GB576202A - Improvements in and relating to safety shutters for windows and other apertures - Google Patents
Improvements in and relating to safety shutters for windows and other aperturesInfo
- Publication number
- GB576202A GB576202A GB778944A GB778944A GB576202A GB 576202 A GB576202 A GB 576202A GB 778944 A GB778944 A GB 778944A GB 778944 A GB778944 A GB 778944A GB 576202 A GB576202 A GB 576202A
- Authority
- GB
- United Kingdom
- Prior art keywords
- magnet
- switch
- shutter
- shutters
- safety
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B21/00—Projectors or projection-type viewers; Accessories therefor
- G03B21/14—Details
- G03B21/18—Fire preventing or extinguishing
Abstract
576,202. Safety shutters. DONALDSON, F. G. April 26, 1944, No. 7789. [Class 20 (iii)] [Also in Group XXI] A safety shutter for a projection room or other aperture is held by the direct action of an electro-magnet in the open position and allowed to fall under its own weight when the magnet is de-magnetised. In the arrangement shown in fig. 1, in which two shutters are connected by a pivoted lever 6, the heavier shutter 1 is held open by an armature 4 secured to it and bridging the poles of an electro-magnet 8 secured above the shutter frame. The current through the magnet is controlled by push button 13 or automatically by a tilting mercury switch 14, Fig. 4. mounted above the projector gate. A piece of film or other inflammable material attached to the sliding member 16 holds the spring 17 compressed and the switch in the closed circuit position. In a modification the switch, which is preferably situated near the film gate, is of ordinary type and thermally operated. In a further modification the switch is remote from the fusible material and controlled by Bowden wire mechanism or the like.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB778944A GB576202A (en) | 1944-04-26 | 1944-04-26 | Improvements in and relating to safety shutters for windows and other apertures |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB778944A GB576202A (en) | 1944-04-26 | 1944-04-26 | Improvements in and relating to safety shutters for windows and other apertures |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB576202A true GB576202A (en) | 1946-03-22 |
Family
ID=9839761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB778944A Expired GB576202A (en) | 1944-04-26 | 1944-04-26 | Improvements in and relating to safety shutters for windows and other apertures |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB576202A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5245879A (en) * | 1992-05-07 | 1993-09-21 | Mckeon Rolling Steel Door Co., Inc. | Fail-safe fire door release mechanism having automatic reset |
| US5355927A (en) * | 1992-12-17 | 1994-10-18 | Mckeon Rolling Steel Door Company, Inc. | Self-closing fire door |
| US5386891A (en) * | 1992-03-30 | 1995-02-07 | Anchuan Corporation | Mechanism for controlling the raising and lowering of a door |
-
1944
- 1944-04-26 GB GB778944A patent/GB576202A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5386891A (en) * | 1992-03-30 | 1995-02-07 | Anchuan Corporation | Mechanism for controlling the raising and lowering of a door |
| US5245879A (en) * | 1992-05-07 | 1993-09-21 | Mckeon Rolling Steel Door Co., Inc. | Fail-safe fire door release mechanism having automatic reset |
| US5355927A (en) * | 1992-12-17 | 1994-10-18 | Mckeon Rolling Steel Door Company, Inc. | Self-closing fire door |
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