GB2031493A

GB2031493A - Slat blind

Info

Publication number: GB2031493A
Application number: GB7928114A
Authority: GB
Original assignee: Louver Lite Ltd
Current assignee: Louver Lite Ltd
Priority date: 1978-09-09
Filing date: 1979-08-13
Publication date: 1980-04-23
Also published as: GB2031493B

Abstract

In a collapsible vertical slat blind the slats are pivoted on trucks D slidable on a grooved spindle 3. The slats are turnable through 90 DEG by rotation of the spindle by a chain wheel being transmitted via worm gearing 2, 1 which includes a slip clutch with engaging surfaces 7', 5. A hook carrying the slat is integral with a flanged pin extending into a bore in worm wheel 1, a spring 6 surrounding the pin being compressed between a circlip 8 at the end of the pin and a flange on worm 1 to bias surfaces 7', 5 together. <IMAGE>

Description

SPECIFICATION Slat-blind clutch for individual trucks This invention relates to improvements in collapsible vertical slat blinds of the kind in which the vertical slats are pivoted on trucks mounted to slids of a grooved spindle in a housing extending across the top of a window frame, doorway or like opening, the housing being formed of channel section to accommodate the trucks each supporting a vertical slat on a hook with manual means for rotating the hooks to open or close the slats and the sides of the channel being grooved longitudinally on each side adjacent the upper edge to accommodate supporting brackets for the housing.

It has been found that when opening or closing the slats they may overlap incorrectly and the mechanism jams with consequent damage and the object of the invention is to provide means for preventing damage if a slat is prevented from rotating.

According to the invention in a blind of the kind referred to each truck has a slat suspended therefrom capable of rotation through 90 from an open to a closed position by rotation of the grooved spindle, the spindle being rotated by a chain wheel rotating each slat through a worm gear, characterised by a slipping clutch being provided in the worm gear to prevent rotation of the slat if an obstruction is engaged by the slat.

The invention will be described with reference the accompanying drawings.

Figure 1 is a perspective view of one end of the housing; Figure 2 is a section on line 2-2 Fig. 1 to a larger scale; Figure 3 is a vertical section of the suspension hook to a larger scale; Figure 4 is an exploded view of the hook assembly; Figure 5 is a detail section on line 5-5 Fig.

2; A vertical slat collapsible blind A is formed of slats B suspended on hooks C depending from trucks D rotated through a worm 1 and worm wheel 2 from a grooved spindle 3 to open and close the slats. The slats B may be moved from a stacked position at one end of the spindle across a window, doorway or like opening by a cord b affixed to the outermost truck D. Adjacent trucks are connected by strips 4 one end of each strip being affixed to the truck and the other end turned upwardly to engage a slot in an adjacent truck to bring the upturned end against the side of the slot whereupon the second truck is drawn along the spindle by the first truck and so on until all trucks are positioned across the width of the window, doorway or other aperture.

The rotation of the spindle 3 is controlled by a chain wheel (not shown) over which passes a chain movement of which rotates the spindle 3 to bring the slats B from a position lying parallel side by side through 90 with their surfaces in line to cover the window, doorway or other aperture the width of each slat corresponding substantially to the length of the strip 4.

The spindle 3 is mounted in an inverted channel a and supported by end caps one of which houses the chaim wheel by which the spindle is rotated.

The construction above described is well known and does not form part of the invention.

In carrying out the invention each worm wheel 2 is formed with a grooved bore to engage the spindle 3 and drives the worm 1 to rotate the slats B suspended from the worm on each truck. Each worm 1 is formed with a hollow bore extended by an integral cylindrical bearing surface 5 in the truck and houses a coiled spring 6 surrounding a pin 7 on the end of which the hook C for carrying a slat is formed.

The surface 5 forms one member of a slipping clutch engaging a surface 7' on a disc 72 mounted on the pin 7 on which the hook C is carried and forming the second member of the slipping clutch.

The pin 7 is formed to project from a flange on the inside of the bottom of the truck D.

The spring 6 engages the back of the surface 5 and a circlip 8 sprung into a circumferential groove in the pin and a disc 81 to form the one member of the clutch between the worm wheel 1 and the pin 7 carrying hook C for the slat B. The second member of the clutch being the surface 71.

In normal use a drive is provided between the worm 1 and the pin 7 but should the slat encounter an obstruction slipping will occur between the worm 1 and the pin 7 and the obstructed slat B will not continue to rotate until the obstruction has been removed or righted but other trucks on the spindle will continue to rotate until arrested by a stop 73.

When the obstruction is removed the slat may be realined by rotation of the spindle 3 until again arrested by the stop 73.

