actuator arms are controlled to move away from each other and toward each other in the operation of the rescue tool. The portable rescue tool is designed to be of a low weight and enhanced cooling properties as present rescue tools.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a device that can be used as a rescue tool by providing a spreading or cutting motion under high loads and, more particularly, to a portable rescue tool to carry out an emergency rescue that is lighter and more efficient than prior rescue tools 
       BACKGROUND OF THE INVENTION 
       [0002]    Rescue tools know as “Jaws of Life” type devices are specialized tools used by various rescue personnel such as police, firemen and paramedics generally for the purpose of extricating accident victims from vehicles whose exits have been rendered inoperative. These tools require spreading and closing forces for opening or ripping apart inoperable doors or for cutting through relatively thick metal layers. Pushing or pulling forces of 7,000 to 15,000 pounds at the tips are considered to be normal for the proper operation of such tools. 
         [0003]    A rescue tool of the present type is shown and described in U.S. Pat. No. 5,544,862 and U.S. Pat. No. 5,520,064 of Hickerson. In those patents, there can be seen a rescue tool that is battery powered and which is capable of high torque spreading and cutting motion of its jaws. While very useful and an improvement in its time, the rescue tool of those patents can be improved upon by reducing its weight to make the device easier to handle and by increasing its efficiency as to heat dissipation so as to lengthen the life of the motor. 
         [0004]    Accordingly, it would be advantageous to have a portable rescue tool that can carry out the functions of the rescue tools described in the aforementioned U.S. patents but which has increased efficiency, lower weight, is less expensive to manufacture and has improved heat dissipation. 
       SUMMARY OF THE INVENTION 
       [0005]    Now, in accordance with the present invention, there is provided a portable rescue tool that is powered by an electric motor. The electric motor has a drive output shaft that transfers rotational power to an angle rotary gearbox. The angle rotary gear box has an output shaft that is oriented about 90 degrees from the rotational axis of the motor output shaft and is geared so as to increase the torque and reduce the speed of the rotational power. 
         [0006]    That high torque is then transmitted by a single belt drive to a main rotary actuator to drive a pair of actuators having actuator arms that can be moved by the main rotary actuator so as to move away from and toward each other. The single belt drive reduces the weight of the overall portable rescue tool as well as provides a positive sprocketed drive between the angle rotary gear box and the main rotary actuator. 
         [0007]    In the exemplary embodiment, there is a brake assembly that directly contacts and provides a braking force to the motor shaft where the braking is the most effective. The braking assembly brakes the motor shaft when the power to the motor is terminated and allows the motor shaft to rotate freely when the motor is being energized. 
         [0008]    The portable rescue tool is readily manipulated by the user by providing a rubber grip located just adjacent to the proximal end of the motor housing and a handle bar that is angled slightly forwardly toward the working end of the portable rescue tool so that the user can have a firm, balanced hold on the portable rescue tool and can manipulate the portable rescue tool to carry out the desired operation. 
         [0009]    In the exemplary embodiment, the main rotary actuator is rotatably positioned in the portable rescue tool between an upper and lower plate and there is a clutch mechanism that allows the user to loosen and tighten a threaded knob to allow the entire main rotary actuator to rotate in the portable rescue tool or be prevented from rotation. Again, the components of the clutch as well as the assembly thereof are designed to reduce the weight of the portable rescue tool to make it easier for the user to manipulate the portable rescue tool in carrying out its function. 
         [0010]    Other features of the present portable rescue tool will become more apparent in light of the following detailed description of a preferred embodiment thereof and as illustrated in the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is an exploded view of an exemplary embodiment of the portable rescue tool of the present invention; 
           [0012]      FIG. 2  is an exploded view of the power subassembly used with the portable rescue tool of the present invention; 
           [0013]      FIG. 3  is a side cross sectional view of the portable rescue tool of  FIG. 1  taken along the line  3 - 3  of  FIG. 2   
           [0014]      FIG. 4  is a perspective view of the portable rescue tool of  FIG. 1 ; and 
           [0015]      FIG. 5  is a perspective view, partially broken away, showing another of the components of the present portable rescue tool. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Referring now to  FIG. 1 , there is shown an exploded view of the portable rescue tool  10  constructed in accordance with the present invention. As can be seen, the portable rescue tool  10  basically comprises a motor  12 , an angle rotary gearbox  14  and a main rotary actuator  16 . As can be seen, the motor  12  is contained with a motor housing  18  and a housing end cap  20  covers the proximal end  22  of the motor housing  18  and can be secured thereto by screws. 
