WO2006045159A1 - A means for preventing disengagement between a rack and pinion - Google Patents

A means for preventing disengagement between a rack and pinion Download PDF

Info

Publication number
WO2006045159A1
WO2006045159A1 PCT/AU2005/001673 AU2005001673W WO2006045159A1 WO 2006045159 A1 WO2006045159 A1 WO 2006045159A1 AU 2005001673 W AU2005001673 W AU 2005001673W WO 2006045159 A1 WO2006045159 A1 WO 2006045159A1
Authority
WO
WIPO (PCT)
Prior art keywords
rack
pinion
preventing disengagement
abutment
projection
Prior art date
Application number
PCT/AU2005/001673
Other languages
French (fr)
Inventor
Graham Davies
Jurgen Tilg
Daniel Flynn
Original Assignee
Schefenacker Vision Systems Australia Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2004906225A external-priority patent/AU2004906225A0/en
Application filed by Schefenacker Vision Systems Australia Pty Ltd filed Critical Schefenacker Vision Systems Australia Pty Ltd
Publication of WO2006045159A1 publication Critical patent/WO2006045159A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
    • F16H55/02—Toothed members; Worms
    • F16H55/26—Racks
    • F16H55/28—Special devices for taking up backlash
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R1/00—Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
    • B60R1/02—Rear-view mirror arrangements
    • B60R1/06—Rear-view mirror arrangements mounted on vehicle exterior
    • B60R1/062—Rear-view mirror arrangements mounted on vehicle exterior with remote control for adjusting position
    • B60R1/07—Rear-view mirror arrangements mounted on vehicle exterior with remote control for adjusting position by electrically powered actuators
    • B60R1/072—Rear-view mirror arrangements mounted on vehicle exterior with remote control for adjusting position by electrically powered actuators for adjusting the mirror relative to its housing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
    • F16H55/02—Toothed members; Worms
    • F16H55/17—Toothed wheels
    • F16H55/18—Special devices for taking up backlash

