GB1588712A - Window adjustment mechanism - Google Patents

Description

(54) WINDOW ADJUSTMENT MECHANISM (71) We, H. R. TURNER (WIL LENHALL) LIMITED, of Holly Lane, Great Wyrley, Walsall, West Midlands WS6 6AJ, a British Company, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a window adjustment mechanism and its object is to provide such a mechanism with a drive transmission in the form of a rack and pinion device which has a self-locking action such that drive can be transmitted from the pinion to the rack but not vice versa.

According to the present invention we provide a window adjustment mechanism comprising guideways for mounting a window pane, a rack whose teeth extend arcuately about a first axis about which the rack is angularly displaceable, the rack being provided with an arm which is so connectible to the window pane that, in response to angular movement of the rack, the arm turns angularly and displaces the pane along said guideways, and a pinion device drivingly connected to the rack to effect angular displacement thereof and having a rotary axis which is generally parallel to said first axis, said pinion device being constrained for movement in a predetermined direction in such a way that its rotary axis can move towards and away from said first axis without the pinion device becoming demeshed from the rack, means being provided for biasing the pinion device towards said first axis, the drive elements of the pinion device being so arranged that, when the pinion device is at its position of closest approach to the first axis, adjacent intertoothed spaces on opposite sides of said rotary axis fully receive respective drive elements whereby, with the aid of said biasing means, the pinion device is held against being driven rotatably by the rack thereby resisting angular displacement of the rack and hence displacement of the window pane.

Typically, the mechanism of the invention may be used as a vehicle window winding mechanism for translating rotation of a handle or knob mounted on the internal face of the vehicle door into raising or lowering of the door window.

Preferably the drive elements of said pinion device have axes which are substantially co-planar with the rotational axis of the pinion device. The pinion device may be of various configurations; for example it may be in the form of a loop or ring with opposite sides of the loop constituting said drive elements, or it may be bifurcated with the limbs of the fork constituting said drive elements.

As used herein, the terms "tooth" and "teeth" are to be construed as covering any form of projection and not only gear-type teeth such as are used on rack and pinion devices. The teeth may, for example, comprise a series of pegs. Preferably to facilitate rotation of the pinion device and rolling of said drive elements with respect to the rack teeth, the bases of the intertooth spaces are conveniently of rounded concave shape, e.g.

generally semi-circular, and the teeth have arcuately convex flanks and rounded tips.

Conveniently also, said drive, elements are of circular cross-section - other crosssectional configurations are possible however.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a front elevation of a vehicle window winding mechanism; and Figure 2 is a sectional view of the mechanism shown in Figure 1.

The drawings show a window winding mechanism for a motor vehicle door having inner and outer panels 280 and 282 (see Figure 2). The window 283 is mounted for vertical adjustment in guide channels 284 and its lower edge has a slotted guide 286 for cooperation with the roller 288 provided on the end of a raising and lowering arm 290 which is pivoted at 292 and is provided with an arcuate toothed rack 294 concentric with pivot 292. The rack 294 is rotated by a pinion comprising a spindle 296 provided with a bifurcated portion whose limbs 298 or pegs 298a and b co-operate with the rack in the manner described below, the spindle being supported in a bearing bracket 300 having a slot 302 to allow the pinion to move radially inwardly and outwardly relative to the rack during turning of the pinion.

The spindle 296 extends through the inner door panel 280 and is connected to a handle 304 for turning the pinion. A spring (not shown) is provided to bias the pinion into full mesh with the rack. When the pinion is rotated, the rack 294 turns about pivot 292 and effects raising or lowering of the window, depending on the direction of turning of the pinion.