         [0017]    An electrical cable  24  passes through the housing end cap  20  to supply election energy to the motor  12 . The electrical cable  24  also passes through a rubber grip  25  that can be gripped by the user in order to carry out the manipulation of the portable rescue tool  10 . 
         [0018]    The source of the electrical power can be a battery, not shown, and may be a variety of voltages, however, in the exemplary embodiment, the motor  12  is a 12 volt D.C. motor to be compatible with automobile or truck batteries. 
         [0019]    In the embodiment of  FIG. 1 , the motor  12  has pins  26  (only one of which is shown in  FIG. 1 ) that enter into slots  28  in the motor housing  18  and covers  30  can be secured to the motor housing  18  by means such as screws  32  to cover the slots  28 . 
         [0020]    At the distal end  34  of the motor housing  18 , the angle rotary gearbox  14  has an output shaft  36  emerging therefrom and, as will be later explained, the rotational axis of the output shaft  36  is generally at a right angle with respect to the longitudinal rotational axis of the motor  12 . A sprocket  38  is located at the free end of the output shaft  36 . 
         [0021]    A handle  40  is affixed to the external circular motor housing  18 . The handle  40  has an internal circular flange  42  that conforms to, and is affixed to, the exterior circular configuration of the motor housing  18  and has an external circular handle bar  44  that can be gripped by the user. When assembled to the motor housing  18 , the handle bar  44  is tilted slightly forwardly for the convenient gripping and manipulation by the user. 
         [0022]    As such, the user can readily manipulate the portable rescue tool  10  by grasping the circular handle bar  44  with one hand and the rubber grip  25  with the other hand and move the portable rescue tool  10  to the desired orientation for its desired use. 
         [0023]    As also can be seen in  FIG. 1 , the main rotary actuator  16  is affixed to the motor housing  16  by means of an upper plate  46  and a lower plate  48  with the main rotary actuator  16  sandwiched therebetween. At the lower end of the main rotary actuator  16 , there is an input shaft  50  that is rotatable to operate the main rotary actuator  16 . A sprocket  52  is affixed to the free end of the input shaft  50  and a drive coupling  54  couples the output shaft  36  of the angle rotary gearbox  14  to the input shaft  50  of the main rotary actuator  16 . 
         [0024]    In the exemplary embodiment the drive coupling  54  can be a single chain belt  56  that connects between the sprocket  38  on the output shaft  36  of the angle rotary gearbox  14  and the larger sprocket  52  at the free end of the input shaft  50  of the main rotary actuator  16 . 
         [0025]    One of the sprocket  38  on the output shaft  36  or the larger sprocket  52  on the input shaft  50  of the main rotary actuator  16  may include a slip mechanism that is commercially available and one supplier is Martin Sprocket &amp; Gear, Inc. of Arlington, Tex. The mechanism is a torque limiting clutch where a driven member slips when a torque overload is present. Typically, the activation of the torque limiting clutch makes a clicking sound when operational and thus the user is alerted that the torque overload is present and the mechanism is effectively limiting the torque. 
         [0026]    A gearbox retainer  58  is also included to strengthen the connection between the lower plate  48  and the lower end of the angle rotary gearbox  14  and a bottom cover  60  encloses and protects the drive coupling  54 . 
         [0027]    The main rotating actuator  16  includes two rotating actuators  62 ,  64  that rotate with respect to each other either toward each other or away from each other depending on the rotational direction of the motor  12 . Each of the rotating actuators  62 ,  64  has two pairs of aligned connecting holes, that is, upper holes  66  and lower holes  68 . Only the upper and lower connecting holes  66 ,  68  on the rotating actuator  64  are shown in  FIG. 1 , however, similar holes are present on the other rotating actuator  62 . 
         [0028]    The purpose of the aligned upper and lower connection holes  66 ,  68  are to connect actuator arms (not shown in  FIG. 1 ), that are used to pry or cut material by selectively having the actuator arms close towards each other or move away from each other in the normal operation of a portable rescue tool. 
