<'
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`(19) Japan Patent Office (JP)
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`(II) Japanese Unexamined Patent
`Application Publication
`
`(t2)Japanese Unexamined Patent
`Application Publication (A)
`
`854-38648
`
`(51) Int. Cl.2
`
`E 06B
`
`9/322
`
`Identification
`codes
`
`(52) Japanese
`classification
`89(2) D 4ll
`
`(54) Venetian blinds roll-up device
`
`852-105456
`(21) Japanese patent application
`(22) Filed
`September 2, 1977
`T ACHIKA W A, Takeyoshi
`(72) Inventor
`c/o Tachikawa Blind Kogyo K.K., 30-7
`Yoyogi 4-chome, Shibuya-k:u, Tokyo-to
`
`JPO file numbers
`
`(43) Published: March 23, 1979
`
`7369-2E
`
`Number of inventions: l
`Request for examination: requested
`
`(Total of 4 pages)
`
`(71) Applicant
`
`Tachikawa Blind Kogyo K.K., 30-7
`Yoyogi 4-chome, Shibuya-ku, Tokyo-to
`
`(74) Agent
`
`Patent attorney TANROKU, Ryoji and I
`other
`
`SPECIFICATION
`
`1. TITLE OF THE INVENTION
`Venetian blinds roll-up device
`2. SCOPE OF PATENT CLAIMS
`A venetian blinds roll-up device characterized
`in that a constant force spring is mounted on a
`drive shaft or operating shaft for performing the
`rolling up of venetian blinds, and the radius of
`curvature of the constant force spring is changed
`in response to the change
`in
`the gradually
`increasing load as the blinds are rolled up, so as to
`constantly generate a spring torque corresponding
`to the load of the blinds.
`3. DETAILED DESCRIPTION OF THE INVENTION
`When venetians blinds are rolled up by
`turning the operating shaft of the blinds by means
`of a gear mechanism or the like, the load increases
`gradually
`as
`the
`roll-up progresses,
`and
`conversely when the blinds are rolled down, the
`load becomes smaller as the roll-down progresses.
`Therefore, the force necessary to manipulate the
`operating shaft of the blinds is not constant and
`changes ceaselessly.
`The present invention relates to a venetian
`blinds roll-up device characterized in
`that a
`constant force spring is mounted on the operating
`
`shaft of the venetian blinds, and the radius of
`curvature of the constant force spring is changed
`in response to the change in load as the blinds are
`rolled up, so as to constantly generate a spring
`torque in the opposite direction and identical to
`the torque due to the load of the blinds acting
`upon the operating shaft, which has the effect that
`the force for manipulating the operating shaft in
`order to perform roll-up and roll-down of the
`blinds can be a: small, constant force regardless of
`the position of the blinds, and that the blinds do
`not fall spontaneously due to the weight of the
`blinds if roll-up is stopped mid-way, but are rather
`stopped at that position by the spring torque.
`Regarding
`the
`illustrated
`embodiment
`example, an operating shaft 2
`is mounted
`horizontally on the upper case 1 of the venetian
`blinds, tapes 4, 4 are wound onto drums 3, 3
`attached to multiple locations on the operating
`shaft 2, and each tape 4 is passed through through(cid:173)
`holes in the slats 5, 5 of the blinds and is coupled
`to lower case 6. A bevel gear 7 is attached to one
`end of operating shaft 2, a chain pulley 10 is fixed
`to drive shaft 9 of bevel gear 8 which engages
`with bevel gear 7, and an endless chain II is hung
`on chain pulley I 0 and suspended downward.
`
`-209-
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`Norman Int. Exhibit 1002 Page 1
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`'·
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`Japanese Unexamined Patent Application Publication $54--38648 (2)
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`Conventional venetian blinds are configured
`as described above, whereby one side of chain 1I
`is pulled to tum the chain pulley 10, the operating
`shaft 2
`is
`turned
`through engagement and
`interlocking of the bevel gears 8 and 7, drums 3, 3
`tum in the same direction, the lower case 6 is
`pulled for example by the wrapping of tapes 4
`around the drums 3, and the slats 5, 5 are
`sequentially stacked on the lower case 6 and
`rolled up. Therefore, at the start of the roll-up,
`there is only the load of the lower case 6, . but as
`the roll-up progresses, the load of the slats 5 is
`applied, so the torque to be applied in order to
`tum the operating shaft 2 is not constant and
`changes ceaselessly.
