Miscellaneous hardware (e.g. – bushing – carpet fastener – caster – Casters – Antifrictionally swivelled
Reexamination Certificate
2001-06-27
2003-03-11
Will, Thomas B. (Department: 3671)
Miscellaneous hardware (e.g., bushing, carpet fastener, caster,
Casters
Antifrictionally swivelled
C016S026000, C016S037000, C016S03500D, C016S03500D
Reexamination Certificate
active
06530119
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is related to an improved caster structure having better connection strength for more stably support an appliance, whereby the appliance can be more freely moved and rotated.
FIG. 6
shows a conventional caster having a seat body
81
mounted under the bottom of an appliance. The seat body
81
has a fixing hole
811
for a fixing section
821
of a thread rod
82
to pass therethrough and be riveted and fixed. An upper bearing cover
83
, a caster seat
84
and a lower bearing cover
85
are fitted on the bottom end of the thread rod
82
. Multiple beads
86
are disposed between the upper bearing cover
83
, caster seat
84
and lower bearing cover
85
to form a thrust bearing. A nut
87
is screwed on the rear end of the thread rod
82
to fix the same. A wheel
841
is rotatably connected with the caster seat
84
.
Referring to
FIG. 7
, when moving the appliance, the total weight of the appliance is loaded onto the caster
841
. Accordingly, the thread rod
82
, caster seat
84
and the upper and lower bearing covers
83
,
85
all suffer considerably great stress in different directions. After a period of use, the thread rod
82
is simply riveted with the seat body
81
and is not restricted from rotation. Therefore, when suffering the force, the fixing section
821
of the thread rod
82
will rotate and swing within the fixing hole
811
of the seat body
81
to enlarge the fixing hole
811
. Also, the rivet section of the fixing section
821
will be worn out and deformed. As a result, the thread rod
82
will swing to affect the stability of the appliance and the caster no more simply suffers axial force from the appliance. Accordingly, the caster seat
84
will be seriously tilted and when pushing the appliance, a corner of the appliance may suddenly lose the support to lead to unbalance of the appliance. Under such circumstance, the appliance may fall down and cause danger. Furthermore, moving the appliance, the upper bearing cover
83
will suffer force in different directions to gradually enlarge the hole
831
in which the thread rod
82
is fitted. Also, the upper bearing cover
83
will bend, deform and loosen. Accordingly, the gap between the circumference
832
of the upper bearing cover
83
and the caster seat
84
will be enlarged and the bead
86
may drop out and lose the effect of the thrust bearing. As a result, it will be hard to rotate and change the direction of the caster seat
84
.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide an improved caster structure in which the seat body is formed with a differential fixing hole and the top of the linking member is formed with a fixing section. The shape of the cross-section of the fixing section is an internal tangential circle of the differential fixing hole. When the fixing section is passed through the fixing hole and compressed and fixedly riveted, the fixing section will form a differential section complementary to the fixing hole. Accordingly, the linking member is firmly connected with the seat body without rotation. Therefore, the linking member and the seat body are prevented from being worn out and deformed and the problem caused by tilting of the linking member can be avoided and the appliance can be stably moved.
It is a further object of the present invention to provide the above caster structure in which the upper bearing cover is integrally formed with the linking member so that the upper bearing cover is not subject to wearing and deformation. The bearing section of the caster seat is formed with an annular rib corresponding to the outer circumference of the upper bearing cover for stopping the beads from dropping out. Therefore, the thrust bearing effect can be kept and the caster seat can be freely moved to change the direction of the wheel.
The present invention can be best understood through the following description and accompanying drawings wherein:
REFERENCES:
patent: 1203879 (1916-11-01), Janzen
patent: 1233093 (1917-07-01), Malloy
patent: 1344864 (1920-06-01), Chesnutt
patent: 1576923 (1926-03-01), Malloy
patent: 1868552 (1932-07-01), Walter
patent: 2990191 (1961-06-01), Black
patent: 3127633 (1964-04-01), Schutz, Jr.
patent: 4219903 (1980-09-01), Black
patent: 4707880 (1987-11-01), Doyle et al.
patent: 4777697 (1988-10-01), Berndt
patent: 4835815 (1989-06-01), Mellwig et al.
patent: 5199131 (1993-04-01), Harris
patent: 3246355 (1984-06-01), None
patent: 3229938 (1985-03-01), None
patent: 4221541 (1993-01-01), None
patent: 55-140602 (1980-04-01), None
patent: 3-200401 (1991-02-01), None
Beach Thomas A.
Will Thomas B.
LandOfFree
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