Undercarriage

• US 5,509,159 A
• Filed: 09/02/1994
• Issued: 04/23/1996
• Est. Priority Date: 01/04/1993
• Status: Expired due to Term

• Current Assignee: Ferno-Washington Incorporated
• Original Assignee: Ferno-Washington Incorporated
• Inventors: Du-Bois, Robert L.
• Primary Examiner(s): Milano, Michael J.
• Application Number:
  US08/296,813
• Time in Patent Office: 599 Days
• Field of Search: 5/627, 5/86.1, 5/611, 296/20, 248/188.6
• US Class Current: 5/627
• CPC Class Codes: A61G 1/013 foldable or collapsible A61G1/017 takes precedence
• CPC Class Codes: A61G 1/0212 2 pairs having wheels within a pair on the same position in longitudinal direction, e.g. on the same axis
• CPC Class Codes: A61G 1/0237 having at least one swivelling wheel, e.g. castors
• CPC Class Codes: A61G 1/0262 having loading wheels situated in the front during loading
• CPC Class Codes: A61G 1/0293 stretcher supports with wheels, e.g. used for stretchers without wheels stretcher supports without wheels A61G1/06
• CPC Class Codes: A61G 1/0562 independently foldable, i.e. at least part of the leg folding movement is not simultaneous

Abstract

An undercarriage, particularly for stretchers, which has multi-height adjustment and does not need to be manually raised or lowered by the attendant when being loaded into, or unloaded from, an ambulance. The undercarriage includes a rectangular support structure, a wheeled height adjustable framework having first and second pairs of collapsible legs, and a height actuating mechanism. The height actuating mechanism comprises one or more ties connected to the first and second pairs of legs and to the support structure which are retractable or extendable so as to extend or collapse the first and second pairs of legs to thereby adjust the height of the support structure.

Claims

1. An undercarriage comprising a support structure fitted to a height adjustable framework consisting of first and second pairs of collapsible legs, and an actuating means for adjusting the height of the support structure, wherein the actuating means comprises first and second flexible ties respectively connected to the first and second pairs of collapsible legs and to the support structure through the intermediary of first and second spools onto which said first and second flexible ties are respectively retractable, which first and second flexible ties are retractable or extendable so as to extend or collapse the first and second pairs of legs to thereby adjust the height of the support structure, and wherein each said spool is under spring tension so that the associated flexible tie is biased to wind onto that spool, each said spool having an associated ratchet mechanism to enable its associated flexible tie to be unwound from its spool when the associated ratchet mechanism is disengaged so that the support structure can be lowered.

2. An undercarriage as claimed in claim 1, wherein the height of the support structure is infinitely adjustable between the fully collapsed and fully extended position of the first and second pairs of collapsible legs.

3. An undercarriage as claimed in claim 2, wherein the maximum height to which the support structure is raised is adjustable by stop means which control the amount by which the tie means is retracted.

4. An undercarriage as claimed in claim 1, wherein said first and second flexible ties are respectively connected to the first and second pairs of collapsible legs through the intermediary of first and second cross-bars.

5. An undercarriage as claimed in claim 1, wherein the first and second flexible ties are belts.

6. An undercarriage as claimed in claim 3, wherein said stop means is interposed between the first or second pairs of collapsible legs and is manually relocatable between an infinite number of fixed positions to thereby control the amount by which the tie means is retracted.

7. An undercarriage as claimed in claim 1, in which the support structure is adapted to carry a patient stretcher.

8. An undercarriage comprising a support structure fitted to a height adjustable framework consisting of first and second pairs of collapsible legs, and an actuating means for adjusting the height of the support structure, wherein the actuating means comprises first and second flexible ties respectively connected to the first and second pairs of collapsible legs and to the support structure, which ties are retractable or extendable so as to extend or collapse the first and second pairs of legs to thereby adjust the height of the support structure;

wherein said support structure comprises two substantially parallel spaced beams interconnected by connector members, and wherein said first and second pairs of collapsible legs are angled downwardly from intermediate regions of each of said beams, said first pair of legs being interconnected and pivotally joined to fixed points on said respective beams and said second pair of legs being interconnected and pivotally joined to a first cross-bar extending between said beams, which first cross-bar is slidable with respect to two shafts one each of which extends adjacent and parallel to one of each said beams, there being provided a pair of first linkages which each pivotally connect an intermediate portion of each one of said first pair of legs to a second cross-bar slidable with respect to said shafts and a pair of second linkages which pivotally connect an intermediate portion of each one of said second pair of legs to a fixed point on the respective beams.

9. An undercarriage as claimed in claim 8, wherein said first and second pairs of legs are fitted with ground wheels at their extremities and the support structure is adapted to carry a stretcher.