Abstract:
An extendible and retractable lead that can be extended or retracted and locked in position in a single action. The lead comprises a casing ( 4 ) housing a reel ( 14 ), a lead windable about the reel, the casing having an outlet ( 8 ) for passage of the lead and further comprising a moveable member ( 12 ) for engagement and disengagement with the reel, a part ( 32 ) of the moveable member being engageable with a retainer ( 52 ) on movement of the member towards the reel to lock the member against the reel in a single action.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
         [0001]    “Not applicable”.  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    “Not applicable”.  
         BACKGROUND OF THE INVENTION  
         [0003]    1. Field of the Invention  
           [0004]    The present invention relates to an improved extendible and retractable lead, particularly but not exclusively for use as an extending dog lead.  
           [0005]    2. Description of the Related Art  
           [0006]    Extending dog leads that enable the length of the lead to be altered have been widely available for a number of years. Generally, the leads are rotated around a reel within a handle part of the lead and a member can be pushed against the reel to prevent movement thereof. A separate locking mechanism then has to be operated to maintain the member in this position thereby preventing further movement of the reel and thus maintaining the lead at a given length. However, these types of leads can be difficult to operate because they involve two actions, pushing a trigger onto the reel and then moving a further member, for example in the form of a switch, to lock the trigger against the reel.  
           [0007]    It is an object of the present invention to provide an extendible and retractable lead that can be operated in a single action.  
         BRIEF SUMMARY OF THE INVENTION  
         [0008]    Accordingly, the present invention provides an extendible lead comprising a casing housing a reel, a lead windable about the reel and a retainer, the casing having an outlet for passage of the lead and further comprising a moveable member for engagement and disengagement with the reel, characterised in that a part of the moveable member is engageable with the retainer on movement of the member towards the reel, thereby locking the member against the reel in a single action.  
           [0009]    The casing is preferably formed of two halves that may be secured together by suitable fixing means. The casing preferably includes an elongated oval passage therethrough for serving as a handle. The two halves of the casing are preferably injection moulded components, the inner profile of the casing being shaped appropriately to house and retain the positioning of the internal components contained therein. The casing is preferably made of a tough, rigid plastics material, such as polypropylene.  
           [0010]    Any conventional reel may be employed in the device of the present invention for winding of the lead therearound. Preferably, each end of the reel is provided with parallel flanges extending perpendicularly around the periphery thereof for encasing the lead. The flanges may be provided with ribbing on the outer surface thereof.  
           [0011]    The lead may made of any suitable material for forming an elongated strap, for example the lead may be formed of a length of cord attached to a further length of strapping or may be formed of strapping only, for example being made of nylon. The outlet provided in the casing for passage of the lead is preferably crescent-shaped to eliminate twisting of the lead. Suitable fastening means are attached to the end of lead to enable it to be fastened to, for example, a collar.  
           [0012]    The moveable member preferably extends from the exterior of the casing into the interior thereof, the casing being provided with an appropriate aperture for passage of the member. The part of the moveable member that engages with a retainer is preferably in the form of a resiliently deformable latch extending from the member. Preferably, the latch is in the form of a living hinge. The moveable member preferably comprises a knob or button part located exteriorally to the casing for imparting movement to the member connected to two parallel side arms within the interior of the casing that, in the forward position, co-operate with the ribs on the reel to prevent rotation thereof. The latch part is preferably within the casing and extends from the knob or button part between the side arms. Preferably the latch extends approximately three quarters along the length of the side arms. The latch is preferably T-shaped, being comprised of a lever and cross bar. Preferably the cross bar is angled obliquely with respect to the lever. It is to be appreciated that the latch should be formed of a material having a degree of flexibility, such as an acetyl material.  
           [0013]    The moveable member is preferably provided with biasing means. Preferably, a spring extends between the moveable member and abutment means. Contact with the abutment means biases the spring towards the end of the member. Preferably, the side arms are relieved of material along the length thereof to provide slots. The abutment means preferably extends through the slots.  
           [0014]    The retainer is preferably provided within the casing. Preferably, the retainer is a C-shaped catch, the back part of the retainer being closest to the latch when the moveable member is disengaged from the reel. Pushing the knob of the member causes it to move towards the reel and, in doing so, the latch is forced over the back of the retainer and into the recess. This locks the member against the reel. Pushing of the knob a second time causes the latch to be forced out of the retainer thereby enabling the moveable member to move back from the reel.  
