FIELD OF INVENTION

This invention relates to aircraft uplock assemblies in general including an emergency release mechanism for such assemblies.

BACKGROUND TO THE INVENTION

Uplock assemblies are used on aircraft "utility door systems such as a landing gear bay, weapon bays, arresting gear systems or any other in-flight opening door systems. Uplock assemblies are designed to keep utility door systems securely in a predetermined 'locked' closed position when use of the utility doors is not needed. Certain aircraft, depending on their applications, are fitted with a plurality of uplock assemblies to open various doors to allow for ultimate operation or deployment of landing gear, weapons or other such aircraft functions.

For example, when an aircraft is landing, a door covering an undercarriage well is opened to permit the landing gear to be deployed. When the landing gear is deployed, the door is usually open and an uplock assembly is unlatched, although on some types of aircraft the undercarriage well doors are closed when the landing gear is deployed. When the aircraft is flying, the landing gear is typically retracted into an undercarriage well for stowage and when an indication is given that the landing gear is fully stowed, a hydraulic actuator is operated to close the undercarriage well door until a catch member of the door cooperates with a latch of an uplock assembly to prevent the unintentional opening of the door(s) during flight.

Prior to landing, the uplock assembly needs to be released to permit the door to open and the landing gear to be lowered and extended. The release occurs by hydraulically-aided or other means and/or with the aid of gravity. Therefore, an uplock release assembly is a device which allows an uplock assembly to go from a locked and closed position to an unlocked and opened position. Moreover, the normal uplock release assembly is referred to as the primary uplock release assembly as opposed to an alternate uplock release assembly.

Back-up or emergency systems are also standard with uplock assemblies. For ease of language, a back-up or emergency release system will referred to as an alternative uplock release assembly. In the event the primary uplock release assembly should fail, an alternate unlocking means is required. For example, in order to lower the landing gear manually, the primary uplock release assembly can be bypassed. One way to achieve this is through the release of hydraulic fluid allowing the landing gear to move to the extended position. Other alternate assemblies such as disclosed in U.S. Patent No. 6,027,070 to Zambelli use mechanical systems with cables and pulleys for sequential release of the door uplock assembly followed by release of the landing gear uplock assemblies. This particular system is mechanically complex, cumbersome and is implemented when more than one uplock needs to be actuated sequentially by some alternate means.

U.S. Patent No. 6,802,476 to Collet et al. discloses an alternative system comprising a first or primary actuator (eg. a motor) for normal mode operation and a second actuator for emergency operation which can enable the high torque required to unlock the hook while the assembly is under load. However, if numerous uplock assemblies are required in the in the aircraft, the inclusion of a separate actuator for each uplock assembly results in a heavier and more cumbersome alternate release system.

There is therefore a need to provide a mechanically more simple and more reliable alternative uplock release assembly for an uplock assembly which is not as complex or heavy as the systems discussed above.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a new alternative uplock release assembly comprising: a pivot pin having a first end and a second end and an internal bore, a release system operatively connected to the first end of the pivot pin, said release system comprising a cylinder and a piston, said piston having a piston head and an elongated member passing longitudinally through said bore, said cylinder having a pressure port through which a pressure source can be fed, a hooking member, a torque member rotatably mounted at the second end of the pivot pin, a biasing system operatively connected to the torque member, said biasing system having a bias cylinder and a biasing means located within the bias cylinder, wherein biasing force is applied to the torque member, an interlocking means to

enable the rotatable interconnection between the torque member and the hooking member in a locked and first position, and an engaging means to interconnect the torque member with a link member, wherein when torque is applied to the link member, the torque is transferred, via the engaging means and interlocking means, to the hooking member forcing the hooking member to rotate around the pivot pin and wherein when pressure is fed through the pressure port, the piston counteracts the biasing force, thereby translating the torque member longitudinally over the pivot pin sufficiently to decouple the torque member and the hooking member from the said locked and first position, to an unlocked and second position enabling the hooking member to rotate around the pivot pin.

