Patent Abstract:
An indexing plunger is provided whereby a first downward force exerted on a hand grip or a lever will move a pin assembly downwardly and whereby a second rotating force exerted on the hand grip or the lever either clockwise or counterclockwise will lock the device into place by extending the locating pin and thereby locking it into place using the compression force exerted by an internal spring. This embodiment can assume a number of different physical configurations. In another preferred embodiment, the object is to provide an indexing plunger that moves the locating pin incrementally downwardly through the housing when the handgrip is rotated in the clockwise direction. At all times during the pin&#39;s downward movement, a compression spring maintains an opposing force on the handgrip.

Full Description:
FIELD OF THE INVENTION  
         [0001]    The device of the present invention is generally related to movable locating pins and the like. More particularly, it relates to devices such as indexing plungers that incorporate such locating pins and that are also used for mechanically positioning one item relative to another item whereby movement between the items is prevented and relative position is maintained between those items until it is desired or required that the items be repositioned.  
         BACKGROUND OF THE INVENTION  
         [0002]    In the experience of these inventors, there are many types and styles of locating devices, or indexing plungers, that are commercially available. Generally speaking, all share some commonality of purpose. For example, most indexing plungers of the type known to these inventors are used for the positioning, locating, holding or securing of one item in relative position to another item. That is, where two items are slidably mateable, for example, it may be desireable to prevent the relative movement between the items. Movement may be prevented by use of an indexing plunger that is mounted on one item and by the use of a mating receiver, such as an aperture, that is mounted on or defined within the second item. One example of this would be a telescoping pole where relative position is maintained between two cylindrical and mating pole members, one pole member having a slightly greater diameter than the other such that the pole members are slidable, one being slidable over and along the other. In this example, a first pole member may have a locating plunger mounted along its outer surface and a second pole member may have a plurality of holes, all aligned generally longitudinally along the second pole, such that engagement of the indexing plunger with any one of the holes will halt movement of the poles and secure the poles in position relative to one another. Disengagement of the indexing plunger allows the poles to slideably move until another position is desired, and so on. Generally, the indexing plunger provides for a retractable pin that can be mounted into any threaded hole. The retractable pin is typically spring biased such that the pin extends outwardly from the plunger in its normal position. In this fashion, the pin engages the mating aperture until the pin is forcibly pulled and retracted away from the aperture. The differences between the various models that are commercially available generally consist of the way in which the pin is extended and the distance it extends, and so on.  
           [0003]    In the experience of these inventors, the clearance between parts in a mechanical setting is often such that movement of the retractable pin in an indexing plunger is made difficult due to the close proximity to other parts of a machine. In that setting, there is only so much movement that can be realized by the pin and such amount of movement may be insufficient to securely hold the parts relative to one another. Also in the experience of these inventors, indexing plungers of current manufacture utilize locating pins that are just held in place by the reverse action of a spring. If someone or something inadvertently pulled out on the hand knob, or if someone or something inadvertently pushed the end of the locating pin, the pin could, and often will, disengage from its set position.  
         SUMMARY OF THE INVENTION  
         [0004]    It is, therefore, an object of the device of the present invention to provide a new, useful and uncomplicated indexing plunger that does not utilize a retractable pin in the usual sense. It is another object of the device of the present invention is to provide an indexing plunger that is designed to position, locate and hold an object in place. It is yet another object to provide an indexing plunger that is well suited for use in areas with space restrictions or tight clearances. It is still another object of the device of the present invention to provide an indexing plunger assembly that employs a “push and lock” or “push and turn” concept to extend the pin from the retracted position to the extended position and positively hold it, or effectively lock it, in that position. A further object of the present invention is to provide a device that can be constructed of brass, plastic, iron, steel, stainless steel or nearly any other material. It is yet another object of the present invention to provide a device that is simple in design, easy and inexpensive to manufacture, uses relatively few parts and is easy to employ.  
