초록 ▼

An adjustable cart, comprising in combination a base supported by wheels at least one of which is swiveled to allow cart steering travel, two frames carried by the base to pivot from active upright positions to stored down positions, one above the other, there being upright supports carried by the c

An adjustable cart, comprising in combination a base supported by wheels at least one of which is swiveled to allow cart steering travel, two frames carried by the base to pivot from active upright positions to stored down positions, one above the other, there being upright supports carried by the cart at or proximate cart corners, there being mechanism associated with the frame and certain of the supports to releasably lock the frames in upright extended positions relative to the supports in response to frame pivoting to upright positions, and there being lengthwise adjustable means, associated with each frame, whereby said mechanism is un-blocked to allow frame folding.

대표청구항 ▼

1. An adjustable cart, comprising in combination: a) a base supported by wheels at least one of which is swiveled to allow cart steering travel,b) two frames carried by the base to pivot from active upright positions to stored down positions, one above the other,c) there being upright supports carri

1. An adjustable cart, comprising in combination: a) a base supported by wheels at least one of which is swiveled to allow cart steering travel,b) two frames carried by the base to pivot from active upright positions to stored down positions, one above the other,c) there being upright supports carried by the cart at or proximate cart corners,d) there being mechanism associated with the frames and certain of the supports to releasably lock the frames in upright extended positions relative to the supports in response to frame pivoting to upright positions,e) there being lengthwise adjustable means, associated with each frame, whereby said mechanism is un-blocked to allow frame folding,f) said mechanism including cam surfaces on the supports and on the frame that are interengageable to displace lock elements toward locking positions,g) cam surfaces being interengageable as the frames pivot into upright position,h) said surfaces being relatively angled to elevate the frames during the final 20° of frame pivoting into upright positions. 2. The combination of claim 1 wherein the supports and frames define tubular surfaces for guiding frame lowering into said lowered position. 3. An adjustable cart, comprising in combination: a) a base supported by wheels at least one of which is swiveled to allow cart steering travel,b) two frames carried by the base to pivot from active upright positions to stored down positions, one above the other,c) there being upright supports carried by the cart at or proximate cart corners,d) there being mechanism associated with the frames and certain of the supports to releasably lock the frames in upright extended positions relative to the supports in response to frame pivoting to upright positions,e) there being lengthwise adjustable means, associated with each frame, whereby said mechanism is un-blocked to allow frame folding,f) said mechanism including cam surfaces on the supports and on the frame that are interengageable to displace lock elements toward locking positions,g) and wherein the cam surfaces and the supports are presented upwardly to engage cam surfaces on the frame for lifting the frame during the final 20° of frame pivoting into upright position. 4. The combination of claim 3 wherein there are retention notches associated with the supports to downwardly receive camming projections carried by the frame, and which define said camming surfaces on the frame. 5. The combination of claim 4 wherein said mechanism includes springs positioned to provide force acting to urge the projections downwardly into the notches. 6. The combination of claim 5 wherein said pivot operatively connects with said projections enabling frame pivoting, relative to the support or supports. 7. The combination of claim 6 wherein the pivot, said projection, and said spring are remain in alignment as the frame is pivoted. 8. The combination of claim 1 including an upper tray connected with upper extents of said frames, wherein the frames are locked in vertical orientation. 9. An adjustable cart, comprising in combination: a) a base supported by wheels at least one of which is swiveled to allow cart steering travel,b) two frames carried by the base to pivot from active upright positions to stored down positions, one above the other,c) there being upright supports carried by the cart at or proximate cart corners,d) there being mechanism associated with the frames and certain of the supports to releasably lock the frames in upright extended positions relative to the supports in response to frame pivoting to upright positions,e) here being lengthwise adjustable means,associated with each frame, whereby said mechanism is un-blocked to allow frame folding,f) there being an upper tray connected with upper extents of said frames, wherein the frames are locked in vertical orientation,g) and wherein the frames have vertically spaced connections, allowing upper tray connection to the frames at selected elevations. 10. The combination of claim 1 including ground engaging, vertically adjustable uprights proximate corners of the cart, and carried by the cart. 11. The combination of claim 10 wherein the cart has wheels, and said uprights have ground engaging feet at their lowermost ends, to project below the levels of the wheels for stationarily supporting the cart.