Abstract:
A hook and jack handle assembly in which the hook is retained within the tubular jack handle during use of the assembly in operating a vehicle jack. To this end, a tubular end portion in a jack handle has inserted therein a hook-shaped end piece having a pre-formed indentation. The tubular wall of the jack handle is displaced within the pre-formed indentation such that the end piece is prevented from slipping out of the jack handle during use.

Description:
Pursuant to 37 C.F.R. § 1.78(a)(4), this application claims the benefit of and priority to prior filed co-pending Provisional Application Ser. No. 60/076,731, filed Mar. 4, 1998, which is expressly incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to vehicle jacks and, more particularly, to an improved handle for actuating such jacks. 
     Motor vehicles have traditionally been equipped with a spare wheel to use in the event that one of the tires became flat or disinflated. Along with a spare wheel, some means for raising the vehicle in order to change the wheel must be provided. This means of lifting the vehicle has usually been some form of vehicle jack. 
     Some vehicle jacks have heretofore been designed to be positioned underneath the vehicle, usually just to the inside of the tire to be changed and the designated lifting point is generally the axle or other nearby wheel support structure. These jacks may be either of a scissors-type or a telescoping-type and normally utilize a screw drive. In both cases, a rotary force is applied to an operator or coupling on the end of a screw drive to either raise or lower the vehicle depending upon whether the rotary motion is clockwise or counterclockwise. 
     To impart that rotary motion to the jack, a handle is attached to the jack spindle both, to transmit the rotary motion to the jack and, to help position the jack at the proper lifting location underneath the vehicle. The jack handle must be long enough to reach from the perimeter of the vehicle to the jack which is positioned underneath the vehicle while still allowing enough room for the operator to apply the rotary motion to the end of the handle remote from the jack. 
     Some of the current jack handles on the market have a solid metal end with a generally L-shaped tip or hook on one end of the jack handle. This hook is engaged with an operator on the base of the jack which allows the jack handle to be used to push and pull the jack to position it underneath the vehicle. Furthermore, the hook drivingly engages the jack operating coupling and transmits the necessary rotary motion and torque from the jack handle to the jack screw in order to lift the vehicle. 
     Referring to FIG. 1, to manufacture the hook and jack handle assembly, a hook  14  is formed in a first end  13  of a solid metal end piece  12  which has an opposite end  18  with a noncircular cross-section. The opposite end  18  of the end piece  12  is inserted into a tubular section  20  of the jack handle  22  and then held in place while a stake or crimp (not shown) is applied to the outer surface of the tubular section  20 . In theory, the crimp should simultaneously form mating depressions in both the tubing wall  16  and opposite end  18  of the end piece  12 , which should secure the end piece  12  to the end of the jack handle  22  and prevent the end piece  12  from separating from the jack handle  22  during normal use. 
     In practice, however, often, this is not what happens. As the crimp punch displaces the material in the tubing wall  16 , the tubing wall material is merely compressed and thinned out to form a notch  26  between the crimp punch and the end piece  12 , as shown in FIG.  1 . The tubing wall does not displace the adjoining material in the end piece  12  as one would expect. If the crimping force is increased with the intent of causing the punch to penetrate into the end piece material, the tubing wall  16  is often punched through as shown at notch  28  in FIG.  2 . Alternatively, only an extremely thin section of tube wall  16  is left in the depression formed in the end piece  12 , which will not adequately retain the end piece  12  in the jack handle  22  when forces such as an axial load are applied to the hook and jack handle assembly. 
     In order to meet the torque requirements placed on the hook and jack handle assembly, the tensile strength of the end piece  12  is greater than the tensile strength of the tubular section  20  of the jack handle  22 . This would account for the softer tubing wall  16  not being able to displace the harder end piece material. Also the thin tubing wall  16  presents a much less substantial structure than the solid end piece  12 . Thus, the tubing wall  16  is simply displaced by the punch instead of being able to work the material of the end piece  12 . 
     As a result of the tubing wall  16  not displacing the material in the end piece  12 , the minimal contact between the end piece  12  and tubing wall  16  at the crimp area creates a frictional force that temporarily holds the end piece  12  in place within the jack handle  22 . Once the jack handle is used, however, the forces applied to the hook  14  and jack handle  22  can cause the tubular section  20  to relax slightly, that is, to deflect or move, and the contact between the tubular section  20  and end piece  12  is lost. The end piece  12  with hook  14  can then be easily dislodged from the jack handle  22  when longitudinal forces apply an axial load, such as when the hook and jack handle assembly is used to pull the jack (not shown) from underneath the vehicle. 
     There is thus a need to provide a hook and jack handle assembly in which the hook will not unexpectedly separate from the jack handle during normal use of the vehicle jack. 
