Abstract:
A locking mechanism for elongate tools that are designed to engage objects from remote distances and that have engagement elements located on a distal end of a rod, a handle on a proximate end of said rod, a controller on said handle to control the engagement elements, and a linkage between the controller and the engagement elements to control the engagement elements is disclosed. The locking elements include a saw tooth receiving surface that is rigidly affixed to a trigger and a stop member having complementary saw tooth extensions. A switch member controls the movement of the stop member into engagement and out of engagement with the receiving surface which thereby locks and unlocks the movement of the trigger.

Description:
[0001]    This invention relates to an improvement for tools designed to engage objects from remote distances. This is a division of U.S. application Ser. No. 10/302,861. The applicant claims the benefit of the filing date of U.S. Provisional Application No. 60/384,820 and U.S. application Ser. No. 10/302,861. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    There are a wide variety of tools designed for picking up objects or manipulating objects from a distance. One common application for such tools is use by maintenance workers to pick-up debris for subsequent disposal. A tool with an elongate handle allows manipulation of the object without the need to bend over or to directly handle the material. Such tools are also useful for individuals that have physical handicaps that may impede their ability to bend over and reach the ground. There are also numerous household applications for such tools including retrieval of materials from high shelves or from under furniture. Another common application for such tools is for changing light bulbs from recessed lighting fixtures. Another entire class of devices that operate in a similar manner and perform a similar function as the pick-up tools described above are marketed as toys. Other tools may have blades on the distal end for cutting that may be used for a wide range of uses including those tolls used in the surgical field and tools used for trimming high branches.  
           [0003]    Common elements that are shared by such devices that are addressed by the improvement disclosed herein include (1) an elongate shaft having (2) a handle on one end and, (3) engagement elements on the opposite end, (4) a controller element on the handle and (5) a linkage from the controller element to the engagement elements. The user of the these tools may manipulate a controller, such as a lever or trigger, that is provided on the handle end of the device to operate the engagement elements that are provided on the opposite end of the elongate shaft. The engagement elements may include arrangements such as claws, arms, scoops, calipers, tongs, blades or cups. In typical designs, the control lever pulls an internal linkage that draws together the engagement elements that are biased apart by springs.  
           [0004]    Exemplary arrangements of such devices are disclosed in the U.S. Pat. No. 4,962,957 (the “&#39;957 Patent”), U.S. Pat. No. 4,709,839 (the “&#39;839 Patent”), U.S. Pat. No. 3,527,492 (the “&#39;492 Patent”), U.S. Pat. No. 4,613,179 (The &#39;179 Patent), U.S. Pat. No. 4,669,769 (the &#39;769 Patent) and U.S. Pat. No. 6,257,634 (the &#39;634 Patent).  
           [0005]    A desirable feature that is sometimes incorporated on these devices is a locking mechanism that enables the engagement elements to be retained in a fixed position. A locking features allows a user of the device to retain the engagement elements in a closed position and in contact with an object and thereby allow a user to release pressure on the controller while maintaining control over the object. Consequently, a user can use his or her free hand to further manipulate the object, either directly, or indirectly by using the elongate shaft. Allowing the user to release pressure on the controller yet maintain engagement of the object also adds a convenience feature.  
           [0006]    There have been a number of alternative manners to accomplish locking engagement elements on grabber tools that are disclosed in the prior art. For example, the patent to Moyer, U.S. Pat. No. 1,120,735, discloses a segment that can be that can be manipulated by a lever that in turn may be secured in place by a pawl. The pawl is biased against the ratchet segment by a leaf spring. The &#39;957 patent discloses an alternative manner in which to lock the engagement elements of a pick-up tool that allows the trigger to be released while maintaining pressure on the object. U.S. Pat. No. 5,823,590 to Forrest et al. discloses yet another alternative method of locking the engagement elements thereby allows a user to manually secure the central linkage in fixed position. U.S. Pat. No. 6,438,891 to Aboczky provides a spring locking mechanism.  
