Single stage leadscrew cinch actuator

Patent metadata

Field	Value
Publication number	US-10465425-B2
Application number	US-201514841860-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Sep 3, 2014
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A door latch assembly for an automotive vehicle door includes a gearless cinch actuator. The cinch actuator includes an extensible housing member connected to a threaded rod by a nut. The extensible housing member is also connected to a cable for cinching the door. A motor rotates the threaded rod, which moves the extensible housing member between rest and cinched positions. The motor is connected to the threaded rod without the use of gears. An anti-friction agent, such as a combination of a PTFE-containing coating and PTFE-containing grease, is applied between the nut and the threaded rod. The materials and anti-friction agent used at the interface of the threaded rod and nut together provide a friction coefficient (μ) of about 0.045 or less.

First claim

What is claimed is:

1. A cinch actuator for a latch of a door to cinch the latch via movement by an actuator of the cinch actuator from a rest position, whereat the latch can be released to allow the door to be opened from a latched, closed position, to a fully cinched position, whereat the latch cannot be released to prevent the door from being opened from the latched, closed position, comprising:
a housing assembly;
a threaded rod extending along a load axis between a first end and a second end;
an extensible housing member surrounding said load axis;
a nut connecting said threaded rod to said extensible housing member, said nut being fixed against relative movement with said extensible housing member;
a motor connected to said first end of said threaded rod for rotating said threaded rod in a first direction which moves said extensible housing member along said load axis toward said motor from a rest position to a fully cinched position, and for rotating said threaded rod in a second direction which moves said extensible housing member along said load axis away from said motor and from the fully cinched position to the rest position; and
wherein said housing assembly and said extensible housing member defines a linear guide device for inhibiting rotational movement of said extensible housing member during rotation of said threaded rod as said extensible housing member moves along said load axis between the rest position and the fully cinched position.

2. The cinch actuator of claim 1 , further including an anti-friction agent including at least one of an anti-friction coating and anti-friction grease disposed between said nut and said threaded rod.

3. The cinch actuator of claim 2 , wherein at least one of said anti-friction coating and said anti-friction grease includes polytetrafluoroethylene (PTFE).

4. The cinch actuator of claim 3 , wherein said anti-friction agent includes a combination of said anti-friction coating and said anti-friction grease, and said anti-friction coating and said anti-friction grease each include polytetrafluoroethylene (PTFE).

5. The cinch actuator of claim 2 , wherein said nut includes at least one thread engaging said threaded rod, and wherein said anti-friction agent is applied to said at least one thread of said nut and said threaded rod.

6. The cinch actuator of claim 1 , wherein said threaded rod is formed of steel and said nut is formed of an acetal homopolymer resin.

7. The cinch actuator of claim 1 , wherein the co-efficient of friction at an interface between said threaded rod and said nut is about 0.045 or less.

8. The cinch actuator of claim 1 , wherein said motor is coupled to said threaded rod by an adapter and a counternut.

9. The cinch actuator of claim 1 , wherein said threaded rod has a thread pitch of about 0.5 mm or less; a thread diameter of about 3.0 mm or less, and a lead angle of about 3.4 degrees or higher.

10. The cinch actuator of claim 1 , wherein said extensible housing member and said nut are formed as of the same material.

11. The cinch actuator of claim 10 , wherein said material is plastic.

12. The cinch actuator of claim 1 wherein the housing assembly defining a chamber surrounding said threaded rod, at least a portion of said extensible housing member, and at least a portion of said motor.

13. The cinch actuator of claim 12 , wherein said linear guide is defined by said housing assembly including a top housing and a bottom housing fixed to one another to bound the chamber, wherein said extensible housing member includes a pair of outwardly extending ribs disposed on opposite sides of a ball which rolls in said chamber along a rail of said bottom housing within said chamber of said housing assembly.

14. The cinch actuator of claim 1 including a bearing and an adaptor connecting said first end of said threaded rod to said motor, wherein said adaptor is disposed between said bearing and said motor.

15. The cinch actuator of claim 14 wherein said housing assembly contains said threaded rod and surrounding at least a portion of said motor, wherein a shaft of said motor is press-fit into said adaptor and a ring formed of rubber is disposed between said motor and said housing assembly.

16. The cinch actuator of claim 1 including a position detector detecting when said extensible housing member is in the fully cinched position and communicating the fully cinched position to a control unit of the vehicle.

17. A door latch assembly for an automotive vehicle, comprising:
a housing assembly;
a door latch;
a cable connected to said door latch for cinching said door latch; and
a cinch actuator for pulling said cable to cinch said door latch, said cinch actuator including:
a threaded rod extending along a bad axis between a first end and a second end,
an extensible housing member surrounding said load axis and connected to said threaded rod, said extensible housing member connected to said cable,
a nut connecting said threaded rod to said extensible housing member, said nut being fixed against relative movement with said extensible member, and
a motor connected to said first end of said threaded rod for rotating said threaded rod in a first direction which moves said nut and said extensible housing member conjointly along said load axis toward said motor from a rest position, whereat the latch can be released to allow the door to be opened, to a fully cinched position, whereat the latch cannot be released to prevent the door from being opened from the latched, closed position, and for rotating said threaded rod in a second direction which moves said nut and said extensible housing member conjointly along said load axis away from said motor from the fully cinched position to the rest position, wherein said extensible housing member pulls said cable when moving from the rest position to the fully cinched position; and
wherein said housing assembly and said extensible housing member defines a linear guide device for inhibiting rotational movement of said extensible housing member during rotation of said threaded rod as said extensible housing member moves along said load axis between the rest position and the fully cinched position.

18. The door latch assembly of claim 17 , wherein said extensible housing member moves to the fully open position after pulling said cable.

19. The door latch assembly of claim 17 , wherein said extensible housing member includes a slot disposed adjacent a distal end, said cable includes a ferrule, and said ferrule is disposed in said slot of said extensible housing member.

20. A method of manufacturing a cinch actuator for a latch of a door to cinch the latch via movement by an actuator of the cinch actuator from a rest position, whereat the latch can be released to allow the door to be opened from a latched, closed position, to a fully cinched position, whereat the latch cannot be released to prevent the door from being opened from the latched, closed position, comprising the steps of:
providing a housing assembly;
providing a threaded rod extending along a load axis between a first end and a second end;
disposing an extensible housing member having a nut fixed against relative movement thereto around the load axis;
connecting the threaded rod to the extensible housing member via threaded engagement with the nut; and
connecting a motor to the first end of the threaded rod for rotating the threaded rod in a first direction which moves the nut and the extensible housing member along the load axis toward the motor from a rest

Assignees

• Magna Closures Inc

Inventors

• Clark John Edward
• Neyman Ilya
• Andraos Dani
• Mitchell John Robert Scott
• Distefano John
• Pailian Shant

Classifications

• E05B81/06 Primary

  using rotary motors · CPC title

• E05B81/64

  Monitoring or sensing, e.g. by using switches or sensors · CPC title

• E05B81/25

  Actuators mounted separately from the lock and controlling the lock functions through mechanical connections · CPC title

• Y10T292/14

  Ball · CPC title

• Y10T292/1021

  Motor · CPC title