Push cart

Information

  • Patent Grant
  • RE38436
  • Patent Number
    RE38,436
  • Date Filed
    Monday, February 11, 2002
    22 years ago
  • Date Issued
    Tuesday, February 24, 2004
    20 years ago
  • Inventors
  • Examiners
    • Johnson; Brian L.
    • Fischmann; Bryan
  • US Classifications
    Field of Search
    • US
    • 280 638
    • 280 35
    • 280 38
    • 280 39
    • 280 40
    • 280 641
    • 280 645
    • 280 646
    • 280 651
    • 280 652
    • 280 654
    • 280 6551
    • 280 4717
    • 280 4718
    • 280 4724
    • 280 4727
    • 280 4729
    • 280 47315
    • 280 42
    • 280 63
    • 280 655
  • International Classifications
    • B62B120
Abstract
A push cart comprisesincludes a main frame, a handle, a front support, two wheel frames, two wheels, and a retractable rod and a rear support , wherein the main frame has a pair of side rods connected with a pair of rods of the handle in a slidable manner, the center portion of the main frame is connected to each other, and the lower portion of the main frame hasis connected with athe wheel frameframes and a wheel respectivelythe wheels. The lower respective endsportion of the main frame areis connected with respective endssides of the front support which then meshes with the wheel frameframes. The respective lower ends of the handle are connected with one end of the retractable rod whereas the other end of the retractable rod is connected with the inner center portion of the front support, thus,support. Thus, by operating the handle, the retractable rod is linked to move which then links the front support and the wheel frame to retract or to expand.
Description




FIELD OF THE INVENTION




This invention relates to a push cart, and more particularly, to a cart which can be operated by the handle to retract or to expand a front support and aat least one wheel frame.




BACKGROUND OF THE INVENTION




In order to produce a compact easy to carrycompact, easy-


to


-


carry



push cart, various prior art carts arewere made in compact size, by folding each parts of a cart,cart; however, such design still possesses many defects. Later, a compact push cart was developed which comprises a handle that is foldable against the supporting rod and to link wheels to collapse inwardly or to expand inwardly,inwardly; however, the support will still be needed to operate manuallyretraction of different parts are operated separately.





OBJECT OF THE INVENTION





ThisIt is the primary object of the present invention to provide a push cart which is easy to operate.





It is another object of the present invention to provide a push cart which structure is more solid and more compact.




It is a further object of the present invention to provide a push cart which is less expensive to produce.











BRIEF DESCRIPTION OF THE DRAWINGS





The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawings, in which like reference numerals designate like elements and wherein:






FIG. 1

is a perspective view of the present invention;





FIG. 2

is an enlarged view of a snap plate of the present invention;





FIG. 3

is a side view similar toof

FIG. 2


when the push cart is in operation;






FIG. 4

is a rear perspective view of the present invention in a folded status;





FIG. 5

is a perspective view similar to

FIG. 4

with a support in opening status;





FIG. 6

is a perspective view of the present invention in partially operating status;





FIG. 7

is a is an enlarged view of circle A of

FIG. 6

;





FIG. 8

is a rear perspective view of the present invention in an open status; and





FIG. 9

is a side view of the present invention in an open status.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIG. 1

, a push cart of the present invention comprises a main frame


1


, a handle


2


, a front support


3


, two wheel frames


4


, two wheels


5


, a retractable rod


6


and a rear support


7


. The interconnected relations are such that, the main frame


1


has its upper respective sides slidably connected with the lower respective sides of the handle


2


, the middle portion of the main frame


1


is connected with the respective sides of the rear support


7


while the lower portion of the main frame


1


is connected to the wheel frame


4


which then connected with a pair of wheels


5


. The respective lowermost ends of the main frame


1


are connected with the respective ends of the front support


3


which then meshes with the wheel frame


4


. The center portion of the handle


2


is connected with one end of the retractable rod


6


which has its other end connected to the inner center portion of the front support


3


. By operating the handle


2


, the retractable rod


6


is linked to retract or to expand the front support


3


and the wheel frame


4


.




The main frame


1


comprises a U-shaped rod


11


, two fixtures


12


, two supporting rods


13


, two sockets


14


, a cross bar


15


and a pulling spring


16


. The lower ends of the U-shaped rod


11


are connected with one end of each fixture


12


, the other ends of the fixtures


12


are secured with the supporting rods


13


, respectively. Each supporting rods


13


has a pulling spring


16


which connects to a pin


121


, the U-shaped rod


11


has a pair of sockets


14


being connected to a cross bar


15


at its respective ends.




