Telescopic and folding frame assembly for a golf cart
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to a golf cart for carrying a golf bag with clubs and relates more specifically to a telescopic and folding frame assembly for a golf cart. 
     A known golf cart, as shown in FIG. 1, mainly has a frame member of rectangular configuration, two golf bag cradles mounted on the frame member at two opposite locations for carrying a golf bag with clubs, a bracket mounted on the frame member at a mid portion thereof to hold a pair of ground supporting wheels by two side beams, a frame bar having a front end terminated into a hand grip and a rear end hinged to a front end of the frame member by a hinge means, a locking plate pivotably mounted on the frame bar adjacent to its rear end for locking the frame bar to a front end of the frame member in the operative position, and a pair of links pivotably connected between the rear end of the frame bar and the side beams at mid portions thereof. The locking plate has two retaining notches on two opposite side walls thereof and an unitary hand plate. By turning the hand plate with the hand, the locking plate is alternatively moved into the locking position with the two side pegs on the frame member respectively retained in the retaining notches for permitting the frame bar to be locked in the operative position, or the unlocking position with the two side pegs on the frame member released from the retaining notches for permitting the frame bar to be collapsed and closely attached to the frame member side by side. It is found that the locking plate may become loosely connected to the side pegs on the frame member after long use, causing a noise to be produce upon moving of the golf cart. Furthermore, it is difficult to lock the locking plate on the side pegs. 
     There is another structure of telescopic and collapsible golf cart disclosed in U.S. Pat. No. Re.33,939, which is generally comprised of a longitudinal frame member including a first section, a second section and a third section terminating in a handle and telescopically receivable within a hollow inner space of the second section; a base frame pivotably connected to the first section; a bracket secured to the first section; a pair of bag cradles secured to the first and second sections; a hinge means pivotably and laterally interconnecting the first section to the second section; a link member pivotally interconnecting the bracket to the hinge means; and second lock means for selectively locking the third section in a desired telescopic position with respect to the second section. In operation, the first section and the second section can be joined in aligned position through the engagement of male and female couplers and further locked in position by means of a lock member of the hinge means. On the contrary, the arm of the lock member can be swung counterclockwise to release a catch frame out of a hook on the bracket means, thereby permitting the second section to be swung counterclockwise into a position parallel to the first section. This operation procedure is complicated. Because this structure of telescopic and collapsible golf cart consists of a great number of parts, its assembly process is complicated, and its manufacturing cost is high. Still another disadvantage of this structure of a telescopic and collapsible golf cart is that most parts of the golf cart may rust away easily because they are made from iron or rigid metal materials. 
     It is therefore an object of the present invention to provide a telescopic and folding frame assembly for a golf cart which can be conveniently folded up into the collapsed condition or set up into the operative condition. It is another object of the present invention to provide a telescopic and folding frame assembly for a golf cart which can be firmly locked in position to eliminate noises as the golf cart is moved. With these objects in view, the locking plate in the folding frame bar mounting structure according to the preferred embodiment of the present invention is pivotably mounted on the frame bar and retained by a spring and stopped from forward swinging by a stop plate. The locking plate has a back opening on a back wall thereof and a guide slope on a top wall thereof for guiding a front connecting rod on the frame member into or out of a lock hole defined within the locking plate for permitting the front connecting rod of the frame member to be retained by the locking plate in the locking position or released from the locking plate. The back opening on the locking plate allows the locking plate to be turned backwards from the locking position to the unlocking position for permitting the front connecting rod of the frame member to be inserted into the lock hole of the locking plate or released therefrom. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a folding frame assembly for a golf cart according to the prior art. 
     FIG. 2 is a perspective elevational view of the golf cart according to FIG. 1. 
     FIG. 3 is a side view of a telescopic and collapsible golf cart as disclosed in U.S. Pat. No. Re. 33,93 
     FIG. 4A, 4B, and 4C illustrate the structure and operation of the collapsible frame of the telescopic and collapsible golf cart of FIG. 3. 