           [0005]    It is further an object of the present invention to provide a device that can be of any length or dimensions. It is also an object of the device of the present invention to provide a handgrip that can be of any configuration. It is yet another object of the present invention to provide an invention such that the locking pin can be part of the handgrip or part of the pin assembly. Yet another object of the device of the present invention is to provide a spring-loaded body that can be either threaded or unthreaded. Yet another object of the device of the present invention is to provide a housing that has an additional lock nut for securing the housing into varying positions. Yet another object of the device of the present invention is to provide for a plunger pin with various configurations including tapped, threaded, spherical, pointed, v-shaped, serrated, flat, concave, dog point or slotted.  
           [0006]    The device of the present invention has obtained these objects. In one preferred embodiment of the device of the present invention, an indexing plunger is provided whereby a first downward force exerted on a hand grip or a lever will move a pin assembly downwardly and whereby a second rotating force exerted on the hand grip or the lever either clockwise or counterclockwise will lock the device into place by extending the locating pin and thereby locking it into place using the compression force exerted by an internal spring. This embodiment can assume a number of different physical configurations as will become apparent in the detailed description that follows.  
           [0007]    In another preferred embodiment of the device of the present invention, the object is to provide an indexing plunger that effectively locks into place when the handgrip is rotated clockwise. The clockwise rotation moves the positioning pin incrementally downwardly through the housing. At all times during the pin&#39;s downward movement, a compression spring maintains an opposing force on the handgrip.  
           [0008]    The foregoing and other features of the device of the present invention will become further apparent from the detailed description that follows.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a cross-sectioned front elevational view of one embodiment of the device of the present invention and showing the locating pin in the retracted or “up” position.  
         [0010]    [0010]FIG. 2 is a cross-sectioned front elevational view of the same embodiment as shown in FIG. 1 and showing the locating pin in the extended or “down” position.  
         [0011]    [0011]FIG. 3 is an enlarged and exploded cross-sectioned front elevational view of the same embodiment shown in FIGS. 1 and 2.  
         [0012]    [0012]FIG. 4 is a right side elevational view of the housing of one embodiment of the present invention and showing an L-shaped lock with the lock pin in the “up” or unlocked position.  
         [0013]    [0013]FIG. 5 is a right side elevational view of the embodiment shown in FIG. 4 with the lock pin in the “down” or locked position.  
         [0014]    [0014]FIG. 6 is a cross-sectioned front elevational view of another embodiment of the device of the present invention and showing the lever lock and locating pin in the retracted or “up” position.  
         [0015]    [0015]FIG. 7 is a cross-sectioned front elevational view of the same embodiment as shown in FIG. 6 and showing the lever lock and the locating pin in its extended or “down” position.  
         [0016]    [0016]FIG. 8 is a right side elevational view of the top of the housing that displays the locking groove.  
         [0017]    [0017]FIG. 9 is a cross-sectioned front elevational view of yet another embodiment of the device of the present invention and showing the “posi-turn” indexing plunger.  
         [0018]    [0018]FIG. 10 is an exploded and cross-sectioned front elevational view of the posi-turn indexing plunger shown in FIG. 9. 
     
    
     DETAILED DESCRIPTION  
       [0019]    Referring now to the drawings in detail, wherein like numbered elements correspond to like elements throughout, FIGS. 1 through 5 display one preferred embodiment of the device of the present invention. This embodiment, the “push-lock” indexing plunger, as these inventors like to call it, is generally identified  200 . The push-lock indexing plunger  200  is generally comprised of a handgrip  210 , a locating pin assembly  220 , a housing  230 , and a compression spring  240 . These elements may be constructed of brass, plastic, iron, steel, stainless steel, or nearly any other material.  
         [0020]    The locating pin assembly  220  is a generally cylindrical component having four main features, a main body  221 , locating pin  222 , a circular aperture  223  through the main body  221 , and a threaded top  224 . See FIG. 3. Although the top  224  is shown as threaded, it is to be understood that any conventional attachment means, such as a barbed top (not shown) could also be used. The difference between the diameter of the main body  221  and the diameter of the locating pin  222  provides a ledge  225 . The purpose of the ledge  225  will become apparent later in this detailed description. The threaded top  224  of the locating pin assembly  220  threads into the bottom  211  of the handgrip  210 . If a barbed top were incorporated into the locating pin assembly  220 , the top  224  of the locating pin assembly  220  would be pressed into the bottom  211  of the handgrip  210 .  
