Abstract: A safety curtain rail comprises a curtain rail suspended by connectable and disconnectable joints, each comprising a plug and socket. Each joint comprises a plug (40), a socket (10), the plug being provided with an engagement portion (43) and the socket comprising a tubular bore (20), the engagement portion fitting into the tubular bore. Between the engagement portion and the bore is provided a resilient ring (51). The relative dimensions of the engagement portion, socket and resilient ring and the flexibility of the ring are selected such that the plug can disconnect from the socket under a predetermined force in a direction pulling the plug apart from the socket.

Abstract: A thermally released separation or disconnecting device, particularly for fire protection systems, includes two oppositely arranged joining members which are connected to each other and are subjected to a tensile force. A destructible thermal release element is held between the joining members. The joining members are constructed as stirrups with two legs each, wherein the stirrups equally absorb the tensile force. The destructible thermal release element is held between oppositely arranged legs of the stirrups and extends essentially perpendicularly of the direction of the tensile force in the locked position of the separation device. Each leg of one stirrup holding the thermal release element is connected in the locked position of the separation device to the other leg of the other stirrup in a positively engaging manner against the direction of the tensile force.

Abstract: A device for releasing of a frozen screw pressed against a contact surface uses a compression disc pre-loaded to an anticipated amount of deflection prior to mounting between the contact surface and the screw. The disc has an insert formed from a granulated material mixed with a water soluble binder, allowing to wash out the insert and cause collapse of the disc, so as to break the connection between the contact surface and the screw.

Abstract: An anchor plate (2) mounted on the outside (15) of an inner vehicle body panel (8) having an elongate member with first, second and third holes (22,24,26) aligned on the plate (2), the second hole (22) being disposed between the first and third holes (24,26), and closer to the first hole (24) the third hole (26), the first hole (24) being directed to the front of the vehicle and the third hole (26) being directed to the rear of the vehicle. First, second and third nuts (32,34,36) are aligned with the first, second and third holes (22,24,26), respectively, for receiving respective bolts and screws (16,18,20) which fix the anchor plate (2) to the inner vehicle body panel (8).

Abstract: A connection between a collapsible mast jacket of an energy-absorbing steering column and a body of a motor vehicle including an outboard mounting bracket on the mast jacket having a pair of lateral flanges, a pair of open slots in the lateral flanges each having a pair of side edges interrupted by a plurality of evenly-spaced notches, a pair of capsules in the open slots rigidly clamped to the vehicle body, and a plurality of equally-spaced plastic shear pins on the capsules seated in the notches to couple the capsules to the outboard mounting bracket. Each capsule includes a capsule base having the plastic pins thereon and a separate capsule cover. The linear pitch between the plastic shear pins is the same as the linear pitch between the notches.

Abstract: A lawn mower having a rotation drive connection assembly including a reel shaft having concially shaped opposite ends and an interior threaded length in each of the opposite ends. A drive coupler with a conical shape on one end thereof mates with one of the reel conical ends and has a threaded opening for receiving a screw extending into the shaft for holding the coupler thereon. A spline is on the end of the coupler opposite its one end, and there a drive member with a spline engaged with the coupler spline, all for rotating the shaft. A counter-balance is threadedly attached in the assembly adjacent the end of the shaft opposite the coupler location.

Abstract: A sign post is formed of a lower support component for anchoring within terrain, leaving an exposed upper portion at the surface of such terrain. The support component includes an array of longitudinally regularly spaced apertures. An upper support component having the same regular spacing of apertures is attached to the lower component at the exposed portion through the utilization of a splicing technique. The splice is formed as a stress transfer component having two strategically positioned boltways therein. These boltways are spaced apart longitudinally a distance representing an even integer of the upper and lower component aperture spacings. The boltways are configured having a small threaded region adjacent one surface. Bolts having a threadless shank and threaded region therebelow are slidably inserted through one of the components into the stress transfer whereupon they are rotated for preassembly engagement with the minor threaded regions of the stress transfer component.