Definitions

  • This invention relates to a means used in association with a rack and pinion to prevent disengagement of the rack from the pinion.
  • it is designed to prevent gear teeth of the rack and pinion disengaging to the extent where the rack can move independently of the pinion.
  • a particular problem in this circumstance would be the disengagement and movement of the rack independently of the pinion. This will result in any position sensing control system of the mirror to be disrupted. Mirrors can be provided with position sensing controls to enable a mirror to be returned to a pre-set position. Clearly, if the rack were to jump the pinion gear, then that pre-set position would be lost.
  • the aim of the invention is to provide a solution to the problem associated with separation between the rack and pinion. It is a further aim to also provide an anti backlash system and to also provide an anti backlash system that works in conjunction with the means of preventing separation of the rack from the pinion.
  • the invention which is a means for preventing disengagement between a rack and a pinion, comprises an abutment means located behind said rack positioned to provide a clearance or sliding fit with a back surface of said rack when said rack is normally engaged with said pinion but which abuts against said back surface to prevent disengagement of said rack from said pinion when a separation force is applied.
  • the abutment surface comprises a projection located on the side of the rack which is opposite the pinion.
  • the projection is positioned so that it provides a running fit to allow normal operation of the rack but has a clearance which will prevent disengagement of the rack from the pinion to the extent where gear teeth between the rack and the pinion can not fully disengage to allow the rack to move independently of the pinion.
  • a biasing means is preferably provided that biases the rack into engagement with the pinion.
  • the biasing means provides a force, which prevents backlash between the rack and the pinion and also provides a damping force, which reduces movement between the rack and the pinion that might be caused due to vibration.
  • the invention will work with a number of configurations of rack and pinions.
  • the racks may be straight or curved and the invention will be equally suited to either design.
  • Figure 1 shows a plan view of a motor mechanism used to move a pair of racks that are attachable to a mirror
  • Figure 2 shows a part cross sectional view along the line A-A of Figure 1
  • Figure 3 shows an exploded view of some of the components shown in Figure 1.
  • Figure 1 shows a cross sectional view of a motor mechanism 10 used for moving the position of an external mirror of a motor vehicle.
  • the motor mechanism is normally mounted within the body of an externally mounted wing rear view mirror.
  • the motor mechanism 10 has an external plate [not drawn] to which the pair of jacks 11 are pivotally attached.
  • the plate in turn is pivotally mounted to the motor mechanism 10 and the jacks 11 attached to the external plate to provide adjustment of the plate about a horizontal and vertical axis. This provides the required adjustment for the mirror.
  • a pair of electric motors 12 are used to drive the gear train of the motor mechanism 10.
  • Each motor 12 has a first worm screw 13 that drives a first set of reduction gears [not drawn].
  • the first set of reduction gears comprise a gear wheel that engages the first worm 13 and a second worm then in turn engages gear wheel 14 that is associated with each motor 12.
  • the gear wheels 14 directly drive pinions 15 via a slipable friction clutch [not drawn] the pinion 15 in turn drives the rack 16 on the jack 11.
  • the jack 11 has a cylindrical head 17 that pivotally connects to the external plate.
  • the pivot point 18 of the external plate is positioned in relation to the cylindrical head 17 so that there is 90 degrees between the first cylindrical head 17 and the pivot point 18 and the second cylindrical head 17 and the pivot point 18. This provides a movement of the external plate about axes which are at 90 degrees with respect to one another. In other words, adjustment of a mirror about both a vertical and horizontal axis.
  • the slippage clutch between the gear wheel 14 and pinion 15 allows the pinion 15 to rotate with respect to gear wheel 14 once a predetermined load is applied. Consequently, when manual force is applied to the external plate, the aim is to have the rack rotate the pinion through release of the clutch. However, the force required to overcome the clutch is significant and, in some circumstances, there may be a tendency for the rack 16 to separate from the pinion 15. If this occurs, then the teeth of the rack 16 will slip across the teeth of the pinion 15 and the position of the jack 11 will obviously change in relation to the pinion 15.
  • abutment means comprising a projection 20 is positioned adjacent the back surface 21 of the jack 11 to limit the disengagement movement the rack 16.
  • the projection 20 is located opposite the pinion 15, and may comprise a portion of the housing, within which the assembly is located. In respect of a two piece housing, it may be located on the half that locates above the back surface 21.
  • a spring 24 is held within the motor mechanism 10 with portions that bear against both of the back surfaces 21 of the jacks 11. The ends of the spring 24 locate between the projection 20 and the back surface 21 of the jacks 11.
  • the spring 24 provides a biasing force against the back surface 21 which in turn urges the teeth of the rack 16 into engagement with the teeth of the pinion 15. This prevents any backlash and therefore the potential for vibration of the mirror that might occur if there was backlash. Sufficient clearance is provided between the projection 20 to allow placement of the ends of the spring 24 between projection 20 and the back surface 21 to provide a smooth or free running fit with the jack 11. The ends of the spring 24 will slide on the back surface 21 and little or no clearance is preferably provided between the projection 20 and the ends of the spring 24. This will ensure that the rack 16 can not disengage from the pinion 15 and will result in the clutch disengaging when manual force is applied.
  • the invention provides a simple means of ensuring smooth operation of a rack and pinion without disengagement.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Multimedia (AREA)
  • Rear-View Mirror Devices That Are Mounted On The Exterior Of The Vehicle (AREA)

Abstract

The invention is a means of preventing disengagement between a rack (16) and a pinion (15) that comprises an abutment means (20) located behind the rack (16) that is positioned to allow free movement of the rack (16). The rack has an elongate abutment surface (21) positioned adjacent the abutment means (20) that will abut against the abutment means (20) to prevent disengagement of the rack (16) from the pinion (15) when a separation force is applied to the rack (16). This prevents the rack (16) disengaging from the pinion (15) when the rack (16) is manually moved for example.

