Abstract:
A device to apply a rotational force to a spring of a rollup or overhead garage door counterbalancing mechanism. The device has a rotatable driven member mounted in a housing. The housing and the driven member have slots with an open end adapted to receive the shaft of the overhead garage door counterbalancing mechanism. A coupling member is configured to mount to the driven member and connect the driven member to the winding cone of a garage door spring to apply rotational force to the spring. The housing with the driven member may be connected to the body of an existing power tool in place of the original tool head, or, the housing may be permanently combined with a motor and transmission to provide a special purpose tool.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application is a Continuation-in-Part of U.S. Non-Provisional Application No. 14/025,827 of the same title, and having a filing date of Sep. 13, 2013. 
     
    
     BACKGROUND OF INVENTION 
       [0002]    Field of the Invention 
         [0003]    Implements or devices for applying rotational force to a spring. 
         [0004]    Description of Related Art 
         [0005]    Power tools, using air or electric motors, are commonly used to rapidly turn nuts, bolts, and screws. However, these tools as currently marketed are not designed to apply twisting (torsion) forces to the springs of a counterbalancing garage door mechanism. 
         [0006]    Most of the foregoing door mechanisms utilize long coil springs that are placed under a rotational or torsion force to apply a lifting force to the door. The springs are concentrically positioned about a rotatable shaft mounted on fixed supports. The shaft carries drums accommodating cables, and these cables are attached to the bottom panel of the door so that when the drums are rotated, a lifting force will be applied to the door. The lifting force is transmitted from the torsion springs to the drums by the shaft. The springs must be anchored on one end, and the free end connected to a winding cone on the shaft, and the winding cone is then rotated to “load” the springs; e.g., place the springs under torsion force. When the torsion force is “loaded,” the winding cone is then connected to the shaft by a mechanical means, and the system is ready. 
         [0007]    Previously, long steel rods have been used to insert into open bores in the winding cone to rotate the winding cone and “load” the spring. The amount of force that can be applied to the spring is limited by the strength of the person using the rods, since rotating the winding cone in this manner is a manual operation. The procedure requires a considerable amount of time and can be dangerous as the spring becomes loaded with considerable force. 
         [0008]    While there have been other devices patented to introduce temporary mechanical power to “load” these door springs, such designs required some setup work over the shaft or at the winding cone for each spring, before they could begin to “load” the spring. Still other devices are for permanently installed mechanisms, increasing both the installation and subsequent repair costs. 
         [0009]    The current invention is safer to use than a manual procedure, and eliminates the setup times typical of past devices. 
         [0010]    It would be further desirable to to provide a device with relatively few moving parts to wear out, eliminating the increased costs associated with the permanently installed mechanisms. 
       SUMMARY OF THE INVENTION 
       [0011]    Embodiments of the invention relate to an apparatus for applying rotational force to an object, as a fastener, a fastener assembly, or a winding cone connected to a spring of a door counterbalancing mechanism. More particularly, some embodiments of the device may convert certain common power tools such as pipe threaders or handheld grinders into a tool to apply rotational force to a torsion coil spring of a door counterbalancing mechanism. Some embodiments of the device may be a standalone; i.e., special purpose tool. 
         [0012]    In one aspect, wherein a common power tool such as a drill or hand-held grinder is adapted to provide rotational force to a garage door spring, the device has a housing with a slot to accommodate the transverse insertion of a shaft of the overhead door counterbalancing mechanism. The housing is connected to a power tool, and more particularly to an output shaft of a power tool motor. The slot is formed in a driven member which may be the gear portion of a worm gear. The slot terminates in a semi-octangonal aperture that is formed to receive a post portion of a slotted coupling member. The coupling member has an engagement member configured to couple to a winding cone of the overhead door counterbalancing mechanism. The rotatable driven member is housed in the housing. When the slot of the driven member is aligned with the slot of the coupling member a passageway is formed for the introduction of the transverse section of a shaft of the overhead door counterbalance mechanism. A power transferring means; e.g., transmission, is contained in the housing, and may be a speed reducer of any conventional configuration as would be appreciated by those having skill in the art and which can possess any reduction ratio that can continuously and synchronously drive the driven member and the coupling member mounted thereto. A motor, such as an electric motor, is used to apply power to the transmission. One form of the coupling member includes a hook member aligned to engage an open bore in the winding cone. Those having skill in the art and access to this disclosure will appreciate that alternate engagement members can be incorporated with the coupling member. 
         [0013]    In another aspect of the present invention, the housing may be combined permanently with an electric motor and a transmission to create a specific use tool for rotationally winding a coil of a garage door assembly. 
         [0014]    One object of the present invention is to provide a power tool, usable with no set up required, to apply torsion forces to the spring of a door counterbalancing mechanism. 
         [0015]    Another object of the present invention is to provide an apparatus which is simple, safe and convenient to use and requires only one person. 
         [0016]    Another object of the invention is to provide a power tool for applying torsion forces to the spring of a door counterbalancing mechanism that is operable, with a minimum of time and effort, to apply the torsion forces to the spring sufficient to counterbalance the door. 
         [0017]    Another object of the invention is to provide a power tool that includes a motor that is compact in construction, relatively lightweight and efficient in use to apply torsion forces to the spring of a door counterbalancing mechanism. 
         [0018]    Yet another object of the invention is to provide a reliable power tool with a driven member having a slot to accommodate an object, as a shaft, so that the driven member can be concentrically located with the shaft whereby on rotation of the driven member rotational forces can be applied to an object mounted on the shaft. 
         [0019]    Other objects and advantages of the invention are embodied in the following description of the embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0020]      FIG. 1  shows an elevation view of a prior art sectional overhead door in the closed position; 
           [0021]      FIG. 2  shows a fragmentary elevation view of the prior art spring area of the counterbalancing mechanism; 
           [0022]      FIG. 3  shows a side elevation view of the housing portion of one embodiment of the invention, wherein the opposite side is substantially a mirror thereof; 
           [0023]      FIG. 4  shows a plan view of the top of the coupling member configured to mount to the housing portion; 
           [0024]      FIG. 5  shows a side elevation view of the coupling member; 
           [0025]      FIG. 6  shows a plan view of the bottom of the coupling member; 
           [0026]      FIG. 7  shows a side elevation view of the housing with mounted coupling member  122 ; 
           [0027]      FIG. 8  shows the combined housing with coupling member  122  mounted to the shaft of a garage door counterbalance mechanism, with an engagement hook  131  secured to a winding cone. 
       
