Electricity: motive power systems – Synchronous motor systems
Reexamination Certificate
2001-11-27
2004-02-24
Masih, Karen (Department: 2837)
Electricity: motive power systems
Synchronous motor systems
C318S696000, C318S632000, C318S611000, C318S758000, C318S449000
Reexamination Certificate
active
06696813
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to an open-loop mechanism for controlling the actuation of a slide out room used on mobile living quarters (such as a recreational vehicle).
DISCUSSION OF THE PRIOR ART
The width of mobile living quarters, such as recreational vehicles, is limited to that which may be accommodated for travel on the highways. Accordingly, when the mobile living quarters is parked for use, it is desirable to be able to expand the living quarters, to increase the available living area. Slide out rooms have become popular to effect expansion of the available living area of such mobile living quarters. These slide out rooms are retracted into the main living area when the vehicle is moved during travel, and extended from the main living quarters to provide additional living space when the mobile living quarters is parked for use. Slide out rooms are typically mounted on telescoping tubes which are mounted on the frame supporting the main living area, and are actuated by hydraulic rams, electric motors, or similar actuation devices. Typically, two or more such actuation devices are required. Slide out rooms are only semi-rigid. Furthermore, the two or more actuators are often not symmetrically located with respect to the slide out room, because placement of the actuators must accommodate wheel wells and other structural components of the mobile living quarters. It is thus desirable to synchronize operation of the actuators. It is also desirable to be able to control the “room out” and “room in” positions for the actuators to assure that the room is fully extended across its entire length when the room is extended for use, and to assure that it is fully retracted across its entire length when the room is retracted to permit the mobile living quarters to be moved. Failure to fully extend or fully retract the slide out room across its entire length may permit gaps to occur between the seals that seal the slide out room to the main living quarters, thus permitting moisture to leak into the unit. Failure to synchronize properly the motion of the actuators may cause undesirable deflection across the length of the room, again resulting in damage to the room or the vehicle, seal problems, and unsightly appearance of the room.
SUMMARY OF THE INVENTION
The present invention provides an open-loop synchronization system for a slide out room which synchronizes movement of the room during extension and retraction of the room without using position feedback from the extendable members supporting the room or the motors driving the extendable members. The motors used have known output characteristics which depend upon the motor input. The controller provides synchronized output signals to the motors to cause synchronized movement of the motors, and therefore synchronized movement of the extendable members. The “in” stop and “out” stop positions of the extendable members may be set during initialization of the system, and stored by the controller. Accordingly, by comparing the output signals provided to the motors during extension and retraction to the stored data corresponding to desired “in” and “out” stop positions, the system automatically stops the motors when the stop positions are reached, without feedback.
In another embodiment of the invention, stop devices which provide feedback to controller (or the operator) are used. In this embodiment, only open-loop synchronization of the motors is provided.
REFERENCES:
patent: 2831722 (1958-04-01), Hanson et al.
patent: 4157571 (1979-06-01), Shu
patent: 4254439 (1981-03-01), Fowler et al.
patent: 4651073 (1987-03-01), Shimizu et al.
patent: 4797831 (1989-01-01), Dressing et al.
patent: 4938160 (1990-07-01), Nakanura et al.
patent: 5295430 (1994-03-01), Dewald, Jr. et al.
patent: 5332276 (1994-07-01), Blodgett, Jr.
patent: 5800002 (1998-09-01), Tiedge et al.
patent: 5857733 (1999-01-01), Dewald, Jr. et al.
patent: 5915774 (1999-06-01), Tiedge
patent: 6052952 (2000-04-01), Frerichs et al.
patent: 6118945 (2000-09-01), Tanaka
patent: 6230078 (2001-05-01), Ruff
patent: 2136673 (1996-03-01), None
McManus Martin P.
McManus Patrick W.
Baker & Daniels
Masih Karen
VT Holdings II, Inc.
LandOfFree
Open-loop synchronizer for a slide out room does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Open-loop synchronizer for a slide out room, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Open-loop synchronizer for a slide out room will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3312429