U.S. patent application number 09/983149 was filed with the patent office on 2003-05-08 for rolled-up blind driving mechanism.
Invention is credited to Cheng, Keng Mu.
Application Number | 20030085003 09/983149 |
Document ID | / |
Family ID | 25529813 |
Filed Date | 2003-05-08 |
United States Patent
Application |
20030085003 |
Kind Code |
A1 |
Cheng, Keng Mu |
May 8, 2003 |
Rolled-up blind driving mechanism
Abstract
A rolled-up blind driving mechanism includes a chain of beads
adapted to rotate a chain wheel assembly to further drive a
torsional spring on a spring holder to rotate an axle sleeve in
rolling up/letting off the blind, the torsional spring having two
end tips, a curved connecting arm, and two coils connected between
the connecting arm and the end tips of the rolled-up blind, the
connecting arm and the end tips being disposed at two sides of an
inside protruding portion of the axle sleeve for enabling the axle
sleeve to be rotated to roll up/let off the blind of the rolled-up
blind when pulling the chain of beads to rotate the chain wheel
assembly clockwise/counter-clockwise on the spring holder.
Inventors: |
Cheng, Keng Mu; (Taipei,
TW) |
Correspondence
Address: |
Felix J. D'Ambrosio
JONES, TULLAR & COOPER, P.C.
P.O. Box 2266 Eads Station
Arlington
VA
22202
US
|
Family ID: |
25529813 |
Appl. No.: |
09/983149 |
Filed: |
October 23, 2001 |
Current U.S.
Class: |
160/321 |
Current CPC
Class: |
E06B 9/90 20130101; E06B
9/42 20130101; E06B 9/78 20130101 |
Class at
Publication: |
160/321 |
International
Class: |
A47G 005/02 |
Claims
What the invention claimed is:
1. A rolled-up blind driving mechanism comprising: a chain wheel
assembly, said chain wheel assembly comprising a chain wheel, a
center through hole extended through the center of said chain
wheel, a semispherical shell axially extended from one side of said
chain wheel around the center through hole of said chain wheel,
said semispherical shell having a first side edge and a second side
edge; a chain of beads hung on said chain wheel of said chain wheel
assembly for pulling by hand to rotate said chain wheel assembly; a
wheel cap, said wheel cap comprising a cap ring adapted to receive
the semispherical shell of said chain wheel assembly, and a
smoothly arched cap flange perpendicularly backwardly extended from
the periphery of said cap ring and adapted to hold said chain of
beads in engagement with said chain wheel of said chain wheel
assembly; an axle sleeve, said axle sleeve comprising a sleeve hole
axially extended through front and rear ends thereof and adapted to
receive the semispherical shell of said chain wheel assembly, a
retaining groove axially extended in the periphery thereof for
engagement with the positioning rid of the blind roller of the
rolled-up blind in which the rolled-up blind driving mechanism is
installed, and an inside protruding portion protruded from an
inside wall thereof, said inside protruding portion having a first
sidewall and a second sidewall; a spring holder, said spring holder
comprising an end cap engaged with one side of said chain wheel of
said chain wheel assembly, and a shaft axially extended from the
center of one side of said end cap and inserted into the center
through hole of said chain wheel assembly; a torsional spring
mounted on the shaft of said spring holder; and fastener means,
which secures said spring holder to said axle sleeve; characterized
in that said torsional spring comprises a curved connecting arm
inserted into the space inside said axle sleeve between the second
side edge of said semispherical shell of said chain wheel assembly
and the second sidewall of said inside protruding portion of said
axle sleeve, two coils mounted on the shaft of said spring holder
inside said axle sleeve, said coils each having an inner end
respectively connected to two distal ends of said curved connecting
arm and an outer end, and two end tips respectively connected to
the outer end of each of said coils and inserted into the space
inside said axle sleeve between the first side edge of said
semispherical shell of said chain wheel assembly and the first
sidewall of said inside protruding portion of said axle sleeve.
2. The rolled-up blind driving mechanism as claimed in claim 1
wherein said torsional spring is made of a spring wire by
winding.
3. The rolled-up blind driving mechanism as claimed in claim 1
wherein said spring holder comprises a pinhole of non-circular
cross section axially extended through said end cap and said shaft;
said fastener means is a split pin inserted through said pinhole of
said spring holder to secure said spring holder to said axle
sleeve, said split pin comprising a conical first end disposed
outside said spring holder and said axle sleeve, a shoulder stopped
at one end of said axle sleeve, a second end of non-circular cross
section fitted into said pinhole of said spring holder, and a stop
rod extended from said second end for positioning in the bracket of
the rolled-up blind in which the rolled-up blind driving mechanism
is installed.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a rolled-up blind and, more
specifically, to a rolled-up blind driving mechanism, which can
easily be operated with less effort to roll up/let off the blind of
the rolled-up blind.