     FIG. 5 is a perspective elevational view of a telescopic and folding frame assembly for a golf cart according to the present invention. 
     FIG. 6 is a side view of the folding frame bar mounting structure of the telescopic and folding frame assembly of FIG. 5 showing the front connecting rod of the frame member moved out of the locking plate on the elongated frame bar. 
     FIGS. 7A and 7B illustrate the operation of the present invention to fold up the folding frame mounting structure. 
     FIG. 8 illustrates the folding frame bar mounting structure of FIG. 6 locked in the operative position. 
     FIG. 9 is a perspective exploded view of the telescopic drag bar mounting structure of the telescopic and folding frame assembly of FIG. 5. 
     FIGS. 10A and 10B illustrate the operation of the present invention to adjust the position of the drag bar. 
     FIG. 11 is a sectional end view illustrating the connection of the two opposite mounting shells of the mounting device of the telescopic drag bar mounting structure. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 5 through 11, a folding frame assembly for a golf cart as constructed in accordance with the present invention is generally comprised of a folding frame bar mounting structure and a telescopic drag bar mounting structure. 
     Referring to FIGS. 9, 10 and 11, the telescopic drag bar mounting structure is generally comprised of a mounting device 1, a swinging block 2, a positioning member 3, an adjusting device 4, a drag bar 5 and a frame bar 6. The mounting device 1 is comprised of two opposite mounting shells 11, 12 and a plurality of fastening elements 13. The two opposite mounting shells 11, 12 comprise each an unitary, rectangular connecting portion 111 or 121 vertically extending downward from a substantially U-shaped holder portion 110 or 120 for connecting a frame bar 6 which is a part of the frame of a golf cart to which the drag bar of the present invention is secured. A plurality of mounting holes 112 or 122 are made on the connecting portion 111 or 121 of each of the two opposite mounting shells 11, 12 so that corresponding quantity of fastening elements 13 can be inserted therethrough to secure the two opposite mounting shells 11, 12 together. An unitary pin 16 extends from the inner wall of the connecting portion 111 or 121 of each mounting shell 11 or 12 for fastening in the frame bar 6. The holder portion 110, 120 of the two opposite mounting shells 11, 12 have each a notch 113 or 123 on its topmost edge, and a transversely curved, raised strip 14, a circular guide position 117, a rectangular hole 15 and a plurality of radial, convex strips 118 on its inner wall. The swinging block 2 is a substantially elongated block unitarily made of resilient plastic material through shape molding process having a key hole 22 vertically and laterally piercing therethrough, a guide post hole 116 transversely piercing therethrough at a lower position, a pivot hole 220 transversely piercing therethrough at a higher position near one lateral side, two curved grooves 21 transversely made on its two opposite side walls, and a plurality of concave strips 119 radially made on its two opposite side walls and respectively intersecting with the two curved grooves 21. The two curved grooves 21 are made in width slightly wider than the thickness of the transversely curved, raised strips 14 of the two opposite mounting shells 11,12. The positioning member 3 comprises a tubular body having a conical bottom end 33, a rectangular flange 32 and a rivet hole 31. After the swinging block 2 is mounted on the drag bar 5, the positioning member 3 is inserted in the drag bar 5 and fixedly secured therein by means of a rivet 531 which is fastened in the drag bar 5 through a rivet hole 31. The adjusting device 4 is comprised of a swivel knob 41 and a screw rod 42. The screw 42 is inserted from the rectangular hole 15 of a first mounting shell 11 or 12 through the pivot hole 220 of the swinging block 2 and the rectangular hole 15 of the other mounting shell 11 or 12 to connect with the swivel knob 41. During the fastening of the adjusting device 4, a washer 7 is mounted on the screw rod 42 to reduce possible wearing problem. By means of the control of the adjusting device 4, the swinging block 2 can be firmly squeezed or released so that the positioning of the drag bar 5 inside the two holder portions 110, 120 of the two opposite mounting shells 11, 12 and relative to the frame bar 6 can be conveniently adjusted. By means of the control of the swivel knob 41, the position of the drag bar 5 is adjusted. 
