Brakes – Internal-resistance motion retarder – Using a rotary-type fluid damper
Reexamination Certificate
2001-05-10
2004-05-04
Siconolfi, Robert A. (Department: 3683)
Brakes
Internal-resistance motion retarder
Using a rotary-type fluid damper
C188S322500, C188S290000, C482S063000
Reexamination Certificate
active
06729448
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotary damper capable of sliding a sliding portion constituted of an rotary member radially along a basement portion and capable of adjusting the magnitude of a torque generated, and to a rotary damper generating a torque by narrowing a clearance between the outer surface of an oscillation member oscillated by the force of more than the regular amount generated by the rotation of a drive shaft and the inner peripheral surface of a chamber.
2. Description of Prior Art
Hereto in the past, when an hanging door or the like which are left open are closed, there have been problems in that colliding sounds are generated and a door or a door frame is broken because the door collides with the door frame by an abrupt door closing operation. In order to prevent such an abrupt door closing operation, a variety of dampers for braking the door closing operation have been proposed.
For example, as shown in
FIG. 14
, Japanese Patent Laid-Open No. 8-93312 discloses a fluid friction resistance type braking device for use on a door closer which comprises a rotary drum
34
fixed to a braking shaft
33
, an adjustment screw
35
screwed to a base portion
31
A fixed to a lid body portion
31
B of a body of equipment
31
, a movable drum
36
screwed to this adjustment screw
35
and capable of moving along a groove
31
C of die lid body portion
31
B and one way clutch
37
transmitting a one way only rotational operation to the braking shaft
33
.
Moreover, as shown in
FIG. 15
, such a damper apparatus is mounted on a sliding door in such way that a pinion
13
attached to the braking shaft
33
is engaged with a rack
12
fixed to a guide rail member
11
of the door frame side. When the door closing operation is performed, the rotational operation of the pinion
13
is transmitted to the braking shaft
33
by the clutch
37
and the door closing operation is braked. On the other hand, when the door opening operation is performed, the transmission of the rotational operation of the pinion
13
to the braking shaft
33
is prevented by the clutch
37
.
However, such a damper apparatus is constituted in such a manner that, by moving the movable drum
36
axially inside the body of equipment
31
, the contact and slide area between the outer peripheral surface of the movable drum
36
and the inner peripheral surface of the rotary drum
34
is changed so as to adjust the magnitude of a generated torque. Accordingly, when the generated torque has to be adjusted low in the magnitude, it is necessary to minimize the contact and slide area of both the above described surf aces. In such a case, it is necessary to separate largely radial surfaces of the movable drum
36
and the rotary drum
34
. As a result, there was a disadvantage that it was impossible to make a length of a damper main body in the axial direction short.
Furthermore, in the case when a door is abruptly closed, very high load temporarily operates the door. However, since the magnitude of the torque generated by the damper apparatus is a fixed quantity, it is impossible to absorb the above described high load, and enough damper effect cannot be obtained. As a result, the door closing operation is not braked, the problem arises that the generation of colliding noises and the breakdown of the door due to collision of the door to a door frame or the like is not preventable.
BRIEF SUMMARY OF THE INVENTION
Object of the Invention
Hence, there has been a desire for a compact damper with a short radial length or a damper capable of absorbing an extremely high load which acts temporarily when the door is abruptly closed.
SUMMARY OF THE INVENTION
The rotary damper according to a first invention for solving the above described problem, wherein a housing with its inside provided with a chamber, a drive shaft with its base end side housed inside the chamber, a rotary member housed inside the above described chamber axially supported by the drive shaft and a viscous fluid filled inside the above described chamber are provided and a torque is generated by the rotation of the above described rotary member,
the rotary damper generating a torque by the rotation of the above described rotary member, wherein the above described rotary member is provided with a basement portion axially integrally rotatably supported by the above described drive shaft, a torque adjustor capable of making a relative movement by action of the external force of more than the regular amount while maintaining a fixed relationship with the above described drive shaft, a slide member arranged axially movably and having an outer surface complementary to a part of the inner peripheral surface of the above described chamber and a spring means for energizing the slide member against the above described torque adjustor, and
wherein, by relatively moving the above described torque adjustor against the above described drive shaft, the above described slide member is allowed to slide radially along the above described basement portion in such a manner as to change a radial clearance between the outer surface of the above described slide member and the inner peripheral surface of the above described chamber, thereby changing a rotary torque of the above described rotary member.
By allowing the slide member to slide along the base portion so as to control a radial clearance formed between its outer surface and inner peripheral surface, the torque generated based on the sheering resistance of the viscous fluid existing in this clearance can be changed and therefore no limitation is imposed in relation to the radial length of the damper main body.
The above described torque adjustor comprises an adjustment ring integrally rotatably attached to the above described rotary member and a cam member attached to the outer periphery of the adjustment ring, wherein the outer periphery of the above described adjustment ring and the inner periphery of a center hole of the above described cam member are engaged with a concave portion formed on the one and a convex portion on the other, wherein the concave portion and convex portion are constituted in such a manner that, when the external force of more than the regular amount acts on the above described cam member, the above described cam member is allowed to swing at the predetermined angle relatively against the above described adjustment ring and the above described drive shaft. In this way, the torque adjustor can be certainly arranged at the predetermined angle against the drive shaft.
By allowing the outer periphery of the cam member of the above described torque adjustor to take the shape of oval, the distance from the center of the cam member to each contact portion with the slide member and the cam member can be continuously displaced.
The above described cam member has a radial projection portion projected outside of the above described housing and provides an action portion for swinging the above described torque adjustor at the predetermined angle relatively against the above described drive shaft on the tip of the above described projection portion. In this way, the torque adjustor can be easily swung till the position of the predetermined angle.
The above described torque adjustor comprises the cam member attached integrally rotatably to the basement portion of the above described rotary member and an adjustment member engaged with the cam member, wherein the above described cam member has a cam surface comprising a slant surface on the outer periphery, a joining portion joined axially at one side with the above described rotary member and a wall portion formed axially at the other side, wherein the above described adjustment member has an action surface engaged with the wall portion of the above described cam member axially at an inner end portion, and wherein the above described cam surface and the above described action surface are constituted in such a manner that, when the external force of more than the regular amount acts on the above describe
Merchant & Gould P.C.
Siconolfi Robert A.
Tok Bearing Co., Ltd.
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