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특허 상세정보

Weight-releasing ladder lockstep

국가/구분 United States(US) Patent 등록
국제특허분류(IPC7판) E06C-005/00   
미국특허분류(USC) 182/015; 182/017
출원번호 UP-0375147 (2006-03-14)
등록번호 US-7828115 (2010-11-25)
발명자 / 주소
출원인 / 주소
대리인 / 주소
    Rudoler & DeRosa LLC
인용정보 피인용 횟수 : 4  인용 특허 : 16

A novel lockstep mechanism for a rolling ladder is described. The weight-releasing ladder lockstep allows a ladder to be relocated on wheels but when a person climbs the ladder, the front wheels are automatically retracted and the ladder rests firmly with its front feet on the floor. When in the climbing (stationary) position the front wheels of the lockstep are retracted and the ladder rests on the lockstep's feet. When in the rolling position, the ladder is tilted slightly back on its rear wheels and the wheels of the lockstep are pushed down to allow ...


What is claimed is: 1. A weight actuated lockstep mechanism for a rolling ladder comprising: a lockstep base; a caster frame comprising casters, the caster frame being pivotally attached to the lockstep base; a shock link pivotally attached to the lockstep base and being held in place by a spring connecting the shock link to the lockstep base; a lockstep frame pivotally attached to the shock link at a fixed pivot point; a latch releasably connecting the lockstep frame and the caster frame. 2. The lockstep mechanism of claim 1 wherein the latch is a s...

이 특허에 인용된 특허 (16)

  1. Thurmond ; Jr. Elmer T. (Miami FL). Adjustable caster. USP1979094166516.
  2. Moffat William,AUX. Ladder. USP2001016179087.
  3. Vitols John R. (300 Oxford Avenue Brockville ; Ontario CAX K6V 3E2). Ladder support. USP1990054923050.
  4. Heger Siegfried,DEX ; Korbmacher Thomas,DEX. Large-capacity transport container. USP1998095806863.
  5. Guerette Marcel (Lachenaie CA). Mobile ladder. USP1977084044857.
  6. Gillis Donald G. ; Johnson Daniel. Mobile ladder stand. USP2000036039147.
  7. Gillis Donald G. ; Johnson Daniel. Mobile ladder stand. USP1999085941341.
  8. Swiderski Paul R.. Mobile warehouse ladder. USP1998085791434.
  9. Maupin, Michael Harrison; Maupin, Michael Shawn; Hill, Kenneth Roy. Retractable caster. USP2003016507975.
  10. Kendall Ray (Fort Worth TX). Retractable caster assembly having a lever in rolling engagement with a pressure plate. USP1983114417738.
  11. Anderson Milan B. (1225 Frontage Rd. - Space 7 Chula Vista CA 92011). Retractable wheel strut assembly. USP1986054588203.
  12. Gutierrez Ernest F. (P.O. Box 84 Bristol IL 60512). Safety ladder with caster assembly moveable positively to a retracted position. USP1977124063616.
  13. Bieszczad Todd Anthony. Safety mobile ladder stand. USP2001106305496.
  14. Heimbrock, Richard H.; Moore, William K.; Smith, Donald E.; Blyshak, William M.; Turner, Joanthan T.. Stretcher center wheel mechanism. USP2003016505359.
  15. Swiderski Paul R.. Support frame assembly. USP2000026026931.
  16. Young, David T.; Kaczor, Scott E.. Undercarriage for mobile ladders and platforms. USP2003026523640.