A further object of the present invention is to provide an alternate method for releasing a locked uplock assembly comprising a pivot pin having a first end, a second end and an internal bore, a release system operatively connected to the first end of the pivot pin, said release system comprising a cylinder and a piston, said piston having a piston head and an elongated member passing longitudinally through said bore, said cylinder having a pressure port through which a pressure source can be fed, a hooking member, a torque member rotatably mounted at the second end of the pivot pin, a biasing system operatively connected to the torque member, said biasing system having a bias cylinder and a biasing means located within the bias cylinder, wherein biasing force is applied to the torque member, an interlocking means to enable the rotatable interconnection between the torque member and the hooking member in a locked and first position, and an engaging means to interconnect the torque member with a link member, comprising the steps of: feeding pressure through the pressure port, counteracting the biasing force, translating the torque member longitudinally over the pivot pin, away from the hooking member, decoupling the torque member and hooking member, and allowing the hooking member to rotate around the pivot pin from the locked and first position to an unlocked and second position.

Yet a further object of the present invention is to provide an uplock release assembly and method of use in which the assembly comprises both a primary release as well as an alternative release as evidenced in the figures and description to follow.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a cut-out view of one embodiment of the hook release assembly according to the present invention.

Figure 2 shows a perspective view showing the inner disposition of the connection means and the interlocking means of the embodiment in Figure 1 in a locked and first position.

Figure 3 shows an exploded view of the embodiment in Figure 1.

Figure 4 shows a cut-out view of the embodiment in Figure 1 in which the torque member is coupled with the hook member in the first position in a locked and first position.

Figure 5 shows a cut-out view of the embodiment in Figure 1. in which the torque member is de-coupled from the hook member in the unlocked and second position.

Figure 6 shows a cut-out view of the embodiment in Figure 1. in which the torque member is de-coupled from the hook member in the unlocked and second position and the hook member is rotated around the pivot pin.

Figure 7 shows a cut-out side view of a lifting uplock assembly incorporating the embodiment in Figure 1.

Figure 8 illustrates a side view of an uplock assembly incorporating one embodiment of the hook release assembly according to the present invention, wherein the uplock is closed and locked.

Figure 9 illustrates a side view of the embodiment of Figure 8 wherein the uplock is opened.

Figure 10 illustrates a side internal view of the embodiment of Figure 8 wherein the uplock is closed and locked.

Figure 11 illustrates a side view of a non-lifting uplock assembly capable of incorporating one embodiment of the hook release assembly according to the present invention.

Figure 12 illustrates a perspective view of an uplock assembly incorporating one embodiment of the hook release assembly according to the present invention.

Figure 13 is a cross-section view of another embodiment of the hook release assembly according to the present invention in a locked and first position.

Figure 14 is a perspective exploded view of the embodiment illustrated in Figure 13.

Figure 15 is a cross-section view of the embodiment illustrated in Figure 13 during normal mode of operation of the uplock in a locked and first position.

Figure 16 is a cross-section view of the embodiment illustrated in Figure 13 during alternate release operation of the uplock in an unlocked and second position.

Figure 17 depicts a shear cartridge as used in one embodiment of the present invention.

Figure 18 depicts a bias cylinder as used in one embodiment of the present invention.

Figure 19 depicts a torque member as used in one embodiment of the present invention showing torque member projections.

Figure 20 depicts a link member as used in one embodiment of the present invention.

Figure 21 depicts a hooking member as used in one embodiment of the present invention showing hooking member projections.

Figure 22 depicts a support link as used in one embodiment of the present invention.

Figure 23 depicts a pivot pin as used in one embodiment of the present invention.

Figure 24 depicts a piston cylinder as used in one embodiment of the present invention.

Figure 25 depicts a thrust bearing as used in one embodiment of the present invention.