         [0021]    Although the handgrip  210  is shown as being generally cylindrical in shape, it is to be understood that the handgrip  210  could be formed in almost any shape that is capable of being gripped by a human hand or manipulated by a tool or other means. The bottom  211  of the handgrip  210  has a circular aperture  212  that is large enough to accommodate the upper portion of the main body  221  of the locating pin assembly  220 . At the top of this aperture  212  is another threaded circular aperture  213 . The threaded top  224  of the locating pin  220  is functionally adapted to thread into and be received by the threaded aperture  213 . Again, if a barbed top were incorporated into the locating pin assembly  220 , the aperture  213  would not need to be threaded. The top  214  of the handgrip  210  provides a convenient gripping surface for a person or for a tool of some sort such that the handgrip  210  is easily rotatable.  
         [0022]    The housing  230  is formed generally in the shape of a hollow cylinder. See FIG. 3. The housing  230  has several features including a lower portion  231 , which can be threaded as shown (but need not be threaded), a pin aperture  232  at the base of the lower portion  231 , an upper portion  233 , an aperture  234  through the upper portion  233  and a hollow interior  235 . The upper portion  233  of the housing  230  may also be formed, when viewed from the top, as a square, a hexagon or a circle with flats for securing the housing  230  to a threaded (or unthreaded) base member  250 . See FIGS. 1 and 2.  
         [0023]    In the application shown, which application is by example only and not in any way to be construed as a limitation of the device of the present invention, the base member  250  is attached generally perpendicularly to an outer tube member  252 . The outer tube member  252  includes an aperture  254  that is axially aligned with the pin aperture  232  of the housing  230  when the housing  230  is threadably received within the base  250 . An inner tube  256  is provided that is functionally adapted to be received within and be longitudinally movable within the outer tube  252 . A plurality of inner tube apertures  258  are defined within the inner tube  256 , each being functionally adapted to receive a locating pin  222  therewithin for positioning the inner tube  256  relative to the outer tube  252  as such is desired or required. See FIG. 2. Again, it is to be understood that this application is for illustration purposes only. Any number of similar locating applications could be devised and utilize the device of the present invention. The advantage of the present indexing plunger  200  in this application is that the clearances for releasing the locating pin  222  are not dictated by the distance that the handgrip  210  can be axially displaced. Rather, it is the amount of travel required to disengage the grooved pin  229  from the housing  230 .  
         [0024]    The interior  235  of the housing  230  is cylindrically shaped and designed to accommodate the pin assembly  220  and the compression spring  240 . The interior  235  of the housing  230  narrows abruptly near the base  236  of the housing  230  creating a flange  237 . At the center of the base  236  is the pin aperture  232 . The pin aperture  232  permits upward and downward movement of the pin  222  therethrough. The pin aperture  232  is preferably large enough to permit passage of the pin  222  but not so large as to prevent precision placement of the pin  222 .  
         [0025]    Again referring to FIG. 3, a grooved lock pin  229  locks the locating pin  222  into place. In assembly, the push-lock indexing plunger  200  is first positioned. Next, the operator of the plunger  200  depresses the handgrip  210  until the aperture  223  in the main body  221  lines up axially with the apertures  234 ,  238  in the housing  230 . The user then presses the grooved lock pin  229  into the apertures  223 ,  234 ,  238  to secure the locating pin  222 . It is to be understood that the pin  229  could assume a number of different shapes or forms and that the insertion of the pin  229  into the locating pin  222  could be accomplished by any suitable design or manufacturing expediency.  
         [0026]    The flange  237  and the ledge  225  between the main body  221  of the pin  220  and the locating pin  222  operate cooperatively to contain the spring  240  therebetween. The spring  240  provides for tension on the pin assembly  220  such that when the grooved lock pin  229  is removed, the locating pin  222  retracts into the housing  230 .  
