Door dampening mechanism having a non-rotatable vane

A damper for the door of a cassette housing in a cassette tape recorder is formed by unrotatably inserting a resisting member provided with radially extended vanes around a support shaft protuberating from a base plate and setting the resisting member within a cup-shaped rotary member thereby allowing the vanes to slide frictionally on the inner wall surface of the rotary member. This damper is mounted in the machine proper of the recorder by fastening the resisting member to the machine proper through the medium of the fitting member and pivotally attaching the door to the rotary member by utilization of a rack and pinion. The opening and closing motion of the door is braked by the frictional slide of the resisting member on the inner wall surface of the rotary member. Thus, the shocks and vibration produced by the opening and closing motion of the door are abated.

BACKGROUND OF THE INVENTION 
This invention relates to damper means for the door such as of a cassette 
housing in a cassette tape recorder, to be used for the purpose of abating 
the shocks produced in consequence of the opening and closing of the door. 
Generally in the conventional cassette tape recorder, the cassette housing 
is so constructed that the opening of the door thereof is effected by 
manipulating an ejector button thereby allowing the cassette housing to 
fly open by the resilient force of a spring, for example, and the closing 
thereof by just pushing the cassette housing down against the resilient 
force of the spring thereby allowing the cassette housing to snap into 
position. In the construction wherein the opening and closing of the door 
are effected by such means as a spring or a lever, for example, the door 
is destined to produce vibration and shock whenever it is opened and 
closed. At times, the impacts of the repeated opening and closing of the 
door have eventually reached the extent of producing adverse effects upon 
the delicate quality of the recorder. In the circumstance, there has 
recently been disseminated a practice of adopting damper means of some 
sort or other for use in the mechanism for opening and closing the door of 
the cassette housing in the cassette tape recorder. 
Dampers of various constructions have been proposed for this purpose. For 
example, Japanese Utility Model Laid-Open Publication No. 90116/1979 
discloses a door operating mechanism which comprises a cylinder rotatably 
mounted in the body of the recorder, a rod piston pivotally attached to 
the door of the cassette housing and encased together with a spring within 
the same cylinder, and a viscous substance contained within the cylinder 
for the purpose of abating the impact of the motion of door opening and 
closing; Japanese Utility Model Laid-Open Publication No. 52878/1980 
discloses a device wherein a braking rotator mounted on the pivotal shaft 
of the door and adapted to be expanded outwardly by the centrifugal force 
of the rotation of the shaft of the door is encased within a stationary 
drum, and at the time that the door is opened or closed, the braking 
rotator is allowed to expand and slide on the inner wall surface of the 
stationary drum and consequently apply brakes to the motion of the door 
opening or closing; and Japanese Utility Model Laid-Open Publication No. 
75805/1980 discloses a device wherein a braking member is encased within a 
cylinder fastened to the body of the recorder and an engaging shaft is 
interlocked with the braking member in such a manner that the shaft keeps 
an effectively meshed engagement with the braking member in one rotary 
direction thereof and an idle engagement therewith in the other rotary 
direction, whereby brakes are applied to the door when the door is opened 
and no brakes are applied when the door is closed. 
The conventional damper means including those cited above invariably use 
many component parts. These component parts tend to have complicate 
designs and, consequently, are difficult to fabricate and assemble. These 
damper means inevitably turn out to be expensive and susceptible to 
mechanical troubles during service. Thus, various faults have been found 
with the conventional damper means. 
SUMMARY OF THE INVENTION 
An object of this invention is to provide a damper means for the door which 
comprises a small number of component parts so simple in design as to 
permit easy fabrication and assembly and which continues to produce the 
required shock-absorbing effect stably for a long time. 
To accomplish the object described above according to the present 
invention, there is provided a damper means for the door which comprises a 
fitting member formed of a base plate and a support shaft protruding from 
the center of the base plate, a resisting member formed of a cylindrical 
shaft and vanes provided radially on the cylindrical shaft, and a 
cup-shaped rotary member provided on one flat face thereof with a toothed 
wheel. 
This damper means can be assembled simply by unrotatably attaching the 
resisting member to the support shaft of the fitting member and inserting 
into the rotary member the resisting member already fitted integrally into 
the fitting member in such a manner that the vanes of the resisting member 
frictionally slides on the inner wall surface of the rotary member. In the 
construction described above, the damper means of this invention comprises 
only three component parts of a synthetic resin very easy to assemble. 
The incorporation of this damper means into the cassette tape recorder is 
accomplished by fastening the fitting member of the damper means to the 
machine proper of the tape recorder and pivotally attaching the rotary 
member of the damper means to the machine proper by allowing the rack gear 
provided on the door of the cassette housing to be meshed with the toothed 
wheel of the rotary member. Once the damper means is thus set fast in the 
tape recorder, the opening or closing motion of the door of the cassette 
housing is braked by the frictional slide of the rotary member on the 
resisting member. Thus, the damper means provides effective abatement of 
the shock and vibration caused by the opening or closing motion of the 
door.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
This invention relates to a damper means of a simple construction, designed 
to abate the impact arising from the opening and closing motion of the 
door of the cassette housing in a cassette tape recorder. 
In FIG. 1, 1 denotes a cassette housing which is provided in the machine 
proper such as a cassette tape recorder, 2 a door attached freely openably 
to the opening of the cassette housing through the medium of hinges, and 3 
the damper means of the present invention provided therein for the purpose 
of abating the impacts causable during the opening or closing of the door. 