         [0029]    Atop of the main rotating actuator  16  is a clutch mechanism  70  that controls the rotational movement of the main rotating actuator  16  with respect to the upper and lower plates  46 ,  48 , that is, the clutch mechanism  70  either allows the main rotating actuator  16  to rotate within the upper and lower plates  46 ,  48  or prevents that rotational movement. 
         [0030]    The clutch mechanism  70  is comprised of a relatively few components and is therefore light so as to enhance the maneuverability of the portable rescue tool  10  and allows the main rotary actuator  16  to rotate with respect to the fixed upper and lower plates  46 ,  48 . As can be seen, the clutch mechanism, comprises a clutch plate  72  that is non-rotatably affixed to the main rotary actuator  16  by means, such as tabs  74  that extend outwardly from the clutch plate  72  and which engage slots  76  formed on the upper surface of the main rotary actuator  16 . 
         [0031]    A clutch housing  78  is positioned atop of the upper plate  46  and can be firmly affixed thereto by screws or the like such that the clutch housing  78  does not move with respect to the upper plate  46 . A clutch material (not shown) is provided on the inner, downward surface of the clutch housing  78  and a screw  80  is centrally located and passes though the clutch plate  72  and extends upwardly through the clutch housing  78  where it is captured by a threaded knob  82 . Intermediate the clutch plate  72  and the clutch housing  78  is a friction disc  84 . 
         [0032]    Accordingly, to operate the clutch mechanism  70 , the threaded knob  82  can be rotated by the user so as to tighten the clutch plate  72  against the clutch housing  78  such that the friction therebetween prevents the clutch plate  72  from rotating and it becomes fixed with respect to the clutch housing  78 . Since the clutch plate  72  is keyed to the main rotary actuator  16  through the tabs  74  and slots  76 , the main rotary actuator  16  is prevented from rotating with respect to the upper and lower plates  46 ,  48 . 
         [0033]    If the user wants to move the rotational position of the main rotary actuator  16 , the threaded knob  82  is simply unscrewed from the screw  80 , thereby releasing the clutch plate  72  and allowing the main rotary actuator  16  be rotated to the desired orientation and the threaded knob  82  again tightened to retain the main rotary actuator  16  in the desired position. 
         [0034]    As such, the threaded knob  82  can be employed by the user to allow the rotational movement of the main rotating actuator  16 . Thus, the clutch mechanism  70  locks the position of the main rotating actuator  16  in a positive manner, requiring relatively few parts, thereby reducing the overall weight and allowing the main rotating mechanism  16  to rotate in both directions. 
         [0035]    Turning then to  FIG. 2 , there is an exploded view illustrating the power subassembly of the motor  12  and the angle rotary gearbox  14  within the motor housing  18 . As can be seen in  FIG. 2 , the motor  12  is located in the proximal end  22  of the motor housing  18  such that pins  26  enter into and are located within the slots  28 . A motor mount ring  92  is positioned distal to the motor  12  within the motor housing  18  to mount the motor  12  therein. As also shown, a motor shaft  94  extends outwardly from the motor  12  and connects the motor  12  to the angle rotary gear box  14 . The motor  12  and motor shaft  94  have a longitudinal axis of rotation. 
         [0036]    The angle rotary gear box  14  reduces the motor speed at a ratio of about 12:1 so that the characteristics of the output shaft  36  is one of low speed, high torque output. The motor shaft  94  can be seen to directly couple to the angle rotary gearbox  14 , thereby improving efficiency and reducing the weight of further coupling components. To also improve efficiency, it can also be seen that the angle rotary gearbox  14  directly receives the rotational movement of the motor  12  and changes the direction of the longitudinal axis of rotation of the motor shaft  94  to the rotational axis of the output shaft  36  of the angle rotary gearbox  14 . In the exemplary embodiment, that angle is about 90 degrees. 
         [0037]    There is also an electrically powered brake  96  that surrounds the motor shaft  94  and is held therein by means of a mount  98  that mounts the brake  96  as well as the angle rotary gearbox  14 . The brake  96  is electrically powered and is biased to its locked position preventing the motor shaft  94  from rotating, however, when power is applied to the brake  96 , and also the motor  12 , the brake  96  is released and the motor shaft  94  is free to rotate. 