[0002] FIG. 1 shows a conventional rolled-up blind 9. This
structure of rolled-up blind 9 comprises a driving mechanism 90
adapted to roll up or let off the blind 97. The driving mechanism
90 comprises a chain wheel assembly 92, an axle sleeve 95 supported
on the chain wheel assembly 92 and coupled to the blind roller 96
of the rolled-up blind 9, a spring holder 93, a torsional spring 94
mounted on the spring holder 93, and a chain of beads 91 hung on
the chain wheel assembly 92 (see also FIG. 2).
[0003] When pulling the chain of beads 91 to rotate the chain wheel
assembly 92, the torsional spring 94 is forced to rotate the axle
sleeve 95 and the blind roller 96, causing the blind roller 96 to
roll up or let off the blind 97. When released the chain of beads
91, the mechanical friction between the torsional spring 94 and the
spring holder 93 stops the axle sleeve 95 from rotation. When
rotating the axle sleeve, the torque applied to the torsional
spring 94 must surpass the friction force between the torsional
spring 94 and the axle sleeve 95 so that the torsional spring 94
can be released from the spring holder 93 and rotated relative to
the spring holder 93.
[0004] However, because the torque can only be applied to one end
tip 98 and then to the coil 99 of the torsional spring 94, much
effort should be employed to the torsional spring 94 to release the
coil 99 from the spring holder 93 due to long arm of force
(torque=force.times.arm of force). It is known that reducing the
number of turns of the coil 99 of the torsional spring 93 shortens
the arm of force. However, a torsional spring having less number of
turns is not suitable for use in a bid scale rolled-up blind.
SUMMARY OF THE INVENTION
[0005] The present invention has been accomplished under the
circumstances in view.
[0006] It is the main object of the present invention to provide a
driving mechanism for a rolled-up blind, which provides sufficient
brake force to stop the blind roller from rotation and, can be
operated to rotate the blind roller with less effort.
[0007] According to the present invention, the rolled-up blind
driving mechanism comprises a chain of beads adapted to rotate a
chain wheel assembly to further drive a torsional spring on a
spring holder to rotate an axle sleeve in rolling up/letting off
the blind. The torsional spring has two end tips, a curved
connecting arm, and two coils connected between the connecting arm
and the end tips of the rolled-up blind. The connecting arm and the
end tips are disposed at two sides of an inside protruding portion
of the axle sleeve for enabling the axle sleeve to be rotated the
end tips/connecting arm of the torsional spring to roll up/let off
the blind of the rolled-up blind when pulling the chain of beads to
rotate the chain wheel assembly clockwise/counter-clockwise on the
spring holder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a sectional view showing a rolled-up blind driving
mechanism installed in a rolled-up blind according to the prior
art.
[0009] FIG. 2 is a sectional view taken along line A-A of FIG.
1.
[0010] FIG. 3 is an elevational view of a rolled-up blind driving
mechanism constructed according to the present invention.
[0011] FIG. 4 is an exploded view of the rolled-up blind driving
mechanism according to the present invention.
[0012] FIG. 5 is a longitudinal view in section of the rolled-up
blind driving mechanism according to the present invention.
[0013] FIG. 6 is a sectional view taken along line C-C of FIG.
5.
[0014] FIG. 7 is a sectional view showing the rolled-up blind
driving mechanism installed in a rolled-up blind according to the
present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Referring to FIGS. from 3 through 5, a rolled-up blind
driving mechanism 10 is shown comprised of a chain wheel assembly
1, a chain of beads 2, a wheel cap 3, an axle sleeve 4, a spring
holder 5, a torsional spring 6, and a split pin 7.
[0016] The chain wheel assembly 1 comprises a chain wheel 11 on
which the chain of beads 2 hung and pulled to rotate the chain
wheel assembly 1 clockwise/counter-clockwise, a center through hole
13 extended through the center of the chain wheel 11 and adapted to
receive the spring holder 5, a semispherical shell 12 axially
extended from one side of the chain wheel 11 around the center
through hole 13. The semispherical shell 12 has a first side edge
14 and a second side edge 15 adapted to drive the torsional spring
6 (this will be described further).
[0017] The wheel cap 3 comprises a cap ring 31 adapted to receive
the semispherical shell 12 of the chain wheel assembly 1, and a
smoothly arched cap flange 32 perpendicularly backwardly extended
from the periphery of the cap ring 31 and adapted to hold the chain
of beads 2 in engagement with the chain wheel 11 of the chain wheel
assembly 1.
[0018] The axle sleeve 4 comprises a sleeve hole 41 axially
extended through front and rear ends thereof, a retaining groove 42
axially extended in the periphery for engagement with the
positioning rid 82 of the blind roller 81 (see FIG. 7) for enabling
the blind roller 81 to be synchronously rotated with the axle
sleeve 4, and an inside protruding portion 43 protruded from the
inside wall thereof, The inside protruding portion 43 has a first
sidewall 44 and a second sidewall 45 (see FIG. 6). When the
semispherical shell 12 of the chain wheel assembly 1 inserted into
the sleeve hole 41 of the axle sleeve 4, the first side edge 14 of
the semispherical shell 12 faces the first sidewall 44 of the
inside protruding portion 43, and the second side wedge 15 of the
semispherical shell 12 faces the second sidewall 45 of the inside
protruding portion 43 (the effect of this arrangement will be
described further).