           [0007]    While, there exist numerous types of devices and a variety of alternative manners in which to lock engagement elements in fixed positions, many of the efforts disclosed in the prior art have involved fairly complex arrangements and require multiple parts. In general, increased complexity of a proposed device is associated with increased expense in connection with manufacturing and with respect to the costs of the parts required to achieve the feature. Accordingly, there continues to remain a demand and a commercial market for devices that have a simple and inexpensive locking arrangement. A further desirable feature to provide with elongate engagement tools is the ability for the device to fold or collapse. Because these devices employ an elongate rod, the devices are somewhat cumbersome in connection with shipping, handling, display and storage. While it is desirable to provide a manner in which to collapse the device, the manner in which the collapse is affected must accommodate the linkage between the controller and engagement elements and must also maintain sufficient strength to support objects when the elongate member is in an extended position. While the prior art has recognized this need, there remains room for improved alternative and effective manners to achieve these goals. In this regard, for example, U.S. Pat. No. 4,613,179 relies upon a stop pin 71 that is designed to work only when the device is in an upright position. U.S. Pat. No. 5,823,590 discloses a telescopic arrangement to collapse a grabber device. U.S. Pat. No. 4,231,603 discloses a grabber device with a hinge fixture that allows the proximal and distal ends of an elongate rod to be aligned in different directions.  
           [0008]    It is an object of the present invention to provide a new locking arrangement for the engagement elements of a pick-up tool that is simple to manufacture and assemble and that uses only a few parts. A further object of the present invention is to provide an engagement device that has a locking device that can be easily manipulated by the user. A further objective of the invention is to provide a locking hinge on the elongate arm or rod that allows the devices to fold yet maintain strength when in an extended position.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention relates to both a new locking arrangement and a folding hinge structure for the engagement of such devices described above. The invention allows the user of such a device to engage an object and then manipulate a sliding switch to lock the engagement elements in a fixed position. The switch causes a stop member, oriented in a direction transverse to the switch, to engage a control surface and prevent movement of the controller. The switch is provided on the handle so that it can be manipulated by the user&#39;s thumb while he or she operates the controller for the device. The control surface is fixed and integrated with the controller that controls the engagement elements that are positioned on the opposite end of an elongate rod. The device also incorporates a hinge feature on the elongate rod that enables the elongate arm to be folded in half so that the device may be shipped and stored conveniently. The hinge, which is provided at a midpoint along the elongate rod, does not significantly diminish the strength of the rod. The hinge uses a pin that has axial sections that alternate from sections having a circular profile to sections having an aster shaped profile. The pin may be aligned in a first locked position wherein the aster shaped segment fit into corresponding aster shaped cavities within the knuckle that prevents the leaves from movement. The pin may be positioned to occupy an alternate second position wherein the sections of the pin having a round profile is aligned in the aster profiled cavity thereby allowing the leaves to pivot with respect to each other. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a perspective view of the pick-up device according to the invention;  
         [0011]    [0011]FIG. 2 is a perspective view of the device shown folded about the hinge;  
         [0012]    [0012]FIG. 3 is an exploded view of the handle of the invention;  
         [0013]    [0013]FIG. 4 is a bottom view in elevation of the switch element used with the locking feature of the invention;  
         [0014]    [0014]FIG. 5 is a perspective view of the switch element used with the locking feature of the invention;  
         [0015]    [0015]FIG. 6 is an exploded view of the hinge element of the invention;  
         [0016]    [0016]FIG. 7 is a bottom view of the exterior segment of the pin used with the hinge element of the invention.  
