One-way damper

• US 4,697,673 A
• Filed: 12/22/1986
• Issued: 10/06/1987
• Est. Priority Date: 07/16/1984
• Status: Expired due to Fees

• Current Assignee: Nifco Incorporated
• Original Assignee: Nifco Incorporated
• Inventors: Omata, Nobuaki
• Primary Examiner(s): HALVOSA, GEORGE
• Application Number:
  US06/945,220
• Time in Patent Office: 288 Days
• Field of Search: 188/290, 188/291, 188/296, 188/322.5, 188/82.1, 188/381, 188/306, 188/271, 188/281, 16/52, 16/72, 16/82, 16/85, 192/12 BA, 192/58 B, 192/41.5, 267/155
• US Class Current: 188/291
• CPC Class Codes: E05F 3/14 with fluid brakes of the rotary type
• CPC Class Codes: E05Y 2201/21 Brakes
• CPC Class Codes: E05Y 2201/256 with pistons or vanes
• CPC Class Codes: E05Y 2201/266 rotary
• CPC Class Codes: E05Y 2800/00 Details, accessories and auxiliary operations not otherwise provided for
• CPC Class Codes: E05Y 2900/132 Doors
• CPC Class Codes: F16D 57/02 with blades or like members braked by the fluid
• CPC Class Codes: F16F 7/06 in a direction perpendicular or inclined to the axis of rotation F16F7/023 takes precedence
• CPC Class Codes: F16F 9/12 Devices with one or more rotary vanes turning in the fluid any throttling effect being immaterial, i.e. damping by viscous shear effect only F16F9/53 takes precedence; pivoting supports for apparatus or articles placed on stands or trestles F16M11/06
• CPC Class Codes: G11B 15/67507 Ejection damping means

Abstract

A one-way damper has a rotor which is provided with a braking disc at one of its ends. The braking disc is received in a housing of the damper and the housing is filled with oil. The other end of the rotor extends outward from the housing and has a gear loosely mounted thereon. The gear is engaged with a coil spring. When the gear rotates in one direction, the coil spring is reduced in diameter so that it grips the rotor, making it possible for the torque of the gear to be transmitted to the rotor through the coil spring. When the gear rotates in the other direction, the coil spring is expanded in diameter so that it does not grip the rotor, making it possible for the gear to turn freely. The one-way damper is used in association with a lid or door to damp one but not the other of the opening and closing operations.

Claims

1. A one-way type of a damper comprising:

a housing provided with a sleeve-like base element and a bottom wall said bottom wall having a centrally disposed frustoconical upward projection thereon and an upwardly facing surface outwardly of said projection;

a rotor which has an axle and a braking disc at one end of said axle, the disc being contained in said housing together with a damping oil, the other end of the axle extending outward from said housing, and having a gear mounted thereon for rotation relative thereto, said axle at said one end having a recess receiving said projection for centralizing said axle, said one end of said axle having an annular portion below said disc and substantially engaging said upwardly facing surface, said axle having a boss extending above said disc;

said housing including a cap with a central opening through which said axle extends, and a resilient diaphragm in said housing beneath said cap and substantially engaging said boss, said damping oil being disposed below said diaphragm on either side of said disc and in said recess;

said gear having an axial bore therethrough and a counter-bore therein, and a coil spring into which said axle of said rotor is inserted, said spring fitting within said counter-bore and snugly embracing and engaging said axle, one end portion of said coil spring being fixed to said gear, the coil spring being reduced in diameter when said gear rotates in one direction and being expanded in diameter when said gear rotates in the other direction;

whereby said gear transmits torque to said rotor through said coil spring when said gear rotates in said one direction but not when said gear rotates in said other direction.

2. The one-way type of the damper as set forth in claim 1, wherein:

said gear is provided with a radial and axially extending slot of limited circumferential extent and opening into said counter-bore, and wherein said coil spring is formed from a single spiral of wire one end of which is bent in the direction reverse to the winding direction of said coil spring and fitting snugly in said slot to fix said end of said spring to said gear.

3. The one-way type of the damper as set forth in claim 1, wherein:

said coil spring is formed from a double spiral winding which is formed from two halves of a wire material bent at its middle portion to form said two halves thereof, a bending portion of the double spiral winding being bent in the direction reverse to the winding direction of said double spiral winding.

4. The one-way type of the damper as set forth in claim 1, wherein:

said coil spring is formed from a two-stage winding of a wire material, which two-stage winding is formed from two halves of said wire material by winding each of said halves individually of the same hand into each stage winding of said two-stage winding and stacking the thus wound stages on each other, a bending end of said two-stage winding being bent in the direction reverse to the winding direction of said two-stage winding.