Figure 26 depicts a piston as used in one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The present invention provides a new alternative uplock release assembly for release of a hooking member 10 from an uplock assembly 2, that can be used, for example, during an emergency or following a failure of the primary uplock assembly release assembly during the normal mode of operation. The alternative hook release assembly comprises a pivot pin 20 having a first end 22 and a second end 24, a release system 65, a hooking member 10, a torque member 30 rotatably mounted at the second end 24 of the pivot pin 20, a link member 40 and a biasing system 50. The hooking member 10 and the torque member 30 include an interlocking means 60 enabling the rotatable interconnection between the hooking member 10 and a torque member 30 in a locked and first position. The torque member 30 further includes an engaging means 32 to interconnect the torque member 30 with a link member 40 such that when torque is applied to the link member 40, the force is translated, via the engaging means 32 and interlocking means 60, to the hooking member 10 allowing the hooking member 10 to rotate around the pivot pin 20. A biasing system 50 is operatively coupled to the torque member 10. The biasing system 50 includes a bias cylinder 52 housing and a biasing means 54 located within the bias cylinder 52 housing to bias the torque member 30 in a locked and first position with the hooking member 30. A release system 65 is operatively connected to the first end 22 of the pivot pin 20. The release system 65 includes a piston cylinder 70 and a piston 72. The piston 72 further comprises a piston head 74 at one end and an elongated member 76 which extends longitudinally through an internal bore 78 in the pivot pin 20. During operation of the alternate uplock release assembly, the pivot pin 20 is operatively connected with the torque member 30 such that when sufficient pressure is fed into the piston cylinder 70, the piston 72 moves longitudinally towards the opposite end of the assembly and counteracts the force applied by the biasing means 54. The torque member 30 moves longitudinally away from the hooking member 10, thereby decoupling the torque member 30 from the hooking member 10 from a locked and first position to an unlocked and second position. In the second position, the hooking member 10

is able to rotate around the pivot pin 20 since it is not fixed in place by the torque member 30. When pressure against the piston 72 is decreased or stopped, the force applied by the biasing means 54 returns the torque member 30 towards the hooking member 10.

It would be understood by a worker skilled in the art that the various components of the alternative uplock release assembly can be formed from one or more metals, alloys and/or ceramics, including, but not limited to, steel, stainless steel, aluminum and titanium or any combination thereof and the outside diameter of the various components may be lined with a low friction metal, alloy or ceramic.

Figures 1 to 7 depict various views of one embodiment according to the present invention. Figure 1 illustrates a cross-sectional view of an alternate uplock release assembly according to one embodiment of the present invention. The alternate uplock release assembly includes a pivot pin 20, a release system 65, a hooking member 10, a torque member 30, a biasing system 50 and a link member 40.

Pivot Pin

Figures 1 and 2 show a release assembly comprising a cylindrical pivot pin 20 longitudinally disposed along a pivot axis A. The pivot pin 20 includes a first end 22, a second end 24, and an internal bore 78 extending there-through from the first end 22 to the second end 24. The internal bore 78 is centrally located within the pivot pin 20. The pivot pin 20 further includes a means to engage with the release system 65, such as, according to one embodiment of the present invention, a plane annular flange 90 located proximate the first end 22 of the pivot pin 20.

Release System

As illustrated, for example in Figures 1 to 6, the release system 65 according to an embodiment of the present invention includes a piston 72 having a piston head 74 which is received in a piston cylinder 70. The piston cylinder 70 further includes a pressure port 80 (see Figures 2 and 3), and a means for receiving the pivot pin 20, such as, according to one embodiment of the present invention, a recessed annular ridge 75 along the circumference of the opening of the piston cylinder 70 (see Figure 1). The piston 72 further includes an

elongated member 76 passing through the internal bore 78 of the pivot pin 20, wherein said elongated member 76 is capable of translating longitudinally within said pivot pin internal bore 78. The elongated member 76 includes, at the end opposite to the piston head 74, a piston stud 77 which is positioned within the torque member aperture 33 (see Figures 1 and 26).

