US 6,718,694 B2 · Drive nut assembly for a door operator

Abstract

The present invention teaches a powered door operator for passenger transit vehicles having a drive nut assembly engaging a door hanger bracket substantially connected to a door disposed within an aperture of the vehicle structure. Such drive nut further engaging a drive screw to move a door for covering and uncovering an aperture for ingress and egress of passengers in a wall of a transit vehicle upon rotation of the drive screw enabled by a rotary prime mover. The drive assembly comprises a housing having an internal cavity, at least one drive nut insert having a helix portion substantially identical to the drive screw helix and disposed within said internal cavity, and a retaining clip engaging said at least one drive nut insert for substantial retainment thereof. Retaining clip further provides for simple replacement of such at least one drive nut insert during maintenance cycles thereby substantially eliminating periodic lubrication generally employed with powered door operators of the prior art.

Claims28

Dependent claims

A drive nut assembly engaged with a drive screw in order to be driven thereby in a linear direction upon rotation of said drive screw by a prime mover, said drive nut assembly comprising:

(a) a drive nut housing having a cavity disposed therein;
(b) at least one drive nut insert disposed within said cavity, said at least one drive nut insert substantially engaging a threaded helix of said drive screw for transferring rotary motion of said drive screw to said drive nut assembly;
(c) a means engageable with said at least one drive nut insert for substantially retaining said at least one drive nut insert within said cavity disposed within said drive nut housing;
(d) a means engageable with said prime mover for transferring a force generated by said prime mover to a drive linkage;
(e) a means engageable with said drive nut assembly for substantially minimizing backlash within said drive nut assembly;
(f) a means engageable with said drive screw and said at least one drive nut insert for compensating for thermal expansion and contraction of said at least one drive nut insert without binding with said drive screw during door motion;
(g) a means engageable with said at least one drive nut insert for substantially minimizing rotation of said at least one drive nut insert within said cavity disposed within said drive nut housing;
and
(h) a means engageable with said drive screw for substantially eliminating external lubrication of said drive screw.

6 more elements

A powered door operator substantially attached to a door for moving said door to cover and uncover an aperture of a transit passenger vehicle, said door operator comprising:

(a) a prime mover;
(b) a drive screw attached to said prime mover;
(c) a drive nut assembly engaged with a drive screw in order to be driven thereby in a linear direction upon rotation of said drive screw enabled by said prime mover;
(d) a door hanger bracket assembly collared around a drive rod, said door hanger bracket assembly connected to said door for driving said door in a drive direction upon rotation of said drive screw, said drive screw being aligned substantially parallel to such drive direction, said door hanger bracket assembly providing rotational constraint in order to prevent a drive nut from rotating about an axis of said drive screw, said door hanger bracket assembly, further providing linear constraint of said drive nut along such axis of said drive screw between said drive nut and such driven component so that rotation of said drive screw causing motion of said drive nut parallel to such axis of said drive screw causes movement of said driven component parallel to such drive direction;
(e) a means compensating for wear producing loads caused by deflection and bending of a drive rod;
and
(f) a means for compensating for shock and vibration during door motion.

4 more elements

Dependencies are inferred from the claim text.

Drive nut assembly for a door operator

Life of this patent

Drive nut assembly for a door operator

Life of this patent

Abstract

Claims28