GB2136041A

GB2136041A - Loft ladders and safety catch therefor

Info

Publication number: GB2136041A
Application number: GB08305692A
Authority: GB
Inventors: Terence Arthur Lutterloch
Original assignee: STEPHENS and CARTER Ltd
Current assignee: STEPHENS and CARTER Ltd
Priority date: 1983-03-02
Filing date: 1983-03-02
Publication date: 1984-09-12
Also published as: GB8305692D0

Abstract

Ladder sections 13, 14 are slidably mounted upon each other. Uppermost section 14 is slidably mounted upon a carrier 15 connected by hinge 16 to a margin of a loft aperture. A safety catch 20 is provided upon uppermost section 14. Catch 20 has a sinuous channel 21 into which a stop 19, on carrier 15, can be engaged to support uppermost section 14 against downward movement. Stop 19 is disengaged by upward movement of uppermost section 14. <IMAGE>

Description

SPECIFICATION Loft ladders This invention relates to loft ladders intended to be mounted in a trap door aperture and consisting of two or more ladder sections slidably mounted upon each other, the upper end of the upper section being hinged to one margin of the aperture and the arrangement being such that the ladder can be stored away when not required for use by pushing the sections upwardly to overlie each other and then rotating them into the loft space.

It is an object of the present invention to provide an improved loft ladder which is simple in construction and operation and which is safe in use.

The present invention consists in a loft ladder which includes two or more ladder sections slidably mounted upon each other, the uppermost section being slidably mounted upon a carrier intended to be connected by means of a hinge to a margin of a loft aperture, wherein a safety catch is provided upon the uppermost section for cooperation with a fixed stop on the carrier, the catch having a sinuous channel into which the stop can be engaged to support the uppermost section against downward movement relative to the carrier and from which it can be disengaged by upward movement of the uppermost section relative to the channel.

In the accompanying drawings:- Figure 1 shows diagrammatically one form of loft ladder according to the present invention; Figure 2 is a general view of the safety catch on the ladder of figure 1; and Figures 3 to 9 show successive stages in the operation of the safety catch.

In carrying the invention into effect according to one convenient mode by way of example, figure 1 shows a loft ladder mounted in a trap door aperture 11 in a ceiling 12, the ladder being shown in its lowered or opened position.

The ladder includes a lower section 1 3 slidably mounted in an upper section 14 which in turn is slidably mounted in a carrier 1 5 connected to the floor above the ceiling 12 by a hinge 1 6 having a hinge pin 19. The lower end of the lower section 13 is supported on the floor 17 below the trap door aperture 11 and the carrier 1 5 is provided with three alternative positions for the hinge pin 19, so that the ladder can rest at an appropriate angle having regard to the height between the two floors.

The upper section 14 of the ladder is provided with a safety catch 20 pivotally mounted upon the section 14 by means of a bolt 18 and arranged to co-operate with the laterally projecting end of the hinge pin 19 which serves as a fixed stop. The catch 20 has a sinuous or S-shaped groove or channel 21 at one end and a counterweight 22 at the other.

The action of the safety catch 20 can best be explained by considering the sequence of raising the ladder to a locked position as shown in Figures 3 to 5, and then unlocking and lowering it again as shown in Figures 4 to 9.

To start closing the ladder the lower section 13 is first pushed upwardly to overlie the upper section 14 where it can be locked relative to the upper section 14 by means (not shown).

The two sections are then pushed upwardly in the carrier 15. As the safety catch 20 is moved towards the hinge pin 19, the catch 20 is maintained in a generally horizontal position (as shown in Figure 3) by its counterweight 22.

As a result of further upward movement, the end of the hinge pin 1 9 first enters the S-shaped channel 21 and thereafter rotates the catch in an anti-clockwise direction to the position shown in Figure 4.

If then the upper ladder section 14 is lowered slightly, the hinge pin 1 9 progresses further through the channel 21 to the position shown in figure 5. At this point the ladder section 14 is firmly locked against any further downward movement, the weight of the two sections being supported by the hinge pin 1 9 via the catch 20.

In this position the ladder may be fully closed by rotating the two sections into the loft about the pin 19.

The safety catch may be mounted upon the upper section by means of the bolt 18 at three different positions, the appropriate one being chosen to ensure that the lower ends of the sections 1 3 and 14 clear the edge of the trap door aperture opposite the hinge.

In order to prevent the catch 20 from spinning through 3600 whilst being moved to the position shown in figure 4, by example due to impact on a too abrupt upward movement of the sections, a safety step 23 is provided on the catch 20 for engagement with the underneath of section 14 to prevent anti-clockwise rotation of the catch 20 much beyond the position shown in figure 4.

To lower the ladder, the sections are first rotated in the opposite direction to return to the position shown in figure 5.

Thereafter, the upper section 14 is pushed upwardly until the hinge pin 1 9 passes out of the channel 21 as shown in figure 6. The safety catch 20 can then rotate in a clockwise direction under the effect of its counterweight 22 to the position shown in figure 7.

The ladder sections 13 and 14 can then be lowered for use as shown in figures 8 and 9, the catch 20 passing the pin 19 on the way down by rotation of the catch as shown in figure 8.