Abstract: A mechanical safety breaker for disengaging a mechanical connection between two mechanical members at a time when a force transmitted through the connection of the two members exceeds a predetermined value is provided by employing an overload breaker element made of a ceramic. A ceramic breaker element provides a long time stabilized fracture performance particularly when the load applied thereto is of a repetitive nature.

Abstract: A collapsible post structure having a frangible region that allows the post to collapse when the latter is struck. The post structure includes an elongated anchoring member. The anchoring member having an anchoring member hollow section that extends longitudinally into one longitudinal end thereof and defining an anchoring member inner surface. The post structure also includes an elongated supporting member. The supporting member having a supporting member hollow section that extends longitudinally into one longitudinal end thereof and defining a supporting member inner surface. The post structure further includes a connecting component, the connecting component having a connecting component first section and a connecting component second section. The connecting component first section and the connecting component second section are configured and sized so as to be respectively insertable into the anchoring member hollow section and the supporting member hollow section.

Abstract: A breakaway mounting system for mounting a structure to a fixed support surface has a plurality of elongated mounting members extending generally perpendicular to the support surface. An attachment plate is coupled with the structure to be mounted. The attachment plate has a plurality of apertures formed therein, and each of the mounting members extends through one of the apertures. A plurality of shearing plates are provided. Each shearing plate generally surrounds one of the mounting members and is positioned between the support surface and the attachment plate. Each shearing plate has an upper surface and a lower surface. The area of the shearing plate upper surface is substantially smaller than the area of a lower surface of the attachment plate, and the area of the shearing plate lower surface is substantially smaller than the area of the support surface. A fastener is attached to the mounting member for securing the attachment plate to the support surface.

Abstract: A pair of sprockets for use in a double chain and sprocket coupling for transmission of torque between shafts which are in approximate axial alignment with each other, and the abutting ends of which are closely spaced. Each of the sprockets is formed as one piece, and then cut into halves but for a web which is broken to separate the halve. The broken web serves to properly align and space the halves when placed over the end of a shaft to be coupled, and clamped thereon.

Abstract: A casing for use in the manufacture of a resilient joint, the casing having an outer surface and an inner surface, the inner surface defining an internal cavity, wherein the casing has at least one frangible wall section which is adapted to fracture upon the application of a compressive force to the outer surface of the casing such that after such fracture the volume of the internal cavity of the casing is reduced.

Abstract: Deflection slide clip of two piece construction for use in curtain wall construction providing for horizontal support of a laterally loaded stud while it accommodates vertical slip of the primary frame.

Abstract: A new overload protection device has been invented of the type in which components are fixed mutually by means of a safety member adapted to be cut or broken when the components are subjected to an overload, wherein the safety member is a thread spiral or spirals adapted to be cut loose from a member, rod or sleeve when the thread spiral (or spirals) is subjected to an overload.

Abstract: An airbag module has a generator carrier (11) which is to be secured to a vehicle component and on which or in which there is arranged a generator (12) and also an inflatable gas bag (20) which is enclosed within a housing (13) closed on all sides. The housing (13) consists of two housing halves (14, 15) which are hingedly connected together and which are connected to one another by a two-member snap fastener (16,17). A separation of the two housing halves (14,15) can be effected by fracture of a desired fracture location (18) at the holding members (16,17) on triggering of the generator (12) and inflation of the gas bag (20).

Abstract: To secure containers on the floor of the cargo area of an aircraft, latches are known that comprise a frame and at least one latch hook, which is mounted on the frame so that it can pivot about an axle from a retracted resting position into an upright operating position. If due to inattentiveness of the service personnel the latch hook is left in its operating position and a container strikes against it while it is in this position, the result is often destruction of the floor structure. It is proposed to provide a safety device that allows the latch to be deflected out of the way when it is subjected to a predetermined overload in a direction parallel to the floor of the cargo area.