1. A blind of the kind referred to in which each truck has a slat suspended therefrom capable of rotation through 90 from an open to a closed position by rotation of the grooved spindle the spindle being rotated by a chain wheel rotating each slat through a worm gear, characterised by a slipping clutch being provided in the worm gear to prevent rotation of the slat if an obstruction is engaged by the slat.

2. A blind as in claim 1, in which the slipping clutch is formed between a bearing surface on the worm engaging a spring loaded pin carrying the hook and housed in a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Slat-blind clutch for individual trucks This invention relates to improvements in collapsible vertical slat blinds of the kind in which the vertical slats are pivoted on trucks mounted to slids of a grooved spindle in a housing extending across the top of a window frame, doorway or like opening, the housing being formed of channel section to accommodate the trucks each supporting a vertical slat on a hook with manual means for rotating the hooks to open or close the slats and the sides of the channel being grooved longitudinally on each side adjacent the upper edge to accommodate supporting brackets for the housing. It has been found that when opening or closing the slats they may overlap incorrectly and the mechanism jams with consequent damage and the object of the invention is to provide means for preventing damage if a slat is prevented from rotating. According to the invention in a blind of the kind referred to each truck has a slat suspended therefrom capable of rotation through 90 from an open to a closed position by rotation of the grooved spindle, the spindle being rotated by a chain wheel rotating each slat through a worm gear, characterised by a slipping clutch being provided in the worm gear to prevent rotation of the slat if an obstruction is engaged by the slat. The invention will be described with reference the accompanying drawings. Figure 1 is a perspective view of one end of the housing; Figure 2 is a section on line 2-2 Fig. 1 to a larger scale; Figure 3 is a vertical section of the suspension hook to a larger scale; Figure 4 is an exploded view of the hook assembly; Figure 5 is a detail section on line 5-5 Fig. 2; A vertical slat collapsible blind A is formed of slats B suspended on hooks C depending from trucks D rotated through a worm 1 and worm wheel 2 from a grooved spindle 3 to open and close the slats. The slats B may be moved from a stacked position at one end of the spindle across a window, doorway or like opening by a cord b affixed to the outermost truck D. Adjacent trucks are connected by strips 4 one end of each strip being affixed to the truck and the other end turned upwardly to engage a slot in an adjacent truck to bring the upturned end against the side of the slot whereupon the second truck is drawn along the spindle by the first truck and so on until all trucks are positioned across the width of the window, doorway or other aperture. The rotation of the spindle 3 is controlled by a chain wheel (not shown) over which passes a chain movement of which rotates the spindle 3 to bring the slats B from a position lying parallel side by side through 90 with their surfaces in line to cover the window, doorway or other aperture the width of each slat corresponding substantially to the length of the strip 4. The spindle 3 is mounted in an inverted channel a and supported by end caps one of which houses the chaim wheel by which the spindle is rotated. The construction above described is well known and does not form part of the invention. In carrying out the invention each worm wheel 2 is formed with a grooved bore to engage the spindle 3 and drives the worm 1 to rotate the slats B suspended from the worm on each truck. Each worm 1 is formed with a hollow bore extended by an integral cylindrical bearing surface 5 in the truck and houses a coiled spring 6 surrounding a pin 7 on the end of which the hook C for carrying a slat is formed. The surface 5 forms one member of a slipping clutch engaging a surface 7' on a disc 72 mounted on the pin 7 on which the hook C is carried and forming the second member of the slipping clutch. The pin 7 is formed to project from a flange on the inside of the bottom of the truck D. The spring 6 engages the back of the surface 5 and a circlip 8 sprung into a circumferential groove in the pin and a disc 81 to form the one member of the clutch between the worm wheel 1 and the pin 7 carrying hook C for the slat B. The second member of the clutch being the surface 71. In normal use a drive is provided between the worm 1 and the pin 7 but should the slat encounter an obstruction slipping will occur between the worm 1 and the pin 7 and the obstructed slat B will not continue to rotate until the obstruction has been removed or righted but other trucks on the spindle will continue to rotate until arrested by a stop 73. When the obstruction is removed the slat may be realined by rotation of the spindle 3 until again arrested by the stop 73. CLAIMS

2. A blind as in claim 1, in which the slipping clutch is formed between a bearing surface on the worm engaging a spring loaded pin carrying the hook and housed in a bore in the worm.

3. A blind as in claim 1, in which each worm is formed with a hollow bore extended by a cylindrical bearing integral with the worm in the bottom of the truck to house the coiled spring surrounding the pin extending into the bore the worm wheel transmitting a drive to the pin and the hook through the slipping clutch from which a slat is suspended.

4. A blind as in claim 2 in which the coiled spring is compressed between the end of the bore and circlip sprung into a circumferential groove in the pin.

5. A blind of the type referred substantially as described with reference to the accompa nying drawings.