1. A loft ladder which includes two or more ladder sections slidably mounted upon each other, the uppermost section being slidably mounted upon a carrier intended to be connected by means of a hinge to a margin of a loft aperture, wherein a safety catch is provided upon the uppermost section for co-operation with a fixed stop on the carrier, the catch having a sinuous channel into which the stop can be engaged to support the uppermost section against downward movement

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Loft ladders This invention relates to loft ladders intended to be mounted in a trap door aperture and consisting of two or more ladder sections slidably mounted upon each other, the upper end of the upper section being hinged to one margin of the aperture and the arrangement being such that the ladder can be stored away when not required for use by pushing the sections upwardly to overlie each other and then rotating them into the loft space. It is an object of the present invention to provide an improved loft ladder which is simple in construction and operation and which is safe in use. The present invention consists in a loft ladder which includes two or more ladder sections slidably mounted upon each other, the uppermost section being slidably mounted upon a carrier intended to be connected by means of a hinge to a margin of a loft aperture, wherein a safety catch is provided upon the uppermost section for cooperation with a fixed stop on the carrier, the catch having a sinuous channel into which the stop can be engaged to support the uppermost section against downward movement relative to the carrier and from which it can be disengaged by upward movement of the uppermost section relative to the channel. In the accompanying drawings:- Figure 1 shows diagrammatically one form of loft ladder according to the present invention; Figure 2 is a general view of the safety catch on the ladder of figure 1; and Figures 3 to 9 show successive stages in the operation of the safety catch. In carrying the invention into effect according to one convenient mode by way of example, figure 1 shows a loft ladder mounted in a trap door aperture 11 in a ceiling 12, the ladder being shown in its lowered or opened position. The ladder includes a lower section 1 3 slidably mounted in an upper section 14 which in turn is slidably mounted in a carrier 1 5 connected to the floor above the ceiling 12 by a hinge 1 6 having a hinge pin 19. The lower end of the lower section 13 is supported on the floor 17 below the trap door aperture 11 and the carrier 1 5 is provided with three alternative positions for the hinge pin 19, so that the ladder can rest at an appropriate angle having regard to the height between the two floors. The upper section 14 of the ladder is provided with a safety catch 20 pivotally mounted upon the section 14 by means of a bolt 18 and arranged to co-operate with the laterally projecting end of the hinge pin 19 which serves as a fixed stop. The catch 20 has a sinuous or S-shaped groove or channel 21 at one end and a counterweight 22 at the other. The action of the safety catch 20 can best be explained by considering the sequence of raising the ladder to a locked position as shown in Figures 3 to 5, and then unlocking and lowering it again as shown in Figures 4 to 9. To start closing the ladder the lower section 13 is first pushed upwardly to overlie the upper section 14 where it can be locked relative to the upper section 14 by means (not shown). The two sections are then pushed upwardly in the carrier 15. As the safety catch 20 is moved towards the hinge pin 19, the catch 20 is maintained in a generally horizontal position (as shown in Figure 3) by its counterweight 22. As a result of further upward movement, the end of the hinge pin 1 9 first enters the S-shaped channel 21 and thereafter rotates the catch in an anti-clockwise direction to the position shown in Figure 4. If then the upper ladder section 14 is lowered slightly, the hinge pin 1 9 progresses further through the channel 21 to the position shown in figure 5. At this point the ladder section 14 is firmly locked against any further downward movement, the weight of the two sections being supported by the hinge pin 1 9 via the catch 20. In this position the ladder may be fully closed by rotating the two sections into the loft about the pin 19. The safety catch may be mounted upon the upper section by means of the bolt 18 at three different positions, the appropriate one being chosen to ensure that the lower ends of the sections 1 3 and 14 clear the edge of the trap door aperture opposite the hinge. In order to prevent the catch 20 from spinning through 3600 whilst being moved to the position shown in figure 4, by example due to impact on a too abrupt upward movement of the sections, a safety step 23 is provided on the catch 20 for engagement with the underneath of section 14 to prevent anti-clockwise rotation of the catch 20 much beyond the position shown in figure 4. To lower the ladder, the sections are first rotated in the opposite direction to return to the position shown in figure 5. Thereafter, the upper section 14 is pushed upwardly until the hinge pin 1 9 passes out of the channel 21 as shown in figure 6. The safety catch 20 can then rotate in a clockwise direction under the effect of its counterweight 22 to the position shown in figure 7. The ladder sections 13 and 14 can then be lowered for use as shown in figures 8 and 9, the catch 20 passing the pin 19 on the way down by rotation of the catch as shown in figure 8. CLAIMS

1. A loft ladder which includes two or more ladder sections slidably mounted upon each other, the uppermost section being slidably mounted upon a carrier intended to be connected by means of a hinge to a margin of a loft aperture, wherein a safety catch is provided upon the uppermost section for co-operation with a fixed stop on the carrier, the catch having a sinuous channel into which the stop can be engaged to support the uppermost section against downward movement relative to the carrier and from which it can be disengaged by upward movement of the uppermost section relative to the carrier.

2. A loft ladder as claimed in claim 1, wherein the safety catch is pivotally mounted upon the uppermost section and has means for biassing it into a position in which the entrance to the sinuous channel is presented to the fixed stop as the uppermost section is pushed upwardly towards the stop.

3. A loft ladder as claimed in claim 2, wherein the means for biassing consists of a counterweight.

4. A loft ladder as claimed in claim 1, 2 or 3, wherein the stop is arranged to be disengaged from the channel by upward movement of the uppermost section relative to the carrier to cause the stop to pass through the exit of the sinuous channel.

5. A loft ladder as claimed in any one of claims 1 to 4, wherein the hinge has a hinge pin, one laterally projecting end of which serves as the fixed stop.

6. A loft ladder as claimed in claim 5, wherein the hinge pin may be fitted at a number of different positions on the carrier.

7. A loft ladder as claimed in any one of claims 1 to 6, wherein the catch may be mounted upon the uppermost section at one of a number of different positions to suit the dimensions of the loft aperture.

8. A loft ladder substantially as described with reference to the accompanying drawings.