    
    
     LISTING OF REFERENCED ELEMENTS 
       [0000]    
       
           80  garage door coil torsioning apparatus 
           100  housing 
           102  handle 
           106  driven member 
           108  snap ring 
           110  coupler retainer 
           112  housing shaft slot 
           114  worm gear 
           116  worm 
           117  shaft 
           118  transmission 
           120  motor 
           122  coupling member 
           123  coupler cap 
           124  coupler fasteners 
           125  coupler body 
           126  coupler post 
           128  coupler post prongs 
           130  coupler shaft slot 
           131  engagement hook 
           132  engagement recess 
           200  garage door counterbalance mechanism 
           201  garage door 
           202  garage door tracks 
           204  coil springs 
           206  shaft 
           208  shaft drum 
           210  shaft bearing 
           212  anchor cone 
           214  cone set screw 
           216  central support 
           218  winding cone 
           219  open bore 
           220  tabs 
           222  cable 
       
     
       DEFINITIONS 
       [0063]    Unless otherwise explained, any technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The singular terms “a”, “an”, and “the” include plural referents unless the context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described below. It should be understood that the objects, features and aspects of any embodiment disclosed herein may be combined with any object, feature or aspect of any other embodiment without departing from the scope of the invention. The term “comprises” means “includes.” All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety for all purposes. In case of conflict, the present specification, including explanations of terms, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
       DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0064]    In order that the various embodiments of the invention be fully understood, it is necessary to describe in sufficient detail the structure and function of coil type garage door counterbalance mechanisms. 
         [0065]    Explanation of Common Garage Door Assemblies: 
         [0066]    Prior Art  FIGS. 1 and 2  show common coil spring counterbalanced garage door assemblies.  FIG. 1  shows a conventional overhead door  201  in the closed position mounted against a wall. Overhead doors are usually made of metal, plastic or wood panels and have considerable weight.  FIG. 2  shows a counterbalance mechanism  200  which is used to facilitate the safe and easy opening and closing of door  201 . 
         [0067]    Counterbalance mechanism  200  is located above the top of door  201  and has a generally transverse shaft  206 . Transverse shaft  206  is typically either a hollow tube or solid bar, the material determined by the weight to be lifted. Opposite end portions of shaft  206  are supported in bearing supports  210 . The center portion of shaft  206  is supported by central bearing support  216  which is itself supported by a mount affixed to the wall. In some installations, shaft  206  may be supported in bearings on the remote ends of the garage door tracks  202 . Drums  208  are concentrically mounted to the shaft via a set screw in the positions shown, and rotate with the shaft. A cable  222  is wound about each drum, with one end of the cable tethered to the drum, and the other end attached to the lower end of the garage door. Shaft  206  is subjected to rotational forces by a pair of coil or helical springs  204  with typically one end of each coil spring  204  free to turn with the shaft  206 , terminating with a winding cone  218 , while the opposite end of each spring is constrained from turning by an anchor cone  212 . When door  201  moves from the open to the closed position, springs  204  are energized by the twisting action of shaft  206 , and the shaft  206  rotates as door  201  moves to its closed position, inducing sufficient torque into springs  204  to counterbalance the majority of the weight of door  201 . Springs  204  then have sufficient torque so that door  201  can be opened with little effort. When door  201  is in the open position, springs  204  must retain a small amount torque to keep cables  222  taut, preventing the accidental closing of door  201 . During door installation, winding cones  218  must be rotated and then secured to shaft  206  by set screws when door  201  is in the closed position, in order to set the initial amount of torque in springs  204  required for proper operation of door  201 . 
         [0068]    Winding cones  218  have a plurality of radial open bores  219  for the purpose of receiving long removable rods which are used to manually load the springs, to selectively hold and rotate the cones  1 / 4  turn per rod insertion, thereby applying torque to the springs. When sufficient torque is applied to the springs, winding cones  218  are secured to shaft  206  constraining the winding cones to rotate only with the shaft; i.e., not independently. 
         [0069]    To obviate the task of manually loading the springs which can be an exhausting and dangerous procedure, the present invention enables one person to easily place the springs  204  under tension by turning the winding cones  218 . Once the winding cones are loaded with the required torque, they are secured to shaft  206  in the same manner as with manual loading. 