The handle


2


is a reversed U-shaped and comprises two sliding seats


21


, a cross bar


22


, a lock


23


, a torque spring


24


and a snap plate


25


. The handle


2


is inserted at its two ends to the sockets


14


of the main frame


1


and secured with two sliding seats


21


which are also inserted through the U-shaped rod


11


so that the main frame


1


and the handle


2


are slidable against each other. The two sliding seats


21


are interconnected by a cross bar


22


which includes a lock


23


at center, as shown in

FIGS. 2 and 3

. The lock


23


includes a tube


235


in horizontal position having extending upwardly and downwardly, a pair of plates from respective ends, theends. The downward end plate of the tube


235


has a through hole (not marked) and is secured to the upper portion of an outer tube


61


of the retractable rod


6


by a fixed pin


231


, the


231


. The upper plates of the tube


235



haveare formed with a stopper



232


and two holes


233


and


234


, the


234


. The torque spring


24


is formed with spiral coil and a pair of bars


241


extending from respective sides thereof and a reversed U-shaped snap ring


242


at center of the rod


241


, the


241


. The snap plate


25


has a slope surface


251


at its top portion and a recess


252


at the rear end thereof, thethereof. The snap plate


25


comprises a hole


254


at the respective lower sides, and a stopper


253


at the front position, theposition. The torque spring


24


is connected to the lock


23


by inserting a pin


241


through the hole


233


, and a pin


243


through hole


234


and the center of the torque spring


24


, the


24


. The snap plate


25


is buckled to the tube


235


of the lock


23


by the cross bar


22


with the snap ring


242


of the torque spring


24


seat in the recess


252


of the snap plate


25


, whereas the stoppers


232


and


253



will block each other when the snap plate



25


is pushed rearwardly to a predetermined angle.




The front support


3


is in a plate form havingand has a pair of hinges


31


extending upwardly from the respective ends, eachends. Each hinge


31


is formed by two horizontal plates


311


which are inserted by the lower end of the supporting rod


13


of the main frame


1


and secured by a pin


32


therein. Each hinge


31


has a plate


311



having formed with teeth



312


, and the front support


3


has a rib


33


at its bottom portion for the convenience of operating the cart when fully loaded.




The wheel frame


4



hasis connected to the wheel



5


and is connected to the lower end of the supporting rod


13


, the


13


. The wheel frame


4


has also teeth


41


corresponding to and meshesmeshing with the teeth


312



, by the meshing of the teeth



312


and


41


,such that when the front support


3


is making horizontal or vertical movement, the wheel frame


4


can be turned left or right in a horizontal direction.




The retractable rod


6


includes an outer tube


61


, an inner tube


62


, a stopper


63


and a C-snap ring


64


, whereas the inner tube


62


is slidably inserted in the outer tube


61


and has formed with a stopper


63


at the top portion, theportion. The stopper


63


has a larger outer diameter than the outer diameter of the inner tube


62


but smaller than the inner diameter of the outer tube


61


, a


61


. A C-shaped groove


631


is formed on the top of the stopper


63


, and the


63


. The outer tube


61


has an inwardly bulge portion


611


and athe C-snap ring


64



atengaged with the lower end of the inner tube



62



which is connected to the center front portion of the front support



3


.




The rear support


7


is a plate having connected with a locating bar


71


which center portion will be clipped by the C-snap ring


64


, the respective sides of the rear support


7


are secured to the pin


121


of the fixture


12


, and the pulling spring


16


has one end secured to the rear support


7


, whereas the other end of the pulling spring


16


is secured to the supporting rod


13


which lower end is secured by the pin


32


so that a retract force is applied on the rear support


7


.




To operate the present invention, as shown in

FIGS. 4 and 5

, push the handle


2



is pushed towards the main frame



1


to retractreduce the length, whenlength of the cart. When when the retractingpushing of the handle


2



has reached a certain degreeto a lowest position, the outer tube



61


and the inner tube


62



will retract simultaneously, uponsubstantially telescope with full length of each other. Upon the groove



631


of the stopper


63


of the inner tube


62



reachesinterlocks with the pin



231


of the lock


23


, a further pushing force will activate the retractable rod


6


to link the front support


3


to turn, whereas the teeth


312


of the hinge


31


mesh with the teeth


41








41


, that links the wheel frame


4


to retract and return into the main frame


1


.




On the other hand, to expand the cart, by pulling the handle


2


outwardly, the retractable rod


6


will extend too, as shown in FIG.


6


. When the outer tube


61


and the inner tube


62


have reached to their extremity, as shown in

FIG. 7

, the stopper


63


of the inner tube


62


will be stopped by the bulge portion


611


,


611


. By applying a continuous pulling force on the handle


2


at this moment, the retractable rod


6


will expand the front support


3


and the meshing of the teeth


312


and


41


will bring the wheel frame


4


to expand too, as shown in FIG.