In contrast with the conventional type of pinion, the pinion does not rotate about a fixed axis because the spindle 296 is displaceable. The effect of rotating the pinion counterclockwise will be to drive the rack 18 clockwise. As the pinion rotates from the position shown, the upper peg 298a will begin to lift out of the intertooth space and the lower peg 298b will tend to bury itself further into its intertooth space; this is not however possible because the lower peg 298b is already fully engaged in its intertooth space.Consequently, the pinion as well as rotating with the spindle 296 will also tend to turn about the lower peg 298b causing the spindle 296 and slide 28 to travel to the left along slot 302 against the biassing of spnng (not shown), and the lower peg 298b will be drawn upwardly thereby imparting clockwise movement to the rack 294 via the tooth immediately above the lower peg. This will continue until the axes of the pegs 298a, b are in a radial horizontal plane with respect to pivot 292.

Further counterclockwise rotation of the pinion beyond this position will result in return movement of the spindle 296 under the action of the spring and the peg 298b will continue to move upwardly and impart clockwise movement to the rack until the pinion has been rotated through one complete revolution froní the position shown in Figure 1. As the first revolution nears completion, the peg 298a which, in the meantime, has been fully disengaged from the rack, will return into mesh and fully engage in the intertooth space below the peg 298b.

During the next clockwise revolution, the roles of the pegs are reversed and the peg 298a becomes instrumental in displacing the rack upwardly.

An important feature of this construction is that the axes of the pegs 298a, b lie in the same plane as the rotational axis of the pinion. Thus, when the pegs are fully engaged with the rack, they resist movement of the rack in either direction and the pinion remains fixed in position, i.e. no provision is necessary to prevent transmission of drive from the rack to the pinion because such movements are resisted by the pinion itself and angular movement of the rack can only be effected by rotating the pinion via the spindle. Another feature of this construction is its ability to lock itself in the sense that, if the user leaves the pinion in a position in which the axes of the pegs are in the radial horizontal plane, then the spring bias automatically causes the pinion to turn into a position in which the pegs are fully engaged with the rack.

Conveniently the pegs are circular and the base or root of each intertooth space of the rack is generally semi-circular and of substantially the same diameter as the pegs so that the pegs engage fully and snugly therein. Also the flanks of the teeth are conveniently convex and their apices are rounded to facilitate rolling of the pegs over the teeth as they mesh and demesh. It is to be understood however that the illustrated tooth and peg configurations are not essential and that various other configurations mav be employed.

WHAT WE CLAIM IS: 1. A window adjustment mechanism comprising guideways for mounting a window pane, a rack whose teeth extend arcuately about a first axis about which the rack is angularly displaceable, the rack being provided with an arm which is so connectible to the window pane that, in response to angular movement of the rack, the arm turns angularly and displaces the pane along said guideways, and a pinion device drivingly connected to the rack to effect angular displacement thereof and having a rotary axis which is generally parallel to said first axis, said pinion device being constrained for movement in a predetermined direction in such a way that its rotary axis can move towards and away from said first axis without the pinion device becoming demeshed from the rack, means being provided for biasing the pinion device towards said first axis, the drive elements of the pinion device being so arranged that, when the pinion device is at its position of closest approach to the first axis, adjacent intertoothed spaces on opposite sides of said rotary axis fully receive respective drive elements whereby, with the aid of said biasing means, the pinion device is held against being driven rotatably by the rack thereby resisting angular displacement of the rack and hence displacement of the window pane.

2. A mechanism as claimed in Claim 1 in which the drive elements of said pinion device have axies which are substantially co-planar with the rotational axis of the pinion device.

3. A mechanism as claimed in Claim 1 or 2 in which the pinion device is in the form of a loop or ring with opposite sides of the loop constituting said drive elements.