     SUMMARY OF THE INVENTION 
     The present invention provides a hook and jack handle assembly for use in operating vehicle jacks in which the hook is permanently retained within the tubular end portion of the jack handle such that the jack handle assembly operates more reliably over the useful life of the jack. To this end and in accordance with the principles of the present invention, there is provided an end piece with a hook at one end and a pre-formed notch or depression in the other end for inserting into the end of a tubular jack handle to form a hook and jack handle assembly for operating a vehicle jack. Upon crimping the tubular wall of the jack handle, the punch engages the tube wall and forms a crimp or indentation within and/or forced into contact with the pre-formed notch in the end piece. This results in a substantial thickness of the tubing wall being depressed into the notch in the end piece such as to prevent the end piece from being removed and not subject to being separated from the jack handle during its normal use. Thus, the jack handle assembly of the present invention has the advantages of being easier to use and more reliable over the life of the assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial side view of a hook and jack handle assembly in the prior art, partially broken away to show the effect of crimping; 
     FIG. 2 is a partial side view of a hook and jack handle assembly in the prior art, partially broken away to show the effect of crimping with a greater degree of crimp punch penetration than that in FIG. 1; 
     FIG. 3 is a partial side view of a pre-notched end piece of a hook and jack handle assembly in accordance with the principles of the present invention which is partially broken away to further show the effect of crimping with a square-end punch; 
     FIG. 4 is a partial side view of a pre-notched end piece of a hook and jack handle assembly in accordance with the principles of the present invention which is partially broken away to further show the effect of crimping with a round-end punch; and 
     FIG. 5 is a cross-sectional view taken along the  5 — 5  line of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIGS. 3 and 4, the present invention overcomes the problem of the end piece not deforming during crimping, which results in failure of the hook and jack handle assembly under an axial load, by preforming a notch or depression  10  in the solid metal end piece  12  prior to its assembly with a jack handle  22 . The first end  13  of end piece  12  has a formed tip, for example, a generally L-shaped tip, such that first end  13  forms a hook  14  , that is adapted to engage and transmit rotary motion from the end piece  12  to a rotatable coupling (not shown) in a vehicle lifting jack (not shown). The opposite end  18  of end piece  12  has a noncircular cross-sectional profile for insertion into a tubular section  20  at one end of jack handle  22  to form a hook and jack handle assembly. The notch  10  is formed into the opposite end  18  of end piece  12 . Tubular section  20  of jack handle  22  and the opposite end  18  of end piece  12  have a noncircular cross-section, such as shown in FIG.  5 . 
     After inserting opposite end  18  having the notch  10  into tubular section  20 , a crimp punch (not shown) then engages the tubing wall  16  in the tubular section  20  of jack handle  22  to displace a substantial thickness of the tubing wall material and to form a crimp or indentation  30 ,  30 ′ within the pre-formed notch  10  in the end piece  12 . As would be apparent to one skilled in the art, the extent to which the tubing wall  16  contacts one or both sidewalls and the bottom of the pre-formed notch  10  may vary depending on a number of manufacturing factors, including the depth of the pre-formed notch  10 , the particular tooling used to crimp the tubing wall  16 , and the force used for crimping. Full contact between the tubing wall  16  and the walls of the pre-formed notch  10  to form mating depressions is preferred to provide superior hook retention. It will be appreciated, however, that less than full contact with the notch walls or no contact at all within the pre-formed notch  10  may occur due to the particular manufacturing route and tooling employed, yet still provide retention of the end piece  12  in the jack handle  22  during its normal use in accordance with the principles of the present invention. 
     The crimp punch may be a square-end punch, that is, a punch with V-shaped sides that terminate with a flat end normal to the centerline of the punch. A square-end punch was used to form crimp  30  in FIG.  3 . Alternatively, a round-end punch may be used, such as that used to form crimp  30 ′ in FIG. 4. A round-end punch has tapering V-shaped sides that terminate with a radiused end or arc that blends into the sides. A crimp punch of any other suitable end shape may also be used. Better results are obtained using the round-end punch for crimping tubing wall  16  because the rounded edges allow more working of the tubing material without cutting or thinning the tubing walls. The same types of punches described for use in crimping the tubing wall  16  may also be used to form the pre-formed notch  10 . For example, a square-end punch was used to form the notch  10  in FIGS. 3 and 4. The notch  10  formed in the end piece  12  need not be of the same shape as the crimp  30 ′ formed in the tubing wall  16 , as shown in FIG.  4 . 
     The jack handles and end pieces or hooks used in the assembly of the present invention may be of varied shapes and sizes. The preferred embodiment consists of a non-circular end section of the jack handle with a non-circular cavity therethrough, such as a square or rectangular cavity, and a non-circular solid end piece. For example, FIG. 5 depicts a cross section taken along line  5 — 5  in FIG. 4 showing a square tubular section  20  with a square cavity filled by a square end piece  12 . 
     In use, hook  14  of the jack handle assembly is engaged with an operator or coupling on the end of a screw drive at the base of the vehicle jack, and a longitudinal force is applied to the jack handle  22  to push the jack underneath the vehicle. Once positioned at a proper lifting point, rotary force in one direction is applied to the jack handle  22  so as to impart the necessary rotary motion and torque to the screw drive to raise the vehicle. After the vehicle tire has been changed, a rotary force in the opposite direction is applied to lower the vehicle, and the jack handle  22  with hook  14  is used to pull the jack out from under the vehicle. During this procedure, the hook  14  on end piece  12  is securely retained within jack handle  22 . This procedure may be repeated again and again over the life of the jack, and the hook  14  will remain permanently retained with jack handle  22  due to the tubular wall  16  being locked into the pre-formed notch  10 . 
     While the invention has been illustrated by the description of one embodiment and while the embodiment has been described in considerable detail, there is no intention to restrict nor in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those who are skilled in the art. For example, the end piece and cavity within the tubular section may be of any shape, such as square, rectangular, triangular, etc. Furthermore, the remainder of the jack handle may be of any material or shape. 
     In the present invention, the tubular end of the jack handle is formed from the same tubular material used for the remainder of the jack handle. However, as will be appreciated, the tubular section may be made from square or hex stock and welded onto the end of the jack handle. The hook end piece may be secured to the tubular end section of the jack handle by any number of known crimping or staking processes. 
     Therefore, the invention in its broadest aspects is not limited to the specific details shown and described. Consequently, departures may be made from the details described herein without departing from the spirit and scope of the claims which follow.