The piston cylinder 70 may further comprise a mounting flange 100 (Figures 1, 2 and 3) extending radially outwards from the opening of the piston cylinder 70. The mounting flange 100 further includes mounting apertures 102 wherein fastening devices such as mounting bolts 104 (see Figure 3), may be used to mount the piston cylinder 70 to the uplock assembly. Other fastening devices, including but not limited to, rivets, pins or other traditional devices may also be used to mount the piston cylinder 70 to the uplock assembly 2. In an alternative embodiment of the present invention, the piston cylinder 70 can be integrally formed with an uplock assembly housing 5. The piston cylinder 70 is not limited to a cylindrical shape, but rather can be of any shape or configuration which would allow to fulfill the utility explained herein. Correspondingly, piston head 74 is not limited to a circular shape.

In yet a further alternative embodiment, the present invention comprises an overall integrated assembly where the alternative uplock release assembly and the primary uplock release assembly are combined into one assembly. This integration of alternative and primary assemblies results in a functional combination that is an improvement over other assemblies that operate in a non-synergistic manner. The primary release assembly and the alternative release assembly are integrated to work in a complementary fashion. Should the primary assembly not function properly, the alternative uplock release assembly overrides the primary assembly link between the linking member 40 and the hooking member 10 to achieve the desired release. This complementary integration is well illustrated and described below.

Hooking Member

The hooking member 10 comprises a mounting end 14 and a hook 12 (Figures 3, 4 and 5). The mounting end 14 comprises a first lateral surface, a second lateral surface 17 and an aperture 18 (Figures 3 and 21). The second lateral surface 17 further comprises an interlocking means 60 (Figure 2) to rotationally and releasably interconnect the hooking member 10 with the torque member 30.

In one embodiment of the present invention, the interlocking means 60 is comprised of two or more hooking member projections 19 associated with the second lateral surface 17 surrounding the aperture 18, which are designed to complementarity mate with two or more torque member projections 35 (Figures 3 to 6).

In another embodiment (not shown) of the present invention, the projections of each member (hooking member projections 19 and torque member projections 35) may be angled so as to facilitate engagement with the respective projections of the other and to minimize free play between these respective projections. Other configurations wherein the hooking member 10 and the torque member 30 can releasably and complementarily mate are also contemplated.

The hooking member 10 rotationally mounts onto the pivot pin 20 (Figures 1 and 3) via the aperture 18 and, in a decoupled position, is capable of independent rotation around axis A (Figures 1 and 2). A stop means positioned proximate to the hooking member 10 can limit the degree of rotation of the hooking member 12 to a desired amount. In one embodiment of the present invention, the stop means can be an actuating end 42 of the link member 40.

In a further embodiment of the present invention, the hooking member 10 comprises a plurality of hooks 12. A worker skilled in the art would understand that a plurality of hooks might add stability and strength to the uplock assembly 2.

Torque Member

As shown in Figure 19, the torque member 30 comprises a cylinder having a first end, second end, and an internal bore 31 at the first end wherein the torque member internal bore 31 extends longitudinally the length of the torque member 30 to the second end of the torque member 30 for translationally connecting with the pivot pin 20. The torque member 30 further comprises a means to matingly interlock or couple with the projections 19 of the hooking member 10, thereby providing a means for rotational interconnection. In one embodiment of the present invention, the means to interlock comprises one or more torque member projections 35 extending along axis A (Figures 1 and 2) to form a rotational interlock with the hooking member projections 19, thereby creating an interlocking means 60 (Figure 2).

The outer circumference of the cylinder wall of the torque member 30 further comprises an engaging means 32 to slidably connect and rotationally interlock with the link member 40. In one embodiment of the present invention, the connection means is provided by one or more keys 34 on the torque member 30 which can matingly connect to one or more keyways 36 formed in the link member 40 (Figure 3). In one embodiment the engaging means 32 comprises a plurality of radially positioned trapezoidal ridges around axis A (Figures 1 and 2) which extend outwardly from the outer circumference of the cylinder wall of the torque member 30.