4. A mechanism as claimed in Claim 1

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. the manner described below, the spindle being supported in a bearing bracket 300 having a slot 302 to allow the pinion to move radially inwardly and outwardly relative to the rack during turning of the pinion. The spindle 296 extends through the inner door panel 280 and is connected to a handle 304 for turning the pinion. A spring (not shown) is provided to bias the pinion into full mesh with the rack. When the pinion is rotated, the rack 294 turns about pivot 292 and effects raising or lowering of the window, depending on the direction of turning of the pinion. In contrast with the conventional type of pinion, the pinion does not rotate about a fixed axis because the spindle 296 is displaceable. The effect of rotating the pinion counterclockwise will be to drive the rack 18 clockwise. As the pinion rotates from the position shown, the upper peg 298a will begin to lift out of the intertooth space and the lower peg 298b will tend to bury itself further into its intertooth space; this is not however possible because the lower peg 298b is already fully engaged in its intertooth space.Consequently, the pinion as well as rotating with the spindle 296 will also tend to turn about the lower peg 298b causing the spindle 296 and slide 28 to travel to the left along slot 302 against the biassing of spnng (not shown), and the lower peg 298b will be drawn upwardly thereby imparting clockwise movement to the rack 294 via the tooth immediately above the lower peg. This will continue until the axes of the pegs 298a, b are in a radial horizontal plane with respect to pivot 292. Further counterclockwise rotation of the pinion beyond this position will result in return movement of the spindle 296 under the action of the spring and the peg 298b will continue to move upwardly and impart clockwise movement to the rack until the pinion has been rotated through one complete revolution froní the position shown in Figure 1. As the first revolution nears completion, the peg 298a which, in the meantime, has been fully disengaged from the rack, will return into mesh and fully engage in the intertooth space below the peg 298b. During the next clockwise revolution, the roles of the pegs are reversed and the peg 298a becomes instrumental in displacing the rack upwardly. An important feature of this construction is that the axes of the pegs 298a, b lie in the same plane as the rotational axis of the pinion. Thus, when the pegs are fully engaged with the rack, they resist movement of the rack in either direction and the pinion remains fixed in position, i.e. no provision is necessary to prevent transmission of drive from the rack to the pinion because such movements are resisted by the pinion itself and angular movement of the rack can only be effected by rotating the pinion via the spindle. Another feature of this construction is its ability to lock itself in the sense that, if the user leaves the pinion in a position in which the axes of the pegs are in the radial horizontal plane, then the spring bias automatically causes the pinion to turn into a position in which the pegs are fully engaged with the rack. Conveniently the pegs are circular and the base or root of each intertooth space of the rack is generally semi-circular and of substantially the same diameter as the pegs so that the pegs engage fully and snugly therein. Also the flanks of the teeth are conveniently convex and their apices are rounded to facilitate rolling of the pegs over the teeth as they mesh and demesh. It is to be understood however that the illustrated tooth and peg configurations are not essential and that various other configurations mav be employed. WHAT WE CLAIM IS:

1. A window adjustment mechanism comprising guideways for mounting a window pane, a rack whose teeth extend arcuately about a first axis about which the rack is angularly displaceable, the rack being provided with an arm which is so connectible to the window pane that, in response to angular movement of the rack, the arm turns angularly and displaces the pane along said guideways, and a pinion device drivingly connected to the rack to effect angular displacement thereof and having a rotary axis which is generally parallel to said first axis, said pinion device being constrained for movement in a predetermined direction in such a way that its rotary axis can move towards and away from said first axis without the pinion device becoming demeshed from the rack, means being provided for biasing the pinion device towards said first axis, the drive elements of the pinion device being so arranged that, when the pinion device is at its position of closest approach to the first axis, adjacent intertoothed spaces on opposite sides of said rotary axis fully receive respective drive elements whereby, with the aid of said biasing means, the pinion device is held against being driven rotatably by the rack thereby resisting angular displacement of the rack and hence displacement of the window pane.

2. A mechanism as claimed in Claim 1 in which the drive elements of said pinion device have axies which are substantially co-planar with the rotational axis of the pinion device.

3. A mechanism as claimed in Claim 1 or 2 in which the pinion device is in the form of a loop or ring with opposite sides of the loop constituting said drive elements.

4. A mechanism as claimed in Claim 1

or 2 in which said pinion device is bifurcated with the limbs of the fork constituting said drive elements.

5. A window adjustment mechanism substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.