1


. Furthermore, the pulling force of the handle


2


with respect to the main frame


1


,


1


causes the snap plate


25


of the lock


23



willto clip the cross bar



22


of the handle


2



that(



that



confines the handle



2


from retraction. Still Furthermoreretraction)


. Even more



, when the rear support



7


is in expand position, as shown in

FIGS. 8 and 9

, the respective ends pull the pulling spring


16


, and the locating bar


71


will be clipped by the C-snap ring


64


of the retractable rod


6


which prevents the rear support


7


from returning to its retractable position.





The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not limited to the particular embodiments disclosed. The embodiments described herein are illustrative rather than restrictive. Variations and changes may be made by one skilled in the art without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations or changes which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.




Claims
  • 1. A push cart comprising a main frame, a handle, a front support, two wheel frames, two wheels, and a retractable rod and a rear support , wherein said main frame having the respective sides connected to respective sides of said handle in a slidable manner, the center portion of said main frame being connected to respective sides of said rear support, thea lower portions of said main frame being connected to said wheel frames which thenare connected to said wheels, respectively, the lower ends of said main frame being connectedand to respective sides of said front support, Further, the respective sides of said front support comprising teeth, and said wheel frames having teeth corresponding to and meshing with said teeth of said front support, said handle having its respective ends connected to one end of said retractable rod, and the other end of said retractable rod being connected to thean inner center portion of said front support, thus,such that by operating said handle, linkingthereby engaging said retractable rod andwith said front support and said wheel frames to move simultaneously.
  • 2. The push cart as recited in claim 1, wherein said main frame comprising a U-shaped rod, two fixtures secured to the respectivea lower endsportion of said U-shaped rod, two supporting rods connected to said fixtures, respectively, two sockets, and a cross bar and two pulling springs, each said supporting rod having a torque spring which has one end secured to said supporting rod while the other end of said torque spring being secured to said rear support , each said fixture comprising a pin, and said sockets being connected to said U-shaped rod and having athe cross bar extending in between.
  • 3. The push cart, as recited in claim 1, wherein said handle shape likeis shaped as a reversed English letter U, comprisingand includes two sliding seats, a cross bar, a lock, a torque spring, and a snap plate, wherein tworespective ends of said handle are inserted into respective sockets of said main frame and secured with said sliding seats of said main frame respectively, said sliding seats are inserted through respective ends of said U-shaped rod, asaid cross bar beingis set between said sliding seats, and athe lock beingis set on said cross bar, said lock beingand connected to said torque spring and said snap plate, said snap plate having a slope surface .
  • 4. The push cart, as recited in claim 13, wherein said lock havinghas a stopper at a top end thereof, and said snap plate having ahas at least one stopper at itsa lower left andor right positions, respectivelythereof.
  • 5. The push cart, as recited in claim 1, wherein said front support havinghas a pair of hinges extending from the respective endssides thereof, and each hinge hinges thesaid front support to one lower ends of each saidof two supporting rods of the main frame, and each hinge havinghas teeth,meshing with corresponding teeth of said wheel frame hinged to the lower end of said supporting rod, and said wheel frame corresponding to said teeth of said rear support having formed with teeth for meshing togetherframes.
  • 6. The push cart, as recited in claim 1, wherein said retractable rod comprisingcomprises an outer tube, an inner tube, a stopper and a C-snap ring, whereas said inner tube beingis sleeved on said outer tube in an sliding manner, and said inner tube havinghas a stopper at itsa top end which comprisesthereof, the stopper has an outer diameter slightly larger than thean outer diameter of said inner tube and smaller than thean inner diameter of said outer tube, said stopper comprisingcomprises a C-shaped groove at itsa top end thereof, and said outer tube havinghas an inner bulge portion, said outer tube having aand the C-snap rigring at thea lower end and the lower end of said outer tube being connected to the center portion of said rear supportthereof.
  • 7. The push cart, as recited in claim 6, further comprising a rear support, wherein the lower portion of said main frame being connected to respective sides of said rear support, and a lower end of said inner tube is connected to the inner center portion of said front support.
  • 8. The push cart, as recited in claim 2, further comprising a rear support, wherein the center portion of said main frame being connected to respective sides of said rear support.
  • 9. The push cart as recited in claim 8, wherein said main frame further comprises two supporting rods, and each said supporting rods having a pulling spring which has one end secured to said supporting rod while the other end of said pulling spring being secured to said rear support.
  • 10. The push cart as recited in claim 1, wherein a length of the retractable rod substantially varies in order to retract the front support and the wheels to the main frame.
  • 11. The push cart as recited in claim 10, wherein the retractable rod includes tubes telescopingly engaged to vary the length of the retractable rod.
  • 12. The push cart as recited in claim 1, wherein the wheels are retracted by rotating about the main frame.
