GB2070742A - Securing device for external aircraft load - Google Patents

Abstract

A device for use in securing external loads to aircraft is arranged to apply a force to the load to prevent vibration by means of a plunger 6 which is moved by coacting dovetailed angled surfaces between wedges 1 and 3. The first wedge 1 is driven in a housing 10 by a sleeve 2 which engages a threaded rod 5, and is mounted on the sleeve by a spring (7) which moves it in the force applying direction. <IMAGE>

Description

SPECIFICATION Device for use in the securing of an external load to an aircraft This invention relates to a device for use in the securing of an external load to an aircraft which loads are held by claw action with pressure being exerted on the load by means of a plunger, displacement of angularly engaging surfaces of a wedge system serving to move the plunger.

In German Specification 28 04 856 a clawaction securing device is disclosed in which pivoted arms fitted with buffers are forced against the suspended external load to secure same against vibration. The pivot arms are moved by a wedge system and effect movement of a piston which has a wedge surface which acts on a ram positioned horizontally.

The ram is moved outwards to a greater or lesser degree according to the position of the piston. The ram contacts a lug on the pivot arms so these can be pivoted.

The arrangement is relatively complex and the device requires additional measures to prevent the securing system from working loose as a result of vibration occurring during flight.

This invention seeks to provide a device for the purpose previously referred to which will not loosen due to vibration occurring in flight and which has fewer moving parts than known devices.

According to this invention there is provided a device for use in securing an external load to an aircraft and for applying force to an external load through a plunger, the device comprising a first spring loaded wedge which is movable through an adjustable sleeve, the first wedge coacting with a second wedge which has an integral plunger part and interconnected therewith by a dovetail block and groove slide and coacting surfaces of the wedges being angled with respect to the sleeve.

This combination of features provides a simple device which cannot fail to operate as required. The invention makes it possible to apply relatively high securing forces involving only short paths of movement. The system reliably copes with the three-dimensional accelerations and vibrations occuring in flight, as the wedge surfaces in contact ensure optimum self-locking action.

An embodiment according to the invention is described in conjunction with the accompanying drawings, wherein: Figure 1 shows a longitudinal section through a device in accordance with the invention, and Figure 2 shows a cross-section through the device.

Referring to the drawings a first wedge part 1 is supported by a sleeve 2 in a housing 1 0.

The sleeve 2 engages a threaded shaft 5 which is supported at one end in the housing 10 with the other end being positioned in the sleeve 2 which is supported by the housing.

The first wedge 1 has a bore 11 which receives the sleeve 2, the shaft 5 and a spring 7.

The first wedge 1 is connected by a dovetail guide block and groove 4 to a second wedge 3 which extends perpendicularly thereto. The second wedge 3 is integral with a plunger 6 which is forced against the external load (not shown). The contacting wedge surfaces of each of the wedges 1, 3 and the dovetail guide 4 are inclined.

Fig. 1 shows the position of the two wedges before a load is secured. To effect the securing operation the sleeve 2 is rotated so that the first wedge 1 moves to the right (as viewed in the drawing) and the spring 7 is compressed. As a result of the displacement of the first wedge 1 the second wedge 3 moves downwards along with the plunger 6.

The spring 7 prevents the wedges from loosening and being released in the event of lack of symmetry, as the first wedge 1 always tends to be moved to the right. Owing to the inclination of the wedge surfaces in relation to the movement of the wedges a self-locking action is obtained for all positions which cannot be overcome by forces produced by the external load but which can only be released by operating the sleeve 2. The sleeve 2 can be rotated either by hand or by means of a motor drive

CLAIMS 1. A device for use in securing an external load to an aircraft and for applying force to an external load through a plunger, the device comprising a first spring loaded wedge which is movable through an adjustable sleeve, the first wedge coacting with a second wedge which has an integral plunger part and interconnected therewith by a dovetail block and groove slide the coacting surfaces of the wedges being angled with respect to the sleeve.

2. A device for use in securing external loads to an aircraft substantially as herein described with reference to and as shown in the accompanying drawings.

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

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Device for use in the securing of an external load to an aircraft This invention relates to a device for use in the securing of an external load to an aircraft which loads are held by claw action with pressure being exerted on the load by means of a plunger, displacement of angularly engaging surfaces of a wedge system serving to move the plunger. In German Specification 28 04 856 a clawaction securing device is disclosed in which pivoted arms fitted with buffers are forced against the suspended external load to secure same against vibration. The pivot arms are moved by a wedge system and effect movement of a piston which has a wedge surface which acts on a ram positioned horizontally. The ram is moved outwards to a greater or lesser degree according to the position of the piston. The ram contacts a lug on the pivot arms so these can be pivoted. The arrangement is relatively complex and the device requires additional measures to prevent the securing system from working loose as a result of vibration occurring during flight. This invention seeks to provide a device for the purpose previously referred to which will not loosen due to vibration occurring in flight and which has fewer moving parts than known devices. According to this invention there is provided a device for use in securing an external load to an aircraft and for applying force to an external load through a plunger, the device comprising a first spring loaded wedge which is movable through an adjustable sleeve, the first wedge coacting with a second wedge which has an integral plunger part and interconnected therewith by a dovetail block and groove slide and coacting surfaces of the wedges being angled with respect to the sleeve. This combination of features provides a simple device which cannot fail to operate as required. The invention makes it possible to apply relatively high securing forces involving only short paths of movement. The system reliably copes with the three-dimensional accelerations and vibrations occuring in flight, as the wedge surfaces in contact ensure optimum self-locking action. An embodiment according to the invention is described in conjunction with the accompanying drawings, wherein: Figure 1 shows a longitudinal section through a device in accordance with the invention, and Figure 2 shows a cross-section through the device. Referring to the drawings a first wedge part 1 is supported by a sleeve 2 in a housing 1 0. The sleeve 2 engages a threaded shaft 5 which is supported at one end in the housing 10 with the other end being positioned in the sleeve 2 which is supported by the housing. The first wedge 1 has a bore 11 which receives the sleeve 2, the shaft 5 and a spring 7. The first wedge 1 is connected by a dovetail guide block and groove 4 to a second wedge 3 which extends perpendicularly thereto. The second wedge 3 is integral with a plunger 6 which is forced against the external load (not shown). The contacting wedge surfaces of each of the wedges 1, 3 and the dovetail guide 4 are inclined. Fig. 1 shows the position of the two wedges before a load is secured. To effect the securing operation the sleeve 2 is rotated so that the first wedge 1 moves to the right (as viewed in the drawing) and the spring 7 is compressed. As a result of the displacement of the first wedge 1 the second wedge 3 moves downwards along with the plunger 6. The spring 7 prevents the wedges from loosening and being released in the event of lack of symmetry, as the first wedge 1 always tends to be moved to the right. Owing to the inclination of the wedge surfaces in relation to the movement of the wedges a self-locking action is obtained for all positions which cannot be overcome by forces produced by the external load but which can only be released by operating the sleeve 2. The sleeve 2 can be rotated either by hand or by means of a motor drive CLAIMS

1. A device for use in securing an external load to an aircraft and for applying force to an external load through a plunger, the device comprising a first spring loaded wedge which is movable through an adjustable sleeve, the first wedge coacting with a second wedge which has an integral plunger part and interconnected therewith by a dovetail block and groove slide the coacting surfaces of the wedges being angled with respect to the sleeve.

2. A device for use in securing external loads to an aircraft substantially as herein described with reference to and as shown in the accompanying drawings.