         [0038]    Thus, the subassembly of the motor  12  and angle rotary gearbox  14  is a compact structure, readily assembled and removable from the other components of the portable rescue tool  10  and includes a minimum of components so as to minimize the weight to facilitate the manipulation and use of the portable rescue tool  10  by a user. The motor  12  is directly coupled to the angle rotary gearbox  14  and the angle rotary gearbox  14  delivers the high torque rotational energy. The brake  96  is located directly on the motor shaft  94  since less braking is needed at the motor shaft  94  than at other locations. 
         [0039]    Turning then to  FIG. 3 , there is a side cross sectional view of the portable rescue tool  10 . In  FIG. 3 , there can be seen the overall portable rescue tool  10  and illustrating the position of the motor  12  that has a longitudinal rotational axis that is generally horizontal as depicted in  FIG. 3  and the output shaft  36  of the angle rotary gearbox  14  has an axis of rotation that is generally at a right angle with respect to the axis of rotation of the motor  12 . 
         [0040]    A toggle switch  100  is provided in a location near the proximal end  22  of the motor housing  18  so as to be readily accessible to the user. By conventional wiring, the toggle switch  100  is connected between the electrical cable  24  and the motor  12  to energize and de-energize the motor  12  as well as to change the direction of rotation. 
         [0041]    Turning then to  FIG. 4 , taken along with  FIGS. 1-3 , there is shown a perspective view of the portable rescue tool  10  of the present invention. As such the angle rotary gearbox  14  is illustrated, as well as the motor housing  18  that encloses the motor  12 . The electrical cable  24  extends outwardly from the proximal end  22  of the motor housing  18  and includes the rubber grip  25  that is located just adjacent to the proximal end  22  of the motor housing  18  for gripping by the user. The user can also grip the handle bar  44  that, as can be seen, is angled away from the proximal end  22  of the motor housing  22  and thus toward the working end of the portable rescue tool  10 . 
         [0042]    Accordingly, both the rubber grip  25  and the handle bar  44  are conveniently located to enable the user to grip and manipulate the portable rescue tool  10 . 
         [0043]    As also can be seen in  FIG. 4 , the knob  82  is located atop of the main rotating actuator  16  for retaining and releasing the main rotating actuator  16  for rotational movement. 
         [0044]    In  FIG. 4 , there can also be seen, actuator arms  102 ,  104  that extend outwardly from the rotating actuators  62 ,  64 , respectively, such that the distal ends  106 ,  108  are moved by means of the rotating actuators  62 ,  64  to move the distal ends  106 ,  108  in opposite directions, that is, the distal ends  106 ,  108  can be forced together to carryout a cutting action or spread away from each other for creating a space between components of, for example, an automobile in gaining access thereto. 
         [0045]    Finally, in  FIG. 5 , there is a perspective view, partially cut away, of the main rotating actuator  16 . The main rotating actuator is commercially available and can be the same as that shown and described in the aforementioned U.S. Pat. No. 5,544,862 and U.S. Pat. No. 5,520,064 of Hickerson. 
         [0046]    Basically, the main rotating actuator  16  is comprised of a housing  110  and which is flanked by the rotating actuator  62 ,  64 . The input shaft  50  passes though the housing  110  and a main gear  112  is affixed thereto and rotates along with the input shaft  50 . Main gear  112  rotates a set of four follower gears  114  (only two of which are shown in  FIG. 5 ). The follower gears  114  are affixed to secondary shafts  116  having planetary gears  118  (again, there are two sets of planetary gears  118 ). 
         [0047]    The planetary gears  118  drive inner gears  120  internal of each of the rotating actuators  62 ,  64  to move those rotating actuators  62 ,  64  either toward each other or away from each other in the operation of the portable rescue tool  10 . 
         [0048]    While the present invention has been set forth in terms of a specific embodiment or embodiments, it will be understood that the present portable rescue tool herein disclosed may be modified or altered by those skilled in the art to other configurations. Accordingly, the invention is to be broadly construed and limited only by the scope and spirit of the claims appended hereto.