GB2139282A

GB2139282A - Telescopic stays

Info

Publication number: GB2139282A
Application number: GB08406912A
Authority: GB
Inventors: Frederick Edwards
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-05-04
Filing date: 1984-03-16
Publication date: 1984-11-07
Also published as: GB2139282B; GB8406912D0

Abstract

A friction clamp for fitting to a telescopic stay comprises two superimposed injection moulded plates (10, 11) secured to one another by threaded bolts (12) with respective nuts (13). Central recessed portions (14, 15) of the two plates cooperate to form a longitudinally split cylindrical passage. The passage is sub-divided into a large diameter portion (14a, 15a) which clamps around the cylinder of the telescopic stay, and a small diameter portion (14b, 15b) which slidably receives the retractable piston of the stay. The piston is thereby subjected to a frictional retarding force which is adjusted by loosening or tightening the wing nuts 13. <IMAGE>

Description

SPECIFICATION Telescopic stays This invention relates to telescopic stays of the type having a retractable piston or ram extending from a cylinder filled with a damping fluid. The stay may be used, for example, to releasably hold open the lid of a car boot or the tail-gate of a hatch back.

A problem with this type of stay is that failure of the damping mechanism is expensive to repair and may also cause an injury if it occurs unexpectedly.

In accordance with the invention this problem is overcome by the attachment of a safety device to the stay, the device comprising means for applying a frictional retarding force to the piston or ram, and means for adjusting the applied retarding force to control the rate of retraction. In use, the applied retarding force may vary between zero and a maximum value, the maximum value being sufficient to prevent movement of the piston or ram.

The device preferably comprises a longitudinally split sleeve, and means for adjustably tightening the sleeve around the piston or ram. In a preferred embodiment of the invention the sleeve is enlarged at one end and further means are provided for clamping the enlarged end around the cylinder.

By way of example only, a safety device embodying the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a front perspective view of the device; Figure 2 is a rear perspective view of the device; and Figure 3 is a schematic view showing the device fitted to a telescopic stay.

Referring to these drawings, the device 20 essentially comprises a friction clamp which consists of two superimposed injection moulded plates 10, 11 secured to one another by four threaded bolts 1 2 with respective nuts 13, two of the nuts 1 3 being wing nuts.

Central recessed portions 14 and 1 5 of the two plates cooperate to form a longitudinally split cylindrical passage. Each central recess is sub-divided into a large diameter portion 14a, 1 spa and a small diameter portion 1 4b, 1 Sb to provide cylindrical passage which is enlarged at one end. The remaining portions of the plates 10, 11 flanking the central passage serve as flanges 18, 1 9 for receiving the bolts 12.

In use, the enlarged end of the passage formed by recessed portions 1 4a, 1 spa is tightly clamped around the cylinder 1 6 of the telescopic stay shown in Fig. 3, the stay having a retractable piston or ram 1 7 movable against a damping fluid in the cylinder 16.

The smaller diameter portion of the passage formed by recessed portions 1 4b, 1 sub then forms a longitudinally split sleeve which is clamped around the piston 1 7 to apply a frictional retarding force.

The wing nuts 1 3 on opposite sides of the split sleeve 1 4b, 1 sub are loosened or tightened to adjust this frictional retarding force on the piston. In this manner the user is provided with independent control over the retraction rate of the stay and is thereby safeguarded against possible failure of the damping mechanism.

In one alternative embodiment (not illustrated) the two bolts in one of the longitudinal flanges 1 8 or 1 9 are replaced by a single hinge extending the length of the flange.

The device is particularly suited as a vehicle accessory for fitting to a gas-filled stay which, in use, releasably holds open either the tailgate, bonnet or boot lid of a motor vehicle.

1. A telescopic stay of the type having a retractable piston extending from a cylinder containing a damping fluid, the stay further comprising means for applying a frictional retarding force to the piston, and means for adjusting the applied retarding force to control the rate at which the piston is retracted into the cylinder.