           [0015]    Preferably, the device is also provided with guides for directing the latch of the member into and out of the retainer. Preferably, the guides are substantially parallel to the contours of the retainer. More preferably, two sets of guides are provided around opposing sides of the retainer, the guides meeting at an apex that points towards the centre of the recess of the retainer. Guides may also be provided to aid movement of the side members.  
           [0016]    Preferably, the guides and retainer are formed integrally with the moulded casing. A lubricant may be provided to assist in the smooth operation of the working components.  
           [0017]    In a preferred embodiment of the present invention there is provided an extendable and retractable lead comprising a casing housing a reel, a lead windable about the reel and a retainer, the casing having an outlet for passage of the lead and further comprising a moveable member for engagement and disengagement with the reel, the moveable member having side arms and a resiliently deformable latch, whereby movement of the member towards the reel causes the latch to engage with the retainer and thereby lock the side arms of the member against the reel. 
       
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS  
       [0018]    For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings in which:  
         [0019]    [0019]FIG. 1 is a perspective view of a casing of an extendible and retractable lead according to one embodiment of the-present invention;  
         [0020]    [0020]FIG. 2 is a cross-sectional view of one half of the casing shown in FIG. 1 illustrating the internal components thereof;  
         [0021]    [0021]FIGS. 3 a ,  3   b  and  3   c  are respectively a side view, top plan view and perspective view of the trigger means contained in the casing shown in FIG. 1;  
         [0022]    [0022]FIG. 4 illustrates engagement of the trigger means with the reel of the lead; and  
         [0023]    [0023]FIG. 5 a ,  5   b  and  5   c  illustrate the movement of the trigger means between its locked and unlocked positions during operation of the lead shown in FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]    Referring to the accompanying drawings, an extendible and retractable lead according to one embodiment of the present invention is illustrated. The lead comprises a length of cord  2  and a casing  4 . The casing  4 , serving as the handle for the lead, contains the mechanism for enabling extension and retraction of the lead  2 . The cord may be attached by suitable means to a length of strapping or the entire length of the lead may comprise strapping (not shown). The casing is a plastics moulded component, for example being of polypropylene, and is comprised of two halves that may be secured together my suitable fixing means. A handle or hand grip  6  is provided within the casing by the provision of a large hole through the centre of the casing, an aperture  8  is provided at the front end thereof to enable unhindered movement of the cord or strapping between the interior and exterior of the casing (as illustrated by arrow A in FIG. 1) and a further aperture  10  is provided for passage of trigger means  12  that activates the mechanism for extension or retraction of the lead (see arrow B).  
         [0025]    FIGS.  2  to  4  of the accompanying drawings illustrate the internal components of the casing that enable controlled extension and retraction of the lead. The components are housed within their own compartments formed by the internal profile of the moulded casing. A reel  14  having a central bore  15  is mounted on a pivot  16  that is formed integrally with one half of the casing  4  and a length of cord or strapping is wound around the reel, the free end of which extends through the aperture  8 . The top and bottom of the reel are provided with parallel flanges  9  extending substantially perpendicularly from the reel around the periphery thereof which enclose the cord or strapping. The outwardly facing surfaces of the flanges are provided with spaced apart ribs  16  formed integrally therewith (see FIG. 4).  
         [0026]    The casing also houses a proportion of the trigger means  12  that is in the form of a hollow moulded component (see, in particular, FIGS. 3 a  to  3   c ). One half of the trigger means is generally cylindrical and is provided with a concave outer end profile  22  for receiving the thumb of the operator of the lead. This part of the trigger means extends through the aperture  10  to the exterior of the casing. The trigger means is also provided with two parallel side members  24 ,  26  that are each relieved of material throughout the centre of the length thereof to provide parallel slots  30  and the free end of each member is biased to provide an indentation  31 . The shaping of the end of each member corresponds to the end profile of the ribs  16  (see FIG. 4). The roof between the side members  24   26  is provided by a resiliently deformable latch in the form of a living hinge  32  that extends approximately three-quarters along the length of the side members. The hinged latch is generally T-shaped having a lever  34  extending from the centre of the trigger means with a cross member  36  extending perpendicularly across the end of the lever. The area of material that joins each side member to the latch is oblique to form shoulders  38  and the end of the lever where it joins the main body of the trigger means is thinned  28  to increase the flexibility of the latch. Additionally, a spring  40  is provided extending from the interior of the trigger means towards the free ends of the side members and is biased towards the interior of the trigger means by abutment means  41  formed as part of the moulded casing (see FIG. 3 a ).  