The torque member 30 is mounted proximate to the second end 24 of the pivot pin 20 and receives said pivot pin 20 within the torque member internal bore 31, wherein the torque member 30 is capable of sliding along and, independently, rotating around axis A (Figures 1 and 2).

Biasing System

The biasing system 50 includes a biasing means 54 disposed within a bias cylinder 52. The bias cylinder 52 includes an opening at one end to bias the torque member 30 into a coupled position with the hooking member 10. The biasing means 54 can be any device with resilient means, for example, one or more metal springs, elastomer springs, Belleville™ washers, concentric compression return springs, detent mechanisms or any other suitable device that achieves this same means.

In a first coupled position, the torque member 30 is biased into an interlocked orientation with the hooking member 10 such that the torque member 30 and the hooking member 10 are rotationally coupled. In the first coupled position (during normal operation), torque applied to the link member 40 will transfer via the engaging means 32 and the interlocking means 60 to rotate the hooking member 10 interlocked to the torque member 30 around axis A (Figures 1 and 2).

The bias cylinder 52 (Figures 1 to 7, and 18) may further comprise a mounting flange 101 extending radially outwards from the opening of the bias cylinder 52. The mounting flange 101 further includes mounting apertures 103 wherein fastening devices such as mounting

bolts 104 (Figures 3 and 7), may be used to mount the bias cylinder 52 to the uplock assembly 2. Other fastening devices, including but not limited to, rivets, pins or other traditional means may also be used to mount the bias cylinder 52 to the uplock assembly 2.

When both the bias cylinder 52 and the piston cylinder 70 are mounted to the uplock assembly 2, the pivot pin 22 is secured from any translational movement along axis A (Figures 1 and 2).

In one embodiment of the present invention (Figures 1 to 7), a first flange bushing 110 is mounted on the uplock assembly housing 5 to receive the pivot pin 20 proximate to its first end 22. One or more spacers 114 can be mounted between the first flange bushing 110 and the hooking member 10. A second bushing 112 is mounted on the uplock assembly housing 5 to receive the torque member 30 proximate to its second end between the link member 40 and the biasing system 50.

The bias cylinder 52 is not limited to a cylindrical shape, but rather can be of any shape or configuration which would allow to fulfill its utility as explained herein. Correspondingly, biasing means 54 is not limited to a circular shape.

Link Member

The link member 40 links the alternative uplock release assembly to an actuating means 43 of the uplock assembly 2 (Figure 7). The link member 40 can take many shapes or designs depending on the design of the uplock assembly 2 and size constraints or requirements, as long as it provides a linking means. Generally, the link member 40 comprises a link member actuating end 42 and an opposite torque member end 44 (see Figures 2, 3, 4 and 20). The torque member end 44 comprises an engaging means 32 (Figures 1 and 2) to slidably connect and rotationally interlock with the torque member 30. In one embodiment, illustrated in Figure 3, the engaging means 32 is provided by one or more link member keyways 36 that mate with the one or more torque member keys 34 -located on the torque member 30. In another embodiment shown at Figure 20, the keyways 36 have an alternate configuration which mates with the corresponding torque member keys 34 of an alternatively configured torque member 30.

In one embodiment of the present invention, the means to slidably connect with the torque member 30 includes an annular aperture having a plurality of radially formed trapezoidal ridges on its inner circumference which can mate with the trapezoidal ridges on the torque member 30 to form a rotational interlock capable of providing translational movement.

In another embodiment of the present invention, the actuating end 42 comprises a means to pivotally connect the link member 40 to the uplock actuating means 43 of the uplock assembly 2.

In one embodiment of the present invention, a pivotal connection means is an aperture for receiving a pivotal connection 46 (Figure 7), for example, but not limited to, a pin, bolt or stud.

Operation

Upon actuating, such as in an emergency situation that requires release of the uplock, pressurized fluid, for example, hydraulic fluid or pressurized air or other gas or liquids, is fed into the piston cylinder 70 to longitudinally move the piston head 74 within the piston cylinder 70 along axis A (Figures 1 and 2).