Description

A MEANS FOR PREVENTING DISENGAGEMENT BETWEEN A RACK AND PINION
This invention relates to a means used in association with a rack and pinion to prevent disengagement of the rack from the pinion. In particular, it is designed to prevent gear teeth of the rack and pinion disengaging to the extent where the rack can move independently of the pinion.
BACKGROUND OF THE INVENTION The invention will find numerous applications. However, for the ease of description, the invention will be described in respect of one particular application. That application is the use of a rack and pinion that is electrically driven where the rack adjusts the position of a mirror for a motor vehicle.
In this particular application, there is a need to design the mechanism to take into account the possible manual movement of a mirror. In this instance, the rack, which is pivotally attached with respect to the mirror surface, will be moved in relation to the pinion. The forces involved may cause the rack to move out of engagement with the pinion. This is particularly the case if the gear teeth on the rack and pinion are angled and act as a ramp surface. The resistance to rotation of a pinion may be greater than the separation force required to disengage the tooth of a rack from a pinion gear.
A particular problem in this circumstance would be the disengagement and movement of the rack independently of the pinion. This will result in any position sensing control system of the mirror to be disrupted. Mirrors can be provided with position sensing controls to enable a mirror to be returned to a pre-set position. Clearly, if the rack were to jump the pinion gear, then that pre-set position would be lost.
It is also important to prevent or minimise backlash between the rack and the pinion. This will minimise the tendency for the mirror to vibrate due to backlash or slack in the drive train. At the same time, any backlash prevention system needs to work in combination with the means of preventing disengagement between the rack and pinion.
Accordingly, the aim of the invention is to provide a solution to the problem associated with separation between the rack and pinion. It is a further aim to also provide an anti backlash system and to also provide an anti backlash system that works in conjunction with the means of preventing separation of the rack from the pinion.
SUMMARY OF THE INVENTION
In one aspect, the invention, which is a means for preventing disengagement between a rack and a pinion, comprises an abutment means located behind said rack positioned to provide a clearance or sliding fit with a back surface of said rack when said rack is normally engaged with said pinion but which abuts against said back surface to prevent disengagement of said rack from said pinion when a separation force is applied.
Preferably, the abutment surface comprises a projection located on the side of the rack which is opposite the pinion. The projection is positioned so that it provides a running fit to allow normal operation of the rack but has a clearance which will prevent disengagement of the rack from the pinion to the extent where gear teeth between the rack and the pinion can not fully disengage to allow the rack to move independently of the pinion.
A biasing means is preferably provided that biases the rack into engagement with the pinion. The biasing means provides a force, which prevents backlash between the rack and the pinion and also provides a damping force, which reduces movement between the rack and the pinion that might be caused due to vibration.
The invention will work with a number of configurations of rack and pinions. For example, the racks may be straight or curved and the invention will be equally suited to either design.
In order to fully understand the invention, a preferred embodiment will be described, but it should be realised that the invention is not to be restricted to the features of the embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiment of the invention is described in relation to its application for adjusting the position of an external mirror for a motor vehicle. In this embodiment,
Figure 1 shows a plan view of a motor mechanism used to move a pair of racks that are attachable to a mirror,
Figure 2 shows a part cross sectional view along the line A-A of Figure 1, and
Figure 3 shows an exploded view of some of the components shown in Figure 1. DETAILED DESCRIPTION
Figure 1 shows a cross sectional view of a motor mechanism 10 used for moving the position of an external mirror of a motor vehicle. The motor mechanism is normally mounted within the body of an externally mounted wing rear view mirror. The motor mechanism 10 has an external plate [not drawn] to which the pair of jacks 11 are pivotally attached. The plate in turn is pivotally mounted to the motor mechanism 10 and the jacks 11 attached to the external plate to provide adjustment of the plate about a horizontal and vertical axis. This provides the required adjustment for the mirror.
