|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||182/129 ; 182/108|
|발명자 / 주소|
|대리인 / 주소||
|인용정보||피인용 횟수 : 12 인용 특허 : 3|
A roller device for ladders which facilitates moving the ladder along a wall vertically to accommodate changes in the ladder's angular inclination thereagainst. The roller device has a pair of sleeves that are removably positioned over the respective top ends of the ladder's rails. Each of the sleeves has an internal rail stop and a wheel rotatably positioned on its respective ends. One of the sleeves has a wheel brake to prevent "roll back" of the ladder once it is positioned against the wall with the attached roller device.
[ We claim:] [1.] Roller devices for ladders that are removably positioned over the top of rail end portions respectively of the ladder to allow the ladder to be moved over a vertical support surface, said roller devices comprises; a main cross-sectionally rectangular tubular body member having oppositely disposed open ends, parallel flanges extending from one of said open ends of said tubular body members, wheel means rotatably supported between said flanges, a rail stop comprises; a pin extending through aligned oppositely disposed apertures in said tu...