One embodiment of the present invention provides for an hydraulic pump that feeds hydraulic fluid into the piston cylinder 70 through the pressure port 80 (Figures 2 and 3), thereby moving the piston head 74. The piston 72 in turn, translationally engages with the torque member 30 thereby sliding the torque member 30 along the pivot pin 20 from a first coupled position shown in Figure 4 to a second decoupled position shown in Figure 5, thereby decoupling the mating interlocking means 35 of the torque member 30 from the interlocking means 19 of the hooking member 10, and allowing the hooking member 10 to rotate freely. It would be understood by one of ordinary skill in the art to which this invention belongs that, in order to decouple the torque member 30 from the hooking member 10, the force required to act on the piston head 74 must be greater than and opposite to the force applied to the torque member 30 by the biasing means 54 in addition to any frictional or other resistance, otherwise longitudinal movement of the torque member 30 would not occur. Once the torque member 30 and the hooking member 10 are decoupled, the hooking member 10 is allowed to rotate around axis A into an unlocked position, independent of the uplock

assembly 2, as shown in Figure 6. In an embodiment, the weight of the hooking member 10 is sufficient to allow the hooking member 10 to rotate around axis A.

Other embodiments of the present invention can use different translational pressure sources to cause the piston 72 to translationally engage with the torque member 30 thereby sliding the torque member 30 along the pivot pin 20 from a first coupled position to a second decoupled position. Such translational pressure sources may be activated by means including but not limited to hydraulic, pneumatic, chemical (exothermic or endothermic), magnetic, mechanical (automatically or manually activated) and electromechanical means. An exothermic chemical means could involve and explosive chemical reaction to push the piston 72 and an endothermic means could involve a contracting chemical reaction to pull the piston 72.

The bias force from the biasing means 54 automatically moves the torque member 30 into the first position to recouple the torque member 30 and the hooking member 10 when there is a decrease in pressure such as when the pressurized fluid is released from the pressure port 80 and the hooking member projections 19 and the mating torque member projections 35 are aligned. The mating hooking member projections 19 of the hooking member 10 can be recoupled to the mating torque member projections 35 of the torque member 30 by repositioning or rotating the hooking member, for example through manual movement of the hooking member 10 into a mating position. There are alternate ways for recoupling the hooking means and the torque member 30 that would be known to a worker skilled in the art to which the present invention belongs and such ways are incorporated herein.

Upon the decoupling of the hooking member 10 and the torque member 30, the hooking member 10 is urged into the unlocked position, through rotation around the pivot pin 20. This urging of the hooking member 10 can be provided by a door preload, for example, where the door associated with the uplock assembly 2 is spring-loaded against its frame, thereby forcing the hooking member 10 into the unlocked position once it is allowed to rotate around the pivot pin 20. Alternatively, gravitational force or a second biasing system associated with hooking member 10 could assist the rotation of hooking member 10 around the pivot pin 20.

In an embodiment, upon decoupling of the hooking member 10 from the torque member 30, the hooking member 30 may rotate around the pivot pin 20 to the unlocked position based on the force of gravity and, as such, the optimum orientation for the alternate uplock release assembly is for axis A to be substantially perpendicular to the force of gravity.

It would be appreciated by one skilled in the art that bushings 110, 112, spacers 114, bearings 116 and/or washers 118 may be added to support, guide, or align any of the components of the present invention. A combination of such devices can be used at different locations throughout the alternate uplock release assembly to also minimize operational interference and surface wear between components, without departing from the present description of the invention.

The alternative uplock release assembly can be integrated within the uplock assembly 2 or, alternatively, it can be complementarily adapted to an existing uplock assembly 2.

In reference now to Figures 8 to 12, other embodiments of the present invention incorporated in various uplock assemblies are disclosed.

Figure 8 illustrates a side view of an uplock assembly 2 incorporating one embodiment of the alternative uplock release assembly, wherein the hooking member 10 is in a locked and first position. Figure 9 illustrates a side view of the embodiment of Figure 8 wherein the hooking member 10 is in a second opened position. Figure 10 illustrates a side internal view of the embodiment of Figure 8 , wherein the hooking member 10 is in a locked and first position.