2. A stay according to Claim 1 in which the frictional force is applied by a longitudinally split sleeve slidably receiving the piston.

3. A stay according to Claim 2 in which the diameter of the sleeve is enlarged at one end and clamped around the cylinder.

4. A stay according to Claim 2 or Claim 3 in which the two halves of the sleeve are hinged to one another along one side of the sleeve.

5. A stay according to Claim 2 or Claim 3 in which the two halves of the sleeve have at least one pair of opposed flanges fastened to one another.

6. A stay according to Claim 5 in which the frictional retarding force is adjusted by adjusting the tightness of at least one of the fastenings between the flanges.

7. A device for fitting to a telescopic stay of the type having a retractable piston extending from a cylinder, the device comprising: means defining a cylindrical passage including a first section with a diameter adapted to receive the cylinder, and a second section with a smaller diameter adapted to slidably receive the piston, at least the second section being split longitudinally; means for clamping the second section around the piston; and means for adjusting the clamping force on the second section to control the frictional retarding force applied to the piston.

8. A telescopic stay substantially as herein described with reference to the accompanying drawings.

9. A device for clamping to a telescopic

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Telescopic stays This invention relates to telescopic stays of the type having a retractable piston or ram extending from a cylinder filled with a damping fluid. The stay may be used, for example, to releasably hold open the lid of a car boot or the tail-gate of a hatch back. A problem with this type of stay is that failure of the damping mechanism is expensive to repair and may also cause an injury if it occurs unexpectedly. In accordance with the invention this problem is overcome by the attachment of a safety device to the stay, the device comprising means for applying a frictional retarding force to the piston or ram, and means for adjusting the applied retarding force to control the rate of retraction. In use, the applied retarding force may vary between zero and a maximum value, the maximum value being sufficient to prevent movement of the piston or ram. The device preferably comprises a longitudinally split sleeve, and means for adjustably tightening the sleeve around the piston or ram. In a preferred embodiment of the invention the sleeve is enlarged at one end and further means are provided for clamping the enlarged end around the cylinder. By way of example only, a safety device embodying the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a front perspective view of the device; Figure 2 is a rear perspective view of the device; and Figure 3 is a schematic view showing the device fitted to a telescopic stay. Referring to these drawings, the device 20 essentially comprises a friction clamp which consists of two superimposed injection moulded plates 10, 11 secured to one another by four threaded bolts 1 2 with respective nuts 13, two of the nuts 1 3 being wing nuts. Central recessed portions 14 and 1 5 of the two plates cooperate to form a longitudinally split cylindrical passage. Each central recess is sub-divided into a large diameter portion 14a, 1 spa and a small diameter portion 1 4b, 1 Sb to provide cylindrical passage which is enlarged at one end. The remaining portions of the plates 10, 11 flanking the central passage serve as flanges 18, 1 9 for receiving the bolts 12. In use, the enlarged end of the passage formed by recessed portions 1 4a, 1 spa is tightly clamped around the cylinder 1 6 of the telescopic stay shown in Fig. 3, the stay having a retractable piston or ram 1 7 movable against a damping fluid in the cylinder 16. The smaller diameter portion of the passage formed by recessed portions 1 4b, 1 sub then forms a longitudinally split sleeve which is clamped around the piston 1 7 to apply a frictional retarding force. The wing nuts 1 3 on opposite sides of the split sleeve 1 4b, 1 sub are loosened or tightened to adjust this frictional retarding force on the piston. In this manner the user is provided with independent control over the retraction rate of the stay and is thereby safeguarded against possible failure of the damping mechanism. In one alternative embodiment (not illustrated) the two bolts in one of the longitudinal flanges 1 8 or 1 9 are replaced by a single hinge extending the length of the flange. The device is particularly suited as a vehicle accessory for fitting to a gas-filled stay which, in use, releasably holds open either the tailgate, bonnet or boot lid of a motor vehicle. CLAIMS

9. A device for clamping to a telescopic stay, the device being substantially as herein described with reference to Figs. 1 and 2 of the accompanying drawings.