[0019] The spring holder 5 comprises an end cap 51, a shaft 52
axially extended from the center of one side of the end cap 51, and
a pinhole 53 axially extended through the end cap 51 and the shaft
52. The pinhole 53 has a substantially D-shaped cross section. The
shaft 52 is inserted into the center through hole 13 of the chain
wheel assembly 1, keeping the end cap 51 engaged with one side of
the chain wheel 11.
[0020] The torsional spring 6 is made of a resilient spring wire by
winding, comprising two end tips 63, a curved connecting arm 62,
and two coils 61 connected between the end tips 63 and two distal
ends of the curved connecting arm 62 and sleeved onto the shaft 52
of the spring holder 5 in an interference-fit manner The friction
force between the coils 61 and the shaft 52 prevents the blind from
being automatically let off. The free end of the curved connecting
arm 62 is inserted into the space between the second side edge 15
of the semispherical shell 12 of the chain wheel assembly 1 and the
second sidewall 45 of the inside protruding portion 43 of the axle
sleeve 4 (see FIG. 6). The end tips 63 of the torsional spring 6
are inserted into the space between the first side edge 14 of the
semispherical shell 12 of the chain wheel assembly 1 and the first
sidewall 44 of the inside protruding portion 43 of the axle sleeve
4 (see FIG. 6). When rotating the chain wheel assembly 1, the
torsional spring 6 is driven to rotate the axle sleeve 4.
[0021] The split pin 7 comprises a first end 71 and a second end
72. The first end 71 is shaped like a truncated cone. The greatest
diameter of the first end 71 is greater than the diameter of the
body of the split pin 7, so that a shoulder 73 is defined between
the first end 71 and the body of the split pin 7. A longitudinal
split 74 extends axially through the first end 71. The second end
72 has a D-shaped cross section fitted into the pinhole 53 of the
spring holder 5. A stop rod 75 is extended from the second end 72,
having a bottom notch 76. After insertion of the split pin 7
through the pinhole 53 of the spring holder 5 and the sleeve hole
41 of the axle sleeve 4, the shoulder 73 is stopped at the front
end of the axle sleeve 4, keeping the spring holder 5 secured to
the axle sleeve 4. Because the second end 72 has a D-shaped cross
section fitting the D-shaped cross section of the pinhole 53 of the
spring holder 5, the spring holder 5 is prohibited from rotary
motion relative to the split pin 7. When assembled, a gap 77 is
left between the end cap 51 of the spring holder 5 and the top rod
75 for the positioning of the bracket, referenced by 84 to stop the
split pin 7 from falling out of position (see FIG. 7). Further,
other fastener means, for example, screw means may be used instead
of the split pin 7 to secure the spring holder 5 to the axle sleeve
4.
[0022] Referring to FIGS. 6 and 7, when pulling the chain of beads
2 to rotate the chain wheel assembly 1 clockwise after installation
of the rolled-up blind driving mechanism in the rolled-up blind 8,
the second side edge 15 of the semispherical shell 12 of the chain
wheel assembly 1 is forced against the connecting arm 62 to release
(expand) the coils 61, thereby causing the torsional spring 6 to
rotate on the shaft 52 of the spring holder 5, and at this time the
end tips 63 of the torsional spring 6 are forced against the second
sidewall 45 of the inside protruding portion 43 of the axle sleeve
4, causing the axle sleeve 4 to rotate the blind roller 81 in
letting off the blind 83.
[0023] On the contrary, when pulling the chain of beads 2 to rotate
the chain wheel assembly 1 counter-clockwise, the first side edge
14 of the semispherical shell 12 of the chain wheel assembly 1 is
forced against the end tips 63 to release (expand) the coils 61,
thereby causing the torsional spring 6 to rotate on the shaft 52 of
the spring holder 5, and at this time the end tips 63 of the
torsional spring 6 are forced against the first sidewall 44 of the
inside protruding portion 43 of the axle sleeve 4, causing the axle
sleeve 4 to rotate the blind roller 81 in rolling up the blind
83.
[0024] When released the chain of beads 2, the coils 61 immediately
return to their former shape and are positively secured to the
periphery of the shaft 52 of the spring holder 5 due to the effect
of interference fit, keeping the blind 83 in position, and
therefore the blind 83 is prohibited from extending out.
[0025] A prototype of rolled-up blind driving mechanism has been
constructed with the features of FIGS. 3.about.7. The rolled-up
driving mechanism functions smoothly to provide all of the features
discussed earlier.
[0026] Although a particular embodiment of the invention has been
described in detail for purposes of illustration, various
modifications and enhancements may be made without departing from
the spirit and scope of the invention. Accordingly, the invention
is not to be limited except as by the appended claims.
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