Figure 11 illustrates a side view of a non-lifting uplock assembly 2 capable of incorporating one embodiment of the alternative uplock release assembly according to the present invention.

Figure 12 illustrates a perspective view of an uplock assembly 2 incorporating one embodiment of the alternate uplock release assembly according to the present invention. The embodiment represented in Figure 12 shows the relative positioning of the uplock assembly 2 and components of the alternate uplock release assembly such as the hooking member 10, the hook 12, the hydraulic pressure port 80, the bias cylinder 52, the mounting flange 101, the mounting bolts 104 and an optional shear cartridge 125. The shear cartridge 125, also shown

at Figure 17, is provided to offer increased protection against a potential sudden increase in the pressure through the pressure port 80 which would tend to extend the piston 72. The shear cartridge 125 comprises a shear pin sized to resist the maximum pressure spike condition. When the alternative uplock assembly is effected, the shear cartridge 125 needs to be replaced with a new one before future use can occur if the pressure exceeded the maximum pressure associated with the shear pin. The alternative uplock release assembly is located at the pivot point of the hooking member 10 and is mounted externally on the side of the uplock assembly 2, facilitating the shear cartridge 125 replacement.

Figures 13 to 16 illustrate another embodiment of the alternative uplock release assembly according to the present invention. The alternative uplock release assembly is comprised of a torque member 30 engaging into a lateral surface 17 of the hooking member 10 and sliding inside a link member 40. The torque member 30 incorporates a set of torque member projections 35 serving a dual purpose; it allows the torque member 30 to engage a set of complementary hooking member projections 19 on the lateral surface 17 of the hooking member 10 allowing the torque member 30 to become operatively connected to the link member 40 and to slide inside the link member 40. A support link 41 can be incorporated to add further support against loads encountered during the normal operation of the uplock and to avoid detrimental deflections of components of the alternative uplock release assembly.

During normal operation of the uplock, the torque member 30 is maintained in its extended position by the two concentric compression return springs (inner return spring 55 and outer return spring 56) with its torque member projections 35 engaging the hooking member projections 19. This allows the uplock assembly internal mechanism connecting to the link member 40 to drive the hooking member 10 open or close around the hook pivot pin 22 during normal operation of the uplock. The relative position X of the piston head 74 in said normal operation is illustrated in Figure 15.

During an emergency operation of the uplock, the piston cylinder 70 is pressurized by the pressure source fed through the pressure port 80, thus forcing the piston 72 to move the torque member 30 against two concentric compression return springs (inner return spring 55 and outer return spring 56). This is in effect disengaging the torque member 30 from the hooking member 10 allowing it to rotate freely around the hook pivot pin 22 thus by-passing any condition which might be preventing the uplock to open under its normal mode of

operation. The relative position X of the piston head 74 in said emergency operation is illustrated in Figure 16.

The piston cylinder 70 incorporates a pressure port 80 depicted as a beam seal type fitting AS 1986-04. Other types of pressure ports could alternatively be used depending on the hydraulic or other connections used with the alternate uplock release assembly. The piston cylinder 70 is mounted onto the side of the uplock housing and retained with three standard bolts. The piston 72 can incorporate a lightning hole at one end and a groove on the piston head 74 outside diameter to allow for the installation of an elastomeric seal 73 compatible with the type of hydraulic fluid (or other substance used to pressurize the piston 72) used with the alternate uplock release assembly.

The bias cylinder 52 incorporates a pair of concentric compression return springs (55, 56) to provide a pre-load force maintaining the torque member 30 engaged with the hooking member 10. The compression return springs (55, 56) are sitting against a thrust bearing 116 to allow for free rotation of the torque member 30 during normal uplock operation. In addition to the compression return springs (55, 56), a shear cartridge 125 is provided to offer increased protection against a potential pressure spike in the pressure source, which would tend to extend the piston 72. The shear cartridge 125 comprises a shear pin sized to resist the worst case pressure spike condition. In the event that an alternate release of the uplock is activated, the shear cartridge 125 needs to be replaced before the next alternate release of the uplock.

The uplock housing 5 is fitted with a pair of flange bushings 110 composed of a suitable alloy such as an aluminum-nickel-bronze alloy, to minimize wear and friction. The hook pivot pin 22 is made of a high strength steel alloy and is coated with a self-lubricant Teflon™ based liner to minimize wear and friction. Other known self-lubricant materials can also be used. The torque member 30 is made of a high strength bronze alloy offering good wear characteristics and a low coefficient of friction. During normal operation of the uplock, the torque member 30 rotates inside the flange bushing 110 with the rotation of the hooking member 10. During an alternate release of the uplock, torque member 30 longitudinally translates inside the same flange bushing 110 to compress the two return springs (55, 56). It would be understood by a worker skilled in. the art that many other materials and alloys,

sharing similar characteristics, could also be used to make the aforementioned components without departing from the scope of the present invention.

A series of washers 118 can be used at different locations in the alternate uplock release assembly to control running clearances and minimize surface wear between various components thereof.

Once the alternative uplock release assembly has been activated and the hooking member 10 allowed to rotate open to release the door roller 130 (see for example Figure 9), the alternative uplock release assembly has the ability to reset itself either in-flight or on the ground by: 1) depressurizing the release system 65 and 2) conducting a normal opening of the uplock (after the failure condition preventing the normal mode to be used has been corrected). Once the torque member projections 35 are aligned with the hooking member projections 19, the torque member 30 will retract and re-engage under the load of the compression return spring (55, 56).

Figures 17 to 26 depict individual components of an embodiment of the alternate uplock release assembly according to the present invention. Figure 17 depicts a shear cartridge 125 as used in one embodiment of the present invention. The shear cartridge 125, operatively connected to the piston cylinder 70, is provided to offer increased protection against a potential pressure spike in the pressure source which would tend to extend the piston 72. Figure 18 depicts a bias cylinder 52 as used in one embodiment of the present invention. The bias cylinder 52 is operatively connected to and houses the biasing means 54. Figure 19 depicts a torque member 30 as used in one embodiment of the present invention. The torque member 30 has torque member projections 35 and its functionality has been previously explained in the description of various embodiments of the present invention above. Figure 20 depicts a link member 40 as used in one embodiment of the present invention. The link member 40 comprises a link member actuating end 42 and link member keyways 36; its functionality has been previously explained in the description of various embodiments of the present invention above. Figure 21 depicts a hooking member 10 as used in one embodiment of the present invention. The hooking member 10 comprises a hook 12 and hooking member projections 19; its functionality has been previously explained in the description of various embodiments of the present invention above. Figure 22 depicts a support link 41 as used in one embodiment of the present invention its utility is explained in the description of various

embodiments of the present invention above. Figure 23 depicts a pivot pin 22 as used in one embodiment of the present invention and as described above. Figure 24 depicts a piston cylinder 70 as used in one embodiment of the present invention. The piston cylinder 70 comprises mounting flange 100, mounting apertures 102 and a pressure port 80; its functionality has been previously explained in the description of various embodiments of the present invention above. Figure 25 depicts a thrust bearing 116 as used in one embodiment of the present invention and described above. Figure 26 depicts a piston 72 as used in one embodiment of the present invention. The piston 72 comprises a piston head 74 an elongated member 76 and a piston stud 77; its functionality has been previously explained in the description of various embodiments of the present invention above.

Thus it can be appreciated by a worker skilled in the art that the compact nature of the alternate uplock release assembly according to the present invention renders it useful and adaptable to almost any uplock assembly design where it is required to have an emergency release, for example, for aircraft landing gears, emergency or service doors. The device is also easily adaptable for use in any other application where an uplock assembly and an alternative release assembly are required is provided.

The embodiments of the invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.