HWH has two basic styles of room extensions. They are simply the “A” style and “B” style rooms. This is not the actual mechanism name, HWH manufactures many different types of mechanisms. There are single-cylinder, dual cylinder, under floor slides, above floor slides, chain-driven mechanisms, etc.
No mater what kind of mechanism it is, it falls within one of two categories. If the room extends when the room cylinder extends, it is an “A” style room. The room will retract when the room cylinder retracts. If the room extends when the room cylinder retracts, it is a “B” style room. The room will retract when the room cylinder extends.
When doing repairs or diagnosing room issues, it may be important to know which style of the room, “A” or “B”, you are dealing with. The following descriptions will help you identify the style of room you are working on.
Important: Some mechanisms that use an HWH cylinder are not designed nor manufactured by HWH. Contact the machine manufacturer to obtain operating style information.
Rail type mechanisms, either single or multiple cylinder mechanisms, are “A” style rooms. This includes under the floor or in-floor mechanisms.
Single-cylinder above floor, hat or tube guided mechanisms, manufactured by HWH are “A” style rooms.
The single-cylinder cable-driven bed slide used by Four Winds is a “B” style room.
The vertical arm or scissors-type mechanisms are “A” style rooms. These mechanisms mount to the floor.
The four-cylinder rooms where the four-room cylinders attach directly to the outer wall of the vehicle are “A” style rooms.
The four-cylinder train drive rooms are “B” style rooms. Only Foretravel and Country Coach used these.
X-arm rooms are “B” style rooms. The x-arm mounts to the outer wall of the vehicle. The main arms are driven with a roller chain assembly and form a large X when the room is retracted.
All universal mechanisms are “B” style rooms. The universal rooms have a top and bottom roller chain assembly. There are no metal arms. Early universal mechanisms had the top chain closer to the middle of the room.
Lateral arm mechanisms mount directly to the outer wall of the vehicle. The mechanism cylinder drives a linkage assembly. There are two arms that attach to the room in which the linkage assembly moves in unison. If the main arms that attach to the room slant down, the room is an “A” style room. If the main arms that attach to the room slant up, the room is a “B” style room. To view the different room mechanisms go to “Room Extension Identification” under “Customer Support & Technical Service” at www.hwh.com