Abstract: A torque overload coupler for a driveline allows limited free motion. In one embodiment, torque overload protection is provided by a friction slip clutch and tangs formed at the inner perimeter of a clutch plate fit into spaces between lugs defined on a hub to provide a limited range of free motion. In another embodiment, torque overload is provided by a shear pin and free motion is provided by the shear pin fitting into angular spaces between wings of a relatively rotatable hub.

Abstract: A refrigerant compressor includes a drive shaft, a pulley fixedly fitted on the drive shaft, over which is passed a torque-transmitting member for transmitting torque from an external drive source to the drive shaft, and a compression rotational member mounted on the drive shaft for rotation in unison with the drive shaft to enable compression of a refrigerant gas. The pulley has a rim in the form of a hollow cylinder, over which is passed the torque-transmitting member, a boss which is fixedly fitted on the drive shaft, and a support member connecting the rim and the boss. A breakaway portion is provided in the support member or the drive shaft for breaking to disconnect the torque-transmitting member from the compression rotational member when a load torque larger than a predetermined value is applied to the breakaway portion.

Abstract: A sign post is formed of a lower support component for anchoring within terrain, leaving an exposed upper portion above the surface of such terrain. The support component includes an array of longitudinally regularly spaced apertures. An upper support component formed having the same cross-sectional configuration and regularly spaced apertures is attached to the lower component at the exposed portion through the utilization of a splicing technique. The splice is formed as a stress transfer bar having two strategically positioned bores therein. These bores are spaced apart longitudinally a distance representing an even integer of the upper and lower component aperture spacing. Breakaway bolts are positioned through one of the components and into and through the stress transfer bar, and then the second component is attached with nuts being positioned and tightened over the bolts as they extend through the stress transfer bar.

Abstract: A new Breakaway Sign Post Repair System for reusing a broken sign post thereby reducing the cost to repair the broken post while providing a breakaway post that will produce less damage to vehicles and people if a vehicle should hit the sign post. The inventive device includes a sign post cut into an upper post and a lower post, and a breakaway tube with a concentric horizontal partition forming an upper lumen and a lower lumen which capture the respective portion of the sign post, where the break away tube is constructed from a material that breaks concentrically.

Abstract: Thus, the present device provides a nut and bolt assembly having a lower threaded end and opposing upper threaded end. A first flange seats above the lower threaded end and an upper flange seats below the upper threaded end. A weak point having a known torque limit is provided below the upper flange. A nut is mounted on the upper threaded end. When the nut is turned beyond the torque limit of the weak point, it causes the bolt to break at the weak point. The bolt of the present invention is relatively inexpensive to make and use. It is designed preferably to be used in conjunction with a pressing member and a pipe junction holder for holding a pair of joined pipes.

Abstract: A post device, which is yieldable when hit by a vehicle, comprises a post with a base having at least three spaced-apart fixtures fixedly attached thereto, and a foundation with a fixing device supporting at least three spaced-apart rods, which are arranged to cooperate with the fixtures, thereby securing the post to the foundation. The fixtures are arranged on the outside of the base and embrace the associated rods and are each provided with a through opening or slot which is oriented substantially in the longitudinal direction of the post. Stop devices each engage an associated rod and an upper portion of an associated fixture.

Abstract: A controller (24) is provided to selectively release an initiator (12) having first and second members (14,16) that clampingly engage an object (18) preventing it from moving in an urged direction. A spring wire coil (20) holds the members (14,16) tightly about the object, one coil end affixed to one of the members and the other coil end is held by a pair of link wire loops (82,86) of the controller (24) which is also removably secured to one of the members (14,16) by a bolt (36). When it is desired to release the object (18) an electric current is passed through the link wire loops (82,86) of sufficient magnitude to cause the loops to break, releasing the coil (20) to unwind and, in turn, release the object for urged movement.