         [0027]    As shown in FIGS. 4 and 5, the grooved lock pin  229  moves downwardly along the L-shaped slot  234  that is defined within the housing  230 . This particular embodiment also requires the user to depress the handgrip  214  and then rotate it thereby moving the pin  229  horizontally along the bottom portion  244  of the L-shaped slot  234 . The bottom portion  244  of the L-shaped slot  234  could also include an enlarged opening (not shown) such that the pin  229  is effectively “caught” within the slot. Alternatively, the bottom portion  244  could be defined as a slight incline relative to the horizontal for the same purpose. The slot  234  could also be formed in a “J” configuration or in any other configuration that maintains the spring  240  under compression.  
         [0028]    [0028]FIGS. 6 and 7 illustrate another preferred embodiment of the device of the present invention, termed by these inventors as the “lever-lock” embodiment of the indexing plunger, generally identified  100 . This particular embodiment of the device of the present invention is comprised of a unitary indexing lever and pin  110 , a compression spring  120 , a housing  130  and a retaining ring  140 . The indexing lever and pin  110  is a generally L-shaped and rod-like component of the indexing plunger  100 . The indexing lever and pin  110  in this particular embodiment has three main features. The lever portion  112  of the indexing lever and pin  110  is formed generally orthogonal to the pin  114  portion of the indexing lever and pin  110 . The lever  112  allows for easy lifting and lowering of the pin  114 . The lever  112  also provides for easy rotatability of the pin  114  relative to the housing  130 . The indexing lever and pin  110  also features a waist  116  on the pin  112 . The waist  116  is formed generally orthogonal about the pin and protrudes from the pin  112  in all directions to form a disk, or waist,  116  around a central portion of the pin  112 . The purpose of these and other features will become more apparent later in this detailed description.  
         [0029]    The housing  130  is generally formed in the shape of a hollow cylinder, as in previous embodiments. The housing  130  has several features including a lower housing portion  131 , which can be threaded as shown (but need not be threaded), a pin aperture  132  at the base of the lower portion  131 , an upper section  133 , a locking groove  134  and a hollow interior  135 . The interior  135  of the housing  130  is cylindrically shaped and functionally adapted to accommodate the pin assembly  110  and compression spring  140  therewithin. The interior  135  of the housing  130  narrows abruptly near the base  136  of the housing  130  thereby creating a flange  137 . At the center of the base is the pin aperture  132 . The pin aperture  132  permits upward and downward movement of the pin  114  relative to the housing  130 . The pin aperture  132  is preferably large enough to permit passage of the pin  114  but not so large as to prevent precise placement of the pin  114 .  
         [0030]    The interior  134  of the housing  130  abruptly narrows so as to provide a flange  137  such that the compression spring  140  is contained at its upper end  141  by the waist  116  of the pin  110  and at its bottom end  142  by the flange  137 . In this manner, the compression spring  130  provides some resistance against a downward force and provides upward resistance against the upper portion  133  when the lever  112  is locked into place.  
         [0031]    As shown in FIG. 8, the upper portion  133  of the housing  130  features a locking groove  134  defined within the housing  130  for receiving the indexing lever  112 . The locking groove  134  can be designed in any number of ways but the basic principle behind the operation of the locking groove  134  is to provide a locking groove  134  to accommodate the lever  112  such that when the lever  112  is pushed down, the pin  114  descends and the lever  112  goes into the locking groove  134 . The locking groove  134  provides a further aperture portion, or locking aperture portion,  138  disposed generally perpendicularly either clockwise or counterclockwise from the locking groove  134 . The pin  114  is permitted to rotate within the interior  135  of the housing  130  such that the pin  114  can be locked in a downward position by rotating the lever  112  into the locking aperture  138 .  
         [0032]    In application, the use of the “lever lock” assembly  100  is substantially similar to that of the “push-lock” indexing plunger  200 . Instead of pushing and rotating the handgrip  210 , however, the indexing lever and pin  110  is used.  
         [0033]    Yet another embodiment of the device of the present invention is very similar to the lever lock embodiment of the present invention. This alternative embodiment (not shown) employs a locating pin assembly similar to that of the push-lock indexing plunger assembly with the exception of employing a cam-shaped lobe at the base of the handgrip, which lobe is functionally adapted to slide in to and out of a slot defined within the housing. Another variation (also not shown) would incorporated a recess defined within the lower portion of the locating pin such that one or more spherical ball bearings could be pushed outwardly of the locating pin when the handgrip is depressed. Other variations are also possible, each of which utilizes the push-lock concept of the present invention.  