As illustrated in FIG. 5, the damper means 3 comprises a fitting member 4, 
a resisting member 5, and a rotary member 6. The fitting member 4 has a 
circular base plate 7 and a raised circular extension forming bearing 
surface 7a. Base plate 7 is provided on its peripheral surface with 
fitting pieces 8 and at the center of the circular extension with a 
vertically protuberating support shaft 9. From the peripheral portion of 
the base plate 7, three engaging claws 10 are raised parallel to the 
support shaft 9 as spaced equally in the circumferential direction so as 
to enclose the support shaft therein. The resisting member 5 has at the 
center thereof a bearing or hub 11 of a cylindrical shape and is provided 
on the peripheral surface of the bearing 11 with a multiplicity of vanes 
12 generally radially extended and equally spaced in the circumferential 
direction. The bore of the hub 11 has a diameter approximating the 
diameter of the support shaft 9 of the fitting member 4. This hub 11 is 
provided on the inner wall surface thereof with two grooves or slots 13 
diametrically opposed to each other and running parallel to the axial 
direction of the bearing. These grooves are formed so as to 
complimentarily mate with the two axially extending ribs or ridges 14 
formed on the peripheral surface of the support shaft 9, when the hub 11 
is telescoped over the shaft. The vanes 12 in the illustrated embodiment 
are formed each in the shape of a shallow arc so that when any external 
force is exerted upon the leading ends of the vanes, the vanes will bend 
resiliently by virtue of the arcs. Further, the free or leading ends of 
the vanes are formed in straight edges running parallel to the axial 
direction of the bearing, and preferably include a radiused bead extending 
transversely of each vane, with the edges collectively falling on the 
curved surface of an imaginary cylinder of predetermined diameter. 
The rotary member 6 has the shape of a cup and is provided on the closed 
end surface thereof with an integral gear 15. This rotary member has a 
depth large enough to encase wholly the resisting member 5. It has an 
inside diameter slightly smaller than the diameter of the imaginery circle 
containing all the leading ends of the vanes 12 of the resisting member 5, 
so that when the resisting member is encased within the rotary member, the 
leading ends of the vanes 12 are forced to slide intimately on the inner 
wall surface of the rotary member. The rotary cup-shaped member 6 is 
provided circumferentially on the peripheral surface thereof with an 
annular rib or check portion 16. It is also provided at the center of the 
aforementioned closed end surface with a perforation 17 extending through 
the core of the gear toothed wheel 15. 
These component parts of the damper means, namely, the fitting member 4, 
the resisting member 5, and the rotary member 6 are separately formed of a 
thermoplastic synthetic resin. When they are put together in the following 
sequence, they complete the damper means. The first step to the assemblage 
is to insert the bearing 11 of the resisting member 5 around the support 
shaft 9 of the fitting member 4 and fit the ridges 14 into the grooves 13 
formed in the inner wall surface of the bearing so as to have the 
resisting member 5 nonrotatably fixed on the fitting member 4. Then, the 
rotary member 6 is set around the resisting member in such a manner as to 
enclose the resisting member wholly. Consequently, the vanes 12 of the 
resisting member are caused to slide on the inner wall surface of the 
rotary member and, at the same time, the leading end of the support shaft 
9 protruding from the bearing 11 of the resisting member 5 is received 
into the perforation 17. Further, the rotary member is pressed toward the 
fitting member side until the engaging claws 10 raised from the peripheral 
portion of the circular base plate 7 snap into engagement with the annular 
check portion 16 and the interior of the open end of the cup-shaped rotary 
member 6 rests on the bearing surface 7a, as seen in FIG. 3, to thereby 
support the rotary member at two axially spaced bearing points and to form 
a union between the rotary member and the fitting member. Thus, the damper 
means is assembled. Alternatively, the assemblage of the damper means may 
be effected by first inserting the resisting member 5 within the rotary 
member 6, then passing the support shaft 9 of the fitting member through 
the bearing 11 of the resisting member thereby causing the resisting 
member to be borne on the fitting member and, at the same time, allowing 
the engaging claws 10 of the fitting member to snap into fast engagement 
with the annular check portion 16. The procedure of the assemblage has no 
effect whatever on the actual performance of the damper means. 
The damper means of the present invention which has been assembled as 
described above is mounted on the cassette tape recorder by fastening the 
fitting pieces 8 of the fitting member with screws 18 to the opening of 
the cassette housing 1 and bringing the arcuate toothed piece 19 hanging 
from the door 2 into mesh with the toothed wheel 15 provided on the rotary 
member 6 as illustrated in FIG. 1. In this arrangement, the rotary member 
6 is rotated by the toothed piece 19 which is moved when the door is 
opened and closed. 
Since the leading radiused beaded ends of the vanes 12 of the fixed 
resisting member encased within the rotary member 6 resiliently slide on 
the inner wall surface of the cup-shaped barrel of the rotary member 6, 
the rotary member 6 is subject to the friction resistance. Thus, the 
rotation of the rotary member is retarded by this frictional resistance 
and, consequently, the door is prevented from being abruptly opened or 
closed. 
Where the door provided for the cassette housing is energized by a spring 
so as to be automatically opened on being released from a lock device, the 
damper means of the present invention permits effective abatement of the 
sharp leap of the door from the lock. The damper means similarly functions 
when the door is closed. Thus, the impacts produced on the tape and the 
tape recorder by the opening and closing motions of the door can be 
notably abated. 
The damper means of this invention is composed of a small number of 
component parts as described above. Moreover, these component parts have 
simple shapes enough to permit easy fabrication. They are so constructed 
that they can be readily assembled by being merely set into each other. 
Thus, the damper means can be manufactured very easily and can be provided 
at a low price.