`In the present invention, for the purpose of
`performing the turning of the operating shaft 2
`with a small constant force, as shown in FIG. I
`and FIG. 2, a constant force spring is mounted on
`the operating shaft 2, or as shown in FIG. 3 and
`FIG. 4, a constant force spring is mounted on
`drive shaft 9 which turns the operating shaft 2. In
`FIG. 2, support plate 12 is mounted inside the
`upper case 1, a shaft tube 13 which allows the
`operating shaft 2 to pass through and wedges it in
`place is secured to the support plate I2 (FIG. 6),
`I7
`is wound
`and a constant force spring
`diagonally between drum 14 fixed to shaft tube 13
`and drum I6 which is rotatably axially fitted onto
`center shaft 15 provided on support plate 12. Thus,
`in response to the torque of turning the operating
`shaft 2 based on the load P as the blinds are rolled
`up to the uppermost end, as shown in FIG. 9, the
`constant force spring 1 7 produces a torque T in
`the opposite direction and identical to the torque
`due to the load P based on reduction of the
`curvature radius R of the starting end wound onto
`drum 14, as shown in FIG. 8, and as the blinds are
`rolled down, the load P decreases gradually,
`changing gradually to load p when rolled down to
`the lowermost end, in response to which the
`curvature radius of the constant force spring 17 is
`gradually increased from the curvature radius R of
`the starting end to the curvature radius r of the
`terminal end shown in FIG. 7, so that a spring
`torque t in the opposite direction and identical to
`the torque on the operating shaft 2 due to load p is
`generated at the terminal end.
`When a constant force spring 17 ofthis sort is
`installed, it suffices to apply a small constant
`force in order to manipulate the endless chain 11
`via bevel gears 7, 8 in order to tum the operating
`
`shaft 2, and if the manipulation of the endless
`chain 11 is stopped mid-way during roll-up or
`roll-down of the blinds, the torque of the blinds
`descending under their own weight will be
`balanced out by an identical spring torque in the
`opposite direction due to the constant force spring,
`so the blinds will stop at the mid-way position.
`It will be noted that while it is ideal to change
`the radius of curvature of the constant force spring
`17 in response to change in load of the blinds such
`that its torque changes gradually from torque T to
`torque t, as shown in FIG. 9, there is no practical
`impediment to employing a constant force spring
`whereof the radius of curvature is machined to a
`fixed R so as to provide a spring torque P in a
`suitable range from the starting end, and whereof
`the radius of curvature is machined to a fixed r so
`as to provide a spring torque p at the terminal end,
`as shown by the dashed line in FIG. 9.
`The effect of the constant force spring 17 in
`FIG. 3 and FIG. 4, where it is mounted on drive
`shaft 9, is the same as above, and the constant
`force spring 17 can be suitably wound diagonally
`between drum 14 fixed to drive shaft 9 and drum
`16, which is rotatably axially fitted onto center
`shaft 15.
`4. BRIEF DESCRIPTION OF THE ORA WINGS
`FIG. I is a plan view of venetian blinds
`embodying the present invention; FIG. 2 is a
`vertical front cross-sectional view sectioned along
`line A-A ofFIG. I; FIG. 3 is a partial plan view of
`an embodiment example in which a constant force
`spring is mounted on the drive shaft of the
`venetian blinds; FIG. 4 is a partial front view
`vertically sectioned along line B-B of FIG. 3; FIG.
`5 is a diagonal view of a constant force spring;
`FIG. 6 is a vertical cross-sectional view along C-C
`of FIG. 5; FIG. 7 is a front view showing the state
`of the constant force spring at the position where
`the blinds have been fully lowered; FIG. 8 is a
`front view showing the state of the constant force
`spring at the position where the blinds have been
`fully raised and their load is greatest; FIG. 9 is a
`graph showing the change in load of the blinds
`and the change in spring torque of the constant
`force spring.
`1 ... upper case of blinds; 2 ··· operating shaft;
`3 ... drum; 4 ... tape; 5 ... slat; 6 ... lower case; 7,8
`··· bevel gear; 9 ··· drive shaft; 10 ··· chain pulley;
`11
`... endless chain; 12 ··· support plate; 13 ···
`shaft tube; 14 ·· · drum; I5 ··· center shaft; I6 · ··
`drum; 1 7 ... constant force spring.
`
`-210-
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`Norman Int. Exhibit 1002 Page 2
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`

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`Japanese Unexamined Patent Application Publication 854-38648 (3)
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`M
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`d -i:1.t
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`-211-
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`Norman Int. Exhibit 1002 Page 3
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`Japanese Unexamined Patent Application Publication 854-38648 (4)
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`FIG. 8
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`FIG. 7
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`FIG. 6
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`FIG. 5 -
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`13
`
`FIG. 9
`
`Load -Spring torque
`·---
`
`0
`
`Elongation (blinds roll-up position)
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`-212-
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`Norman Int. Exhibit 1002 Page 4
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`Norman Int. Exhibit 1002 Page 5
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`Norman Int. Exhibit 1002 Page 6
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`Norman Int. Exhibit 1002 Page 7
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`Norman Int. Exhibit 1002 Page 8