         [0017]    [0017]FIG. 8 is a side view in elevation of the exterior segment of the pin used in connection with the hinge element of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0018]    Now referring to FIG. 1, a preferred embodiment of the elongate grabber tool  8  is depicted in an extended position. Grabber tool  8  incorporates engagement cups  10  on a distal end of a elongate hollow rod  12  and a pistol grip  14  on the opposite proximal end. A trigger  16  is provided adjacent to pistol grip  14  for manipulation by a user&#39;s fingers. As shown on the side of pistol grip  14 , a switch  18  is provided that effects a locking feature of the engagement elements of the device. At a medial point on elongate hollow rod  12  is hinge  20  that allows elongate rod  12  to fold. FIG. 2 depicts the rod in a folded position wherein the distal end of elongate rod  12  is folded back on the top side and adjacent to pistol grip  14 .  
         [0019]    Now referring to FIG. 3, trigger  16  extends from and is connected to the handle at axis or pivot point  30  that is located near the top of the pistol grip  14 . A connecting pin  32  transects handle side  25   a , the trigger half  16   a , trigger half  16   b  and handle side  25   b . Trigger  16  extends through a slot or opening provided between the forward sides of pistol grip  14  and allows for limited pivotal movement with respect to the axis  30 . As seen on trigger side  16   b , a cavity is provided to retain a nipple (not shown) which is provided on the end of a cable (not shown) that connects trigger  16  to the engagement elements on the distal end of the tool. The engagement elements, which are biased apart by spring members  31  are drawn together by pulling connector members  29  toward the handle  14  via the central cable. Control surface  35  is an arcuate notched surface that is integral with trigger half  16   a  and on which is provided a series of saw-tooth notches  38 . The arc is formed so that each saw tooth extension is approximately equidistant to the pivot point  30 . The notches  38  are adapted to receive the end projections  40  of a stop member  42 . Stop member  42  is engaged or disengaged by the lateral manipulation of switch  44 . Stop member  42  also is provided with a pin member  48  that is engaged by switch  44 . Stop member  42  can be disengaged by either movement of the switch in the opposite direction or by application of a force against the trigger that will push the stop member from its position. Stop member  42  is locked into place and in engagement with notches  38  on the arcuate control surface  35  by use of a mechanical locking engagement wherein switch  44  stays in position by frictional engagement.  
         [0020]    [0020]FIGS. 4 and 5 depict the rear side of switch  44 . As best seen in FIG. 5 extensions  60 ,  61 ,  62  and  63  have a projections that extend laterally away from the extensions so that the switch  44  will snap fit into opening  50  and be retained within the opening. For example, surface  70  of projection  60  will engage the interior surface of the handle side  25   a  adjacent to the opening  50 . Since the projections only extend toward the top and bottom of the switch, the arrangement allows for the lateral movement of the switch  44  within opening  50 . Walls  65  and  67  define groove  72  into which the pin member  48  of stop member  42  is received. Lateral movement of switch causes the side walls  65  and  67  to move pin  48  thereby causing the stop member to move up or down and in or out of engagement with the control surface  35 .  
         [0021]    In operation, a user can use the device in a manner that allows free movement of cups or, by manipulation of the switch can cause the stop member to engage the notches on the trigger and therefore lock the movement of the device. The stop member can be disengaged by pulling on the trigger, which forces the teeth  40  of stop member  42  out of engagement with the opposite teeth  38  on control surface  35 . The teeth  40  may also be disengaged from the opposite teeth  38  on control surface  35  by lateral movement of switch  44 .  
         [0022]    While an integral saw-toothed notched control surface  35  is depicted as a preferred embodiment, it is contemplated that other arrangements could be advantageously employed to lock the trigger. For example, a side view of the control surface could resemble a round or square waveform that has an opposite and complementary profile of teeth provided on a stop member. In a further contemplated embodiment, the control surface may be comprised of a series of cavities that have sidewalls oriented transverse to the control surface and the stop member includes an extension that can be received in the cavities. For example, in this alternative contemplated embodiment, a series of annular cavities are provided on the control surface that can receive a peg that extends from the stop member. In yet further contemplated embodiments of the invention the stop member is made of conical shaped projections or pyramid shaped projections that are received in opposite and complementary shaped cavities.  