     Referring to FIGS. 5, 6, 7 and 8, the folding frame bar mounting structure is generally comprised of a frame member 8 having a front end terminated in a front connecting rod 82 and fastened with a locating plate 84 and a hinge means 81, and the elongated frame bar 6 of the aforesaid telescopic drag bar mounting structure having a top end coupled to the drag bar 5 and a bottom end fastened with a stop plate 63, a locking plate 64 and a connecting plate 65. The elongated frame bar 6 has also a scoreboard 62 mounted on a middle part thereof for recording the record of points made in a play. The connecting plate 65 on the elongated frame bar 6 is pivotably connected between two side arms 811 of the hinge means 81. The stop plate 63 has a top projection 631 extended from a rear end thereof, which has a top edge 6312 spaced from the casing 641 of the locking plate 64 by a space for inserting the front connecting rod 82 of the frame member 8 and two side edges 6311 on a top wall thereof spaced from the bottom projection 631 for fastening one end 661 of a spring 66. The spring 66 has an opposite end 662 fastened to a post 6411 inside the locking plate 64. The casing 641 of the locking plate 64 has two opposite sides 642 pivotably and bilaterally mounted on the elongated frame bar 6, a top wall 644 terminated into a guide slope 6441 through which the end edge 821 of the front connecting end 82 of the frame member 8 is smoothly moved into the space defined inside the casing 641 of the locking plate 64, and a front opening 6412 for allowing the casing 641 of the locking plate 64 to be swung on the elongated frame bar 6 within a predetermined angle. The connecting plate 65 has two bottom projections 651, 652 pivotably connected with two links 67. The frame member 8 has a first bag cradle 84 and a second bag cradle 86 on two opposite ends thereof for carrying a golf bag with clubs, and a bracket 83 on the middle to hold two ground supporting wheels (now shown) by two side beams 831. Each link 67 has one a front end 671 pivotably mounted on either bottom projections 651 or 652 on the connecting plate 65 and a rear end pivotably mounted on either side beam 831 at a middle portion thereof. 
     The folding frame bar can be conveniently folded up into the collapsed, non-operative condition by turning the locking plate 64 backwards on the elongated handle frame 6 from the front connecting rod 82 of the frame member 8 for permitting the front connecting rod 82 of the frame member 8 to be disconnected from the stop plate 63 and the locking plate 64 (see FIG. 6), and then turning the connecting plate 65 of the elongated frame bar 6 backwards on the hinge means 81 through 180° angle for permitting the links 67, the side beams 831 and the elongated frame bar 6 to be respectively collapsed and closely attached to the frame member 8 (see FIGS. 7A and 7B). The folding frame bar can also be conveniently opened from the collapsed, nonoperative condition into the operative condition and locked in position by turning the elongated frame bar 6 on the hinge means 81 in the reverse direction and permitting the end edge 821 of the front connecting rod 82 of the frame member 8 to be guided by the guide slope 6441 into the inside space of the casing 641 of the locking plate 64. Once the front connecting rod 82 of the frame member 8 was inserted into the inside space of the casing 641 of the locking plate 64, the locking plate 64 is automatically moved back to its former position by the spring 66 to lock the frame bar 6 to the frame member 8 in the operative position. Because of the arrangement of the stop plate 63 and the spring 66, the locking plate 64 is allowed to be swung on the elongated frame bar 6 within a predetermined angle. Because the links 67 are pivoted to the two bottom projections 651, 652 of the connecting plate 65 but not directly pivoted to the elongated frame bar 6, they can be conveniently collapsed when the elongated frame bar 6 is folded up. Because the elongated frame bar 6 is locked to the frame member 8 by the locking plate 64, moving the golf cart does not cause the elongated frame bar 6 to displace, and therefore no noise is produced while moving the golf cart. Because the stop plate 63, the locking plate 64, the connecting plate 65 and the hinge means 81 are respectively made from a plastic material through the process of injection molding, they do not rust away.