Referring to Figure 1, a pair of electric motors 12 are used to drive the gear train of the motor mechanism 10. Each motor 12 has a first worm screw 13 that drives a first set of reduction gears [not drawn]. The first set of reduction gears comprise a gear wheel that engages the first worm 13 and a second worm then in turn engages gear wheel 14 that is associated with each motor 12. The gear wheels 14 directly drive pinions 15 via a slipable friction clutch [not drawn] the pinion 15 in turn drives the rack 16 on the jack 11. The jack 11 has a cylindrical head 17 that pivotally connects to the external plate.
The pivot point 18 of the external plate is positioned in relation to the cylindrical head 17 so that there is 90 degrees between the first cylindrical head 17 and the pivot point 18 and the second cylindrical head 17 and the pivot point 18. This provides a movement of the external plate about axes which are at 90 degrees with respect to one another. In other words, adjustment of a mirror about both a vertical and horizontal axis.
The slippage clutch between the gear wheel 14 and pinion 15 allows the pinion 15 to rotate with respect to gear wheel 14 once a predetermined load is applied. Consequently, when manual force is applied to the external plate, the aim is to have the rack rotate the pinion through release of the clutch. However, the force required to overcome the clutch is significant and, in some circumstances, there may be a tendency for the rack 16 to separate from the pinion 15. If this occurs, then the teeth of the rack 16 will slip across the teeth of the pinion 15 and the position of the jack 11 will obviously change in relation to the pinion 15.
In this case, there will be obvious disruption to any position memory devices that are used in association with the electric motor. Also, the resultant noise produced is not desirable.
In order to overcome disengagement of the rack 16 from the pinion 15, abutment means comprising a projection 20 is positioned adjacent the back surface 21 of the jack 11 to limit the disengagement movement the rack 16. The projection 20 is located opposite the pinion 15, and may comprise a portion of the housing, within which the assembly is located. In respect of a two piece housing, it may be located on the half that locates above the back surface 21.
Further, a spring 24 is held within the motor mechanism 10 with portions that bear against both of the back surfaces 21 of the jacks 11. The ends of the spring 24 locate between the projection 20 and the back surface 21 of the jacks 11.
The spring 24 provides a biasing force against the back surface 21 which in turn urges the teeth of the rack 16 into engagement with the teeth of the pinion 15. This prevents any backlash and therefore the potential for vibration of the mirror that might occur if there was backlash. Sufficient clearance is provided between the projection 20 to allow placement of the ends of the spring 24 between projection 20 and the back surface 21 to provide a smooth or free running fit with the jack 11. The ends of the spring 24 will slide on the back surface 21 and little or no clearance is preferably provided between the projection 20 and the ends of the spring 24. This will ensure that the rack 16 can not disengage from the pinion 15 and will result in the clutch disengaging when manual force is applied.
As will be seen from above, the invention provides a simple means of ensuring smooth operation of a rack and pinion without disengagement.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:
1. Means for preventing disengagement between a rack and pinion comprising an abutment means located behind said rack positioned to allow free movement of said rack, and an elongate abutment surface on said rack positioned adjacent said abutment means that will abut against said abutment means to prevent disengagement of said rack from said pinion when a separation force is applied to said rack.
2. Means for preventing disengagement according to claim 1 wherein said abutment means comprises a projection.
3. Means for preventing disengagement according to claim 2 wherein said projection is positioned opposite to said pinion.
4. Means for preventing disengagement according to any one of the preceding claims wherein said elongate abutment surface comprises a planar surface behind the gear teeth of said rack.
5. Means for preventing disengagement according to any one of the preceding claims further comprising resilient biasing means acting on said rack to push said rack into engagement with said pinion.
6. Means for preventing disengagement according to claim 5 wherein said biasing means comprises a leaf spring.
7. Means for preventing disengagement according to claim 6 wherein said leaf spring extends along said elongate surface and is positioned between said projection and the rear surface of said rack.
8. Means for preventing disengagement according to any one of the preceding claims wherein said rack is curved.
9. Means for preventing disengagement of a rack and pinion according to any one of the preceding claims used in a mechanism for adjusting the position of a motor vehicle rear vision mirror.
10. Means for preventing disengagement between a rack and pinion substantially as herein described and with reference to the accompanying drawings.
PCT/AU2005/001673 2004-10-29 2005-10-31 A means for preventing disengagement between a rack and pinion WO2006045159A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2004906225 2004-10-29
AU2004906225A AU2004906225A0 (en) 2004-10-29 A means for preventing disengagement between a rack and pinion