         [0070]    Referring generally to  FIGS. 3-8 , an overhead garage door coil torsioning apparatus  80  comprises a housing  100 ; typically a cast metal housing/casing includes the following sections: a reduction gear section  118 , e.g., a transmission, worm section  116 , the driven member  106  section and handle  102 . The worm gear, that is, the gear portion  114  that the worm  116  drives may be the driven member having a slot formed the gear, or the driven member may be a slotted plate centrally mounted to gear  114 . Where there is a slot is formed in gear  114 , the gap width (w) of the slot  112  is less than the length of worm  116  so that the worm may bridge the extremities of the slot  112 , meaning that a leading or trailing end of the slot is always in contact with the worm when passing the worm  116  irrespective of the direction of rotation of the gear portion  114 , such that continuous non-intermittent rotational motion of the gear portion is possible. A motor housing  120   a  includes a reversible rotation electric motor  120  that is mounted to the transmission  118  of the housing  100 . While typically the motor is powered by household current; e.g., 115/120 VAC, battery operation is possible. An on-off trigger switch and a reversing switch, typically on the motor housing are used to control the power to the motor. 
         [0071]    In some embodiments, housing  100  may attach to an existing power tool body such as that of a hand held rotary grinder or a pipe threader by removing the existing head portion of the hand held power tool and substituting housing  100  which would be attachable to the hand held power tool by any suitable means, e.g., bolts and/or other fasteners. In such cases, a mounting portion of the housing would fastenably align with the original head portion of the grinder to the motor  120  housing of the hand held power tool. Once attached to the power tool motor housing, power is transmitted via the tool motor to the driven member  106 ; which in the particular embodiment depicted is gear  114  contained in the housing, worm  116  being driven by transmission  118  which is driven by the motor of the hand held power tool. Driven member  106  rests against a bearing shoulder of the housing of the same size as snap ring  108 , and is secured in the housing  100  by snap ring  108 . Driven member  106  has a slot  112  of a size required to accommodate shaft  206  and a concentric semi-octagonal hole to admit the coupling member  122 , which also has a slot  130  adapted to admit shaft  206 . Slots  112  and  130  are align-able and must be aligned in order to admit shaft  206 . The opening in the cast housing  100  is slightly larger than slot  112  to allow for motor-spin and any movement of driven member  106  after electrical power cut-off. 
         [0072]    Referring to  FIGS. 4-6  three views of coupling member  122  for connecting to and rotating the winding cones  218 . The cap  123  of coupling member  122  may be an alloy such as chrome steel with four holes provided for fasteners, bolts, etc., to attach cap  123  to body  125 . A stainless hook  131  is welded to cap  123  and engages an open bore  219  on either winding cone  218 , in order to wind either spring  204  to the required torque. Coupling member  122  is inserted into coupler retainer  110  in driven member  106  from the side toward the spring to be wound as shown in  FIG. 8 . The tool with engaged coupling member is typically placed directly adjacent the winding cone to be wound with the projection of the hooked member  131  inserted directly into one of the open bores  119  of the winding cone  218 . An alternative method of winding springs  204  is to omit cap  123  and engage tabs  220  on winding cones  218  into the slots  132  in body  125 . 
         [0073]    Body  125  of the coupling member has a post  126  with three prongs  128  which are configured to correspond with the semi-octagonal aperture/coupler retainer which firmly retains the coupling member  122  with an internal snap ring so that when coupler shaft slot  130  is aligned with shaft slot  112  of the driven member, and projections of the coupler post prongs  128  aligned with corresponding points of the semi-octagonal coupler retainer of driven member  106 . This positions coupling member  122  concentrically with driven member  106 , and with winding cones  218  and shaft  206 , perfectly aligning all parts for winding springs  204  to the required amount of torque. 
         [0074]      FIG. 7  shows the coupling member  122  mounted to the housing  100  of the apparatus  80  wherein coupler post  126  is inserted into the coupler retainer  110  and aligned therein by post prongs  128 . 
         [0075]      FIG. 8  shows the apparatus  80  attached to shaft  206  with engagement hook  131  of the coupling member  122  engaged with a winding cone  218 , wherein one end of the hook is inserted into an open bore  219  of the cone  218 . 
         [0076]    Housing  100  can also be used as a portable pipe threader to cut threads onto pipe ends by replacing coupling member  122  with the appropriate size pipe die and cutting blades. 
         [0077]    While there have been shown and described preferred embodiments of the invention, it is understood that changes in materials, size of the components, power transmission structures, coupling structures and other components can be made by those skilled in the art without departing from the invention.