  • 13. A push cart comprising a handle, a main frame, a front support, two wheels, and a retracting means, wherein the main frame has a left side and a right side being connected to respective sides of the handle in a slidable manner, and a lower portion being connected to the front support and one side of each of the wheels such that the retracting means retracts the front support and the two wheels to the main frame simultaneously, and a length of the retracting means substantially varies in order to retract the front support and the two wheels to the main frame.
  • 14. The push cart according to claim 13, wherein the retracting means is connected to a upper portion of the main frame and an inner center portion of the front support so as to retract the front support and the wheels simultaneously.
  • 15. The push cart according to claim 14, wherein each of the wheels has a gear, and a right side and a left side of the front support each has at least one gear to mesh with the gear of each of the wheels respectively.
  • 16. The push cart according to claim 13, wherein the retracting means is shaped as a rod.
  • 17. The push cart according to claim 13, wherein said connection between at least two of the main frame, the front support, the wheels, and the retracting means is provided by at least one pair of meshing gears.
  • 18. The push cart according to claim 13, wherein said main frame includes a U-shaped rod, two fixtures secured to a lower portion of said U-shaped rod, two supporting rods connected to said fixtures respectively, two sockets, and a cross bar, each said fixture comprising a pin, and said sockets being connected to said U-shaped rod and having a cross bar extending in between.
  • 19. The push cart according to claim 13, wherein said handle has two ends connected to one end of said retracting means, and the other end of said retractable means is connected to an inner center portion of said front support such that said retractable means, said front support and said wheels are linked to move simultaneously by operating said handle.
  • 20. The push cart according to claim 13, wherein said handle is shaped like a reversed English letter U and has two sliding seats, and two ends of said handle are respectively inserted into two respective sockets of said main frame so as to be secured with the two sliding seats of the handle.
  • 21. The push cart according to claim 13, wherein said handle further has two sliding seats, a cross bar, a lock, a torque spring, and a snap plate, said sliding seats are inserted through respective ends of said U-shaped rod, said cross bar is set between said sliding seats, and said lock is set on said cross bar and connected to said torque spring and said snap plate.
  • 22. The push cart according to claim 21, wherein said lock having a stopper at a top end thereof, and said snap plate having at least one stopper at a lower left or right position thereof.
  • 23. The push cart according to claim 13, further comprising two wheel frames for connecting the wheels to the main frame, wherein said front support has a pair of hinges extending from respective sides thereof, and each hinge hinges said front support to one lower end of each of two supporting rods of the main frame, and each hinge has teeth meshing with corresponding teeth of each of said wheel frames.
  • 24. The push cart according to claim 13, wherein said retracting means comprises an outer tube, an inner tube, a stopper and a C-snap ring, wherein said inner tube being sleeved on said outer tube in a sliding manner, and said inner tube having a stopper at a top end thereof, the stopper has an outer diameter slightly larger than the outer diameter of said inner tube and smaller than the inner diameter of said outer tube, said stopper comprising a C-shaped groove at a top end thereof and said outer tube having an inner bulge portion and a C-snap ring at a lower end thereof.
  • 25. The push cart, as recited in claim 24, further comprises a rear support, wherein the lower portion of said main frame is connected to respective sides of said rear support, and a lower end of said inner tube is connected to an inner center portion of said front support.
  • 26. The push cart, as recited in claim 13, further comprising a rear support, wherein the right and left sides of said main frame are connected to respective sides of said rear support.
  • 27. The push cart as recited in claim 26, wherein said main frame further comprises two supporting rods, and each of said supporting rods has a pulling spring which has one end secured to said supporting rod while the other end of said pulling spring being secured to said rear support.
  • 28. The push cart as recited in claim 13, wherein the retracting means includes tubes telescopingly engaged to vary the length of the retracting means.
  • 29. The push cart as recited in claim 13, wherein the wheels are retracted by rotating about the main frame.
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Number Name Date Kind
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3659867 Curry May 1972 A
4315632 Taylor Feb 1982 A
4659096 Leimgruber Apr 1987 A
4754985 Im et al. Jul 1988 A
4917392 Ambasz Apr 1990 A
4993727 vom Braucke et al. Feb 1991 A
5127662 Spak Jul 1992 A
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5348325 Abrams Sep 1994 A
5439239 Su Aug 1995 A
5468005 Yang Nov 1995 A
5803471 DeMars et al. Sep 1998 A
5984327 Hsieh et al. Nov 1999 A
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Foreign Referenced Citations (9)
Number Date Country
217650 Oct 1941 CH
ZL98246528.9 Nov 1998 CN
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29714225 Nov 1997 DE
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0352515 Jan 1990 EP
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Non-Patent Literature Citations (1)
Entry
Decision 4 O 460/99 of the District Court of Dusseldorf in Germany (defendant was found infringing Braucke's patent EP0352515 by coping a model shown in DE29714225U1).
Divisions (1)
Number Date Country
Parent 09/141413 Aug 1998 US
Child 10/071827 US
Reissues (1)
Number Date Country
Parent 09/141413 Aug 1998 US
Child 10/071827 US