Publications (1)

Publication Number Publication Date
WO2006045159A1 true WO2006045159A1 (en) 2006-05-04

Family

ID=36226749

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2005/001673 WO2006045159A1 (en) 2004-10-29 2005-10-31 A means for preventing disengagement between a rack and pinion

Country Status (1)

Country Link
WO (1) WO2006045159A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2017127A1 (en) * 2007-07-19 2009-01-21 Visiocorp Patents S.à.r.l. Device to adjust the orientation of a mirror of a motorcar
CN102817991A (en) * 2012-02-17 2012-12-12 常熟市迅达粉末冶金有限公司 Output gear for reflective mirror
DE112013007022B4 (en) * 2013-05-03 2020-02-13 Mci (Mirror Controls International) Netherlands B.V. Movement mechanism and wing mirror for a vehicle equipped with such a movement mechanism

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3914774A (en) * 1974-05-31 1975-10-21 Graphic Systems Inc Photo machine with rod and rack guided carriage
US4116538A (en) * 1977-01-10 1978-09-26 Industrie Koot B.V. Motor-car mirror adjustable about two perpendicular axes
US4281899A (en) * 1979-07-26 1981-08-04 Industrie Koot B.V. Adjusting device for motorcar mirrors
US5701211A (en) * 1995-03-31 1997-12-23 United Technologies Automotive Systems, Inc. Vehicle mirror adjustment gear train

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3914774A (en) * 1974-05-31 1975-10-21 Graphic Systems Inc Photo machine with rod and rack guided carriage
US4116538A (en) * 1977-01-10 1978-09-26 Industrie Koot B.V. Motor-car mirror adjustable about two perpendicular axes
US4281899A (en) * 1979-07-26 1981-08-04 Industrie Koot B.V. Adjusting device for motorcar mirrors
US5701211A (en) * 1995-03-31 1997-12-23 United Technologies Automotive Systems, Inc. Vehicle mirror adjustment gear train

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2017127A1 (en) * 2007-07-19 2009-01-21 Visiocorp Patents S.à.r.l. Device to adjust the orientation of a mirror of a motorcar
US8127641B2 (en) 2007-07-19 2012-03-06 Smr Patents S.A.R.L. Device to adjust the orientation of a mirror of a motorcar
CN102817991A (en) * 2012-02-17 2012-12-12 常熟市迅达粉末冶金有限公司 Output gear for reflective mirror
DE112013007022B4 (en) * 2013-05-03 2020-02-13 Mci (Mirror Controls International) Netherlands B.V. Movement mechanism and wing mirror for a vehicle equipped with such a movement mechanism

Similar Documents

Publication Publication Date Title
KR101761139B1 (en) Outside mirror device for vehicle
KR100396730B1 (en) Vehicle mirror adjustment gear train
EP1754630B1 (en) Lowering mechanism for the exterior rear-view mirrors of motor vehicles
US7322257B2 (en) Step down gear train for an adjusting device of an automotive vehicle seat
US8316737B2 (en) Electric clamping device for an adjustable motor vehicle steering column
EP2230131B1 (en) Foldable rear view mirror assembly for a vehicle
EP2543546A1 (en) Vehicle outside mirror device
EP1997682A1 (en) Vehicle outside mirror device
EP2457772A1 (en) Vehicle outside mirror device
US4518066A (en) Safety parking brake for automatic transmissions
KR20070022225A (en) Hinge actuator and method for adjusting two parts of a hinge actuator relative to each other
WO2006045159A1 (en) A means for preventing disengagement between a rack and pinion
NL2002145C (en) Drive unit for mirror adjustment mechanism.
US8960046B2 (en) Locking device for a vehicle steering system
EP2644453B1 (en) Vehicle outside mirror device
EP3625084B1 (en) Auto tilt clutch mechanism
KR20020010566A (en) A mirror rotation mechanism
CN116080744A (en) Adjustment drive for a motor-adjustable steering column and steering column for a motor vehicle
CN113795684B (en) Brake device and method for controlling a brake device
EP3223117B1 (en) Operation device and method for manufacturing the same
JP3425540B2 (en) Opening / closing control device for skylight
CN211698444U (en) Head-up display and car
JP4143474B2 (en) Automotive electronics
KR102205602B1 (en) Positioning Pin for Serration Bar Jointed Seat Motor of Car
EP3141430A1 (en) System for the rotation of a rear view mirror frame

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BW BY BZ CA CH CN CO CR CU CZ DK DM DZ EC EE EG ES FI GB GD GE GM HR HU ID IL IN IS JP KE KG KM KP KR KZ LC LK LR LS LT LU LV LY MD MG MK MN MW MX MZ NA NG NO NZ OM PG PH PL PT RO RU SC SD SG SK SL SM SY TJ TM TN TR TT TZ UG US UZ VC VN YU ZA ZM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GM KE LS MW MZ NA SD SZ TZ UG ZM ZW AM AZ BY KG MD RU TJ TM AT BE BG CH CY DE DK EE ES FI FR GB GR HU IE IS IT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 05799122

Country of ref document: EP

Kind code of ref document: A1