         [0023]    The locking arrangement according to the invention uses only a few parts and can therefore be economically manufactured and assembled. As described herein, the locking feature further allows for the stop member to engagement the control surface along the entire range of motion of the control surface  35  and range of the trigger  16 . The switch for the lock can be manipulated by the user&#39;s thumb while the handle  25  of the device is held in the user&#39;s hand.  
         [0024]    While the controller depicted in the preferred embodiment is a trigger designed to be engaged by multiple fingers of the user, the applicant contemplates that alternative arrangements of the trigger or controller may also be provided. For example, in an alternative embodiment the trigger may be manipulated by a user&#39;s single finger. In yet another contemplated alternative embodiment, the trigger may be displaced on the rear side of the stationary handle. Further, while in the preferred embodiment the engagement elements are opposite engagement cups, it is also contemplated that other engagement elements may also be used and that may depend on the intended application.  
         [0025]    As best shown in FIG. 6, in a preferred embodiment of the invention the elongate shaft is provided in two sections, a distal section  101  and a proximal section  103 . The distal section  101  and the proximal section  103  are connected by a locking hinge structure  105  that enables the device to be folded. Hinge  105  includes a forward hinge section  111  composed of opposite halves  111   a  and  111   b  and a rearward section  120  composed of opposite halves  120   a  and  120   b . Halve  120  includes a shank  135  and a two a flat knuckle sections  137  and  139  that extend from shank  135 . Separating knuckle section  137  from section  139  is a gap that has an axial dimension about the same distance as the as the width of one of the respective knuckles. This distance is also approximately the same as the length of sections  82  and  84  of the hinge pin.  
         [0026]    The knuckle sections  115  and  118  extend from the distal end of the hinge segment  111  and are positioned on the exterior lateral sides of the hinge. When assembled, sections  115  and  137  are adjacent to one another and define a portion of an axial channel that extends transverse to the direction of the elongate rod. When the grabber device is in its extended position, wall  201  comes into contact with wall  203  and prevents further rotation in one direction.  
         [0027]    The hinge pin is made of exterior section  170  and a retention member  172 . Retention member includes rounded head section  172  on the end of shank member  175 . Shank member  175  of retention member  172  is received in opposite and complementary cavity  178  that is provided in the exterior section  170 . As seen in FIGS. 7 and 8 the exterior shank section  179  has a number of sections along its axial length. As best seen in FIG. 7, a bottom view of the exterior section  170 , section  185  has an aster or “star shaped” axial section. Sections  183  and  181  of the pin have the same star shaped profile. Separating the star shaped sections are sections  182  and  184  that having circular or round axial sections. As best seen in FIG. 6 the exterior section of the pin is inserted through the axial cavity formed when the knuckles are aligned.  
         [0028]    The arrangement described above allows the hinge pin to be positioned in alternative positions including a first position wherein the rounded axial sections  183  and  184  of the pin are aligned within knuckle sections  137  and  139 . In this first position the hinge section is allowed to rotate about the pin. Application of pressure on the rounded head allows the pin to be moved in an axial direction through the channel to a second position where the are locked with respect. In the locked position the star shaped axial sections  181 ,  183  and  185  of pin  170  are aligned within the aster shaped cavities defined by the knuckles  201   203   139  and  118 . In this position the front leaf section does not move with respect to the rearward leaf section section.  
         [0029]    The hinge allows the device to be positioned in the extended position as depicted in FIG. 1 or in the folded position as depicted in FIG. 2. When the device is in the extended position, the hinge may be locked into position wherein the hinge leaves are fixed with respect to one another.  
         [0030]    While the preferred embodiments have been described herein, those skilled in the art will recognize that certain details may be changed without departing from the spirit and scope of the invention. Thus, the foregoing specific embodiments and applications are illustrative only and are not intended to limit the scope of the invention. It is contemplated that the invention will functional and effective in diverse applications where it is desirable to lock elements that are designed to engage or otherwise manipulate objects from a remote distance. Likewise, although the locking hinge structure is particularly useful in connection with elongate grabber tools, the hinge may also be employed on other rod statures where there is need.