         [0034]    Referring now to FIGS. 9 and 10, the device of the present invention could be embodied in yet another configuration, termed by these inventors as the “posi-turn” positioning plunger, generally indentified  300 . The posi-turn plunger  300  provides for a variably positionable indexing plunger. Like the other embodiments, the posi-turn positioning plunger  300  has a handgrip  310 , a locating pin assembly  320 , a housing  330  and a compression spring  340 . The upper portion  312  of the handgrip  310  can be circular, hexagonal or nearly any shape that is capable of being gripped by a human hand or manipulated by a tool or other means. The lower portion  314  of the handgrip  310  provides a generally circular aperture  316  such that the handgrip  310  is in the shape of an inverted cup. In the center of the aperture  316  is a circular depression  317 . In the center of the circular depression  317  is a threaded aperture  318 .  
         [0035]    Unlike the previous embodiments, the posi-turn positioning plunger  300  features an internal mating thread mechanism that provides for an infinitely adjustable plunger pin  324 . The internal thread  323  is machined axially on, and as part of, the locating pin assembly  320 . The locating pin assembly  320  is generally cylindrically shaped and has a threaded, or barbed, top  321  that is functionally adapted to screw, or be pressed, into and be received by the threaded, or plain hole, aperture  318  of the handgrip  310 . The opposite end of the locating pin assembly  320  comprises the locating pin  324  itself.  
         [0036]    The housing  330  of this embodiment also generally assumes the shape of a hollow cylinder. The top  333  of the housing  330  features an aperture  334 . This aperture  334  continues at uniform depth and then narrows abruptly, thereby creating a flange  335 . Below the flange  335 , the interior of the housing  330  is threaded  332 . The internal threads  323  of the locating pin assembly  320  are functionally adapted to mate with the housing threads  332  located on the inside of the housing  330 . Thus, by rotating the handgrip  310 , the pin  324  will either ascend to a point where it no longer mates with the housing threads  332  or descend to the user&#39;s preference through the aperture  331  in the housing  330 .  
         [0037]    The posi-turn indexing plunger also employs a compression spring,  340 . See FIG. 9. The compression spring  340  has a first bottom end  341  that rests on the flange  335  of the housing  330  and is contained at its second top end  342  by itu the circular depression  317  in the handgrip  310 . The properties with respect to the spring in this embodiment of the device, as in other embodiments, such as the stiffness, diameter of the coil, and number of coils can be varied to provide different amounts of resistance.  
         [0038]    Another embodiment of the device of the present invention is very similar in operation to the push-lock indexing plunger  200  but utilizes a feature of the posi-turn indexing plunger  300  embodiment of the present invention. This alternative embodiment (not shown) employs engageable threads, not situated between the locating pin and the interior surface of the housing as shown in FIG. 9, but between the exterior surface near the top of the housing  330  and the interior of the handgrip  310 . Downward movement of the handgrip  310 , followed by rotation of the handgrip  310 , will effect a locking of the locating pin  324  into its set position as previously described.  
         [0039]    Based upon the foregoing, it will be apparent that there has been provided a new, useful and uncomplicated indexing plunger that does not utilize a retractable pin in the usual sense; that provides an indexing plunger that is designed to position, locate and hold an object in place and that is well suited for use in areas with space restrictions or tight clearances; that employs a “push and lock” or “push and turn” concept to extend the pin from the retracted position to the extended position; that provides a device that can be constructed of brass, plastic, iron, steel or nearly any metal; that is simple in design, easy and inexpensive to manufacture, uses relatively few parts and is easy to employ.  
         [0040]    It will also be apparent that the present invention provides a device that can be of any length or dimensions; that provides a handgrip that can be of any configuration; that provides a locking pin that can be formed as part of the handgrip; that provides a spring-loaded body that can be either threaded or unthreaded; that provides a housing that has an additional lock nut for securing the housing into varying positions; that provides for a plunger pin with various configurations including tapped, threaded, spherical, pointed, v-shaped, serrated, flat, concave, dog point or slotted.

Technology Classification (CPC): 5