         [0027]    The orientation and movement of the trigger means, reel and spring is controlled by the particular moulding of the interior surface of the casing. The part of the casing for housing the reel is provided with a circular compartment, the sides thereof formed by raised areas or ridges  42  in the moulding and by the side walls of the casing. One half of the casing is provided with a pivot female member  16  moulded integrally therewith onto which the reel is placed, and the corresponding location in the other half of the casing is provided with a short male member (not shown) that engages with the female member when the device is fully assembled. Additionally, breaks in the side walls of the compartments are provided to produce a gap for passage of the trigger means and to provide the aperture  8  for passage of the cord or strapping.  
         [0028]    The particular configuration of the moulding provided in the region of the casing that houses the trigger means is important. The area through which the living hinge can move upon application of force to the trigger to overcome the biasing of the spring is provided with a series of guides  50   54  separated by a retainer  52 . The guides and retainer are again formed by the profile of the internal moulding of the casing. The retainer is substantially C-shaped having one set of guides  50  formed around one half thereof and a second set of guides formed around the opposing side thereof. The contours of the guides are substantially parallel to the contours of the retainer. However, the guides meet above the centre of the opening of the retainer to form an apex  56 . The same configuration of guides and retainer are provided in corresponding positions in both halves of the casing. Additionally, the interior of the casing has further raised members for guiding the passage of the side members (not shown).  
         [0029]    Operation of the trigger means to prevent movement of the reel can be accomplished in a single motion. FIG. 4 and FIGS. 5 a  to  5   c  demonstrate how this is achieved by means of the present invention. Pushing the trigger means inwardly forces the cross member  36  of the latch onto the outer side of the retainer  52  and through the first set of guides  50  (see FIG. 5 a ). Continued movement of the trigger in that direction causes the cross member to turn around the top of the retainer and become lodged within the recess of the retainer (see FIG. 5 b ). Retention of the cross member in the retainer automatically locks the trigger means in a forward position which causes the free end of the side members  24   26  to be locked in position against the ribs  16  of the reel (see FIG. 4) thereby preventing rotation of the reel. Pushing the trigger means a second time in exactly the same manner causes the cross member  36  to be forced out of the retainer but, due to the angle of the cross member and the retainer, is directed through the second set of guides to release the latch thereby completing a substantially circular motion (see FIG. 5 c ). This enables the trigger means to move backwards thereby freeing the side members from the reel to allow rotation thereof. The spring acting on the trigger means assists in this movement.  
         [0030]    Thus, the device of the present invention is operated by means of a single movement which pushes the trigger means against the reel to prevent movement thereof and simultaneously locks the trigger means in position. Further activation of the trigger in a similar forward motion releases the locking mechanism and frees the trigger from the reel. This is a far simpler mechanism than those previously available for operation of a retractable lead.  
         [0031]    It is to be appreciated that the features provided by the moulding of the casing could be provided as separate components that are secured in the appropriate positions in the casing.  
         [0032]    The cross member of the hinged latch is preferably angled obliquely with respect to the lever such that it lies substantially parallel with the entry to the guides. This assists in obtaining unhindered movement of the latch through the guide and the retainer. The retainer is substantially C-shaped such that the cross member is forced against a first region and then is forced around the roof of the retainer and back into the recess of the retainer where it sits until further force is applied to the trigger means. The feature of the apex between the guides assists in ensuring that the cross member moves from the retainer to the second set of guides rather than moving back into the first set of guides thereby providing smooth operation of the device.  
         [0033]    It is clear that the latch has to be made of a resiliently deformable material that enables it to flex slightly to bend around the guides. For example an acetyl material may be used. In contrast the other parts of the lead may be formed of a more rigid material.