Abstract: A row cultivator (10) includes a row following system (12) coupled to a toolbar (13) employing frame members (17) and (18) constrained to remain parallel by a cross member (21). Coulter wheels (30) and (31) secured to the frame members (17) and (18) are non-steerable and tool bar drift may be corrected. A tool (40) employs a leading blade (44) and a pair of diverging cutting blades (47) and (48) trailing behind the leading blade (44). A sheer release assembly employs a longitudinally extending bolt (70) centrally disposed and holding a shank (61) to a tool bar (65) so that when a tool on the shank (61) strikes an underground obstacle the bolt (70) is sheared longitudinally.

Abstract: Deflection slide clip of two piece construction for use in curtain wall construction providing for horizontal support of a laterally loaded stud while it accommodates vertical slip of the primary frame.

Abstract: A system for holding together parts of a construction until the moment of separating the parts from each other, comprises at least two sections having abutting faces and tension element cooperating with supports, this tension element being provided on the sections holding the sections together under pre-tension. A breaker is provided for breaking the tension element so as to separate the sections. The tension element is wound around the supports forming a closed loop bundle that crosses the parting lines of the sections, whereby the strength of the bundle equals at least the pre-tension required to hold the sections together.

Abstract: A connector for plates, including a connector body having a base plate bent at its intermediate portion to form plate insert recesses and, and pin insert holes formed through the base plate; a pin member having a shaft portion and a head portion formed at one end of the shaft portion, the shaft portion having elastically deformable locking lugs, the other end portion of the shaft portion being inserted in at least one of the pin insert holes; and breakable connecting portions integrally formed between the other end portion of the shaft portion and the inner circumferential surface of the at least one pin insert hole, for connecting the pin member and the connector body. With this structure, the plates can be reliably connected and fixed together by the connector with a simple operation.

Abstract: A fastening system for securing structural members such as C-channels for buildings, bridges and the like and including a fastener construction for securing the structural members through spaced flanges or plates at locations where there is limited support between such flanges or plates with the fastener as installed having a member providing substantially direct, columnar support between the spaced flanges or plates.

Abstract: A vehicle seat assembly is provided with an energy absorption mechanism for dissipating energy in a high energy impact. The assembly includes a seat with a seat back totally connected thereto. The seat back includes a first support member pivotally connected with respect to the seat and a second support member pivotally connected to the first support member. An energy absorption mechanism is positioned between the first and second support members for dissipating energy as the second support member pivots with respect to the first support member. The energy absorption mechanism includes a plurality of adjustable shear pins having shearable cross-sections of various sizes to facilitate adjustment based upon the seat back angle. The shear pins are movable in a plurality of slots sequentially increasing in length such that the shear pins will sequentially shear to dissipate energy over time as the respective shear pins reach the end of their respective slots.

Abstract: A releasable connector for a pair of tensioned elements, such as straps sorting a parachuted load, has a cylindrical body separable at a diametrical plane into a pair of blocks each adapted for connection of the block to one of the elements. A helical groove is disposed about the body and is wound in one circumferential direction with the majority of an endless line of para-aramid fiber. The line is tensioned to hold the blocks in engagement so that the elements are joined by the connector. The ends of the groove return helically in the opposite circumferential direction, and the remainder of the line is wrapped in this opposite direction about the majority of the line. The body has a pair of recesses extending radially inwardly from the groove and individually receiving a pair of pyrotechnic line cutters. Each cutter extends into the groove and, at the groove, has an eye through which the line extends for severing by either cutter to release the blocks from engagement and disconnect the tensioned elements.

Abstract: A locking mechanism for releasably fixing an externally splined power take-off shaft to an output shaft of off-highway equipment such as a tractor. The output shaft has a hollow, internally splined hub portion adapted to axially receive the externally splined power take-off shaft to prevent relative rotational movement between the power take-off and output shafts. The locking mechanism includes a locking member supported within a radial opening in the power-take off shaft so as to be radially movable between an outer locking position and an inner unlocking position. In the outer locking position, the locking member is engageable with a recess formed in the hub portion of the output shaft to prevent relative axial movement between the power take-off shaft and the output shaft. In the inner unlocking position, the locking member is disengaged from the recess in the output shaft to permit such relative axial movement.

Abstract: An unlockable connecting device between two objects is provided. The device includes a connecting member for connecting the objects when the device is in a connected state, and an elastic system for applying to the connecting member a tensile stress for breaking the connecting member when the device is in a separation state. The tensile stress is caused by expansion of the elastic system as a result of elastic resiliency of the elastic system.

Abstract: A device for connecting the ends of two aligned sections of a hollow drive shaft which are rotatable about a common axis has first and second coupling members for securing to the ends of the drive shaft sections. At least two shearable bolts or pins connect the coupling members for transmitting torque between the drive shaft sections during operation and are arranged for balanced rotation of the coupling members under high r.p.m. conditions. The bolts, and not the drive shaft, will shear when the coupling members are subjected to a predetermined overload condition. The coupling members also include an annular groove and a correspondingly shaped annular projection for maintaining the shaft sections in axial alignment upon shearing of the bolts, and a collar for preventing the collapse of the shaft sections by restricting axial movement of the coupling members upon shearing of the bolts.

Abstract: The coupler has, in several embodiments, a compliant-link having flexible or pivoted fingers that engage a groove in the inside of a lower link in at least three places. The groove appears much like a bearing race. The compliant-link is retained inside of an upper sleeve that is attached to an upward-extending post. The lower (engaging) link is attached to a downward-extending post. The fingers are able to disengage from the groove under spring action and thus a sufficient applied moment will cause disengagement. Disengagement does not cause anything to break. Assembly, or reassembly, of the coupler may be performed without extra parts or tools. In several of the embodiments, the decoupling moment may be manually adjusted using less moment than the resultant decoupling moment. The decoupling moment is essentially independent of azimuth. The coupler is particularly suited to being used with rural type mailboxes, and warehouse buffers and supports.

Abstract: The expansion dowel includes an expansion sleeve (1) and an expanding member (5). The expansion sleeve 1 is provided with a bore (2) tapering in the setting direction as well as with open ended longitudinal slots (3). The expanding member (5) has a blind bore (6) open towards the setting side and has a lug (7) projecting from same at its opposite end, wherein the cross-sections of lug (7) and blind bore (6) are matched in such a way to one another, that a rated break point or failure point is formed. The force dependent response of this rated break point leads to a force dependent expansion while maintaining the driving or advance travel (X).

Abstract: An apparatus for pumping molten metal is disclosed. The apparatus includes a submergible pump housing, a rotatable impeller disposed within the pump housing, an impeller shaft having one end coupled to the impeller and extending through an opening in the pump housing, a motor-driven rotating drive shaft and a coupling member engaging an end of the drive shaft and an opposite end of the impeller shaft and a shear pin extending between the coupling member and one of the drive shaft and impeller shaft thereby coupling the drive shaft and the impeller shaft. Preferably, the coupling member is a female coupling member having two shaft receiving openings receiving the drive shaft end and the second end of the impeller shaft and includes a pair of aligned transverse apertures. A graphite pin is inserted through the coupling member apertures and extends through a transverse bore near the end of the impeller shaft. The graphite pin is held in place by a wire wrapped around an outer periphery of the coupling.

Abstract: A breakaway connection device is provided which is particularly suited for use with residential electric service cables. This device is mounted between the service cable and the service pole and serves to disconnect the cable from the pole upon the application of a predetermined level of tension or force to the cable. That level of force is selected so that the service cable breaks away from the pole and de-energizes the conductive wires before the service cable would pull away from and damage the dwelling. This device includes an insulated sheath having therein two hollow wire receiving elements which are separably joined by a conductive insert, formed as a solid rod or threaded member.

Abstract: A link wire (20) arrangement for use in a non-explosive initiator (10) includes a link wire (20) received within a pair of tubes (24,26), each tube having its outer end formed into a loop (28) and its opposite end crimped (30) to physically and electrically secure the tubes to the included link wire (20). The tubes (24,26) are encapsulated within an insulating body (16).

Abstract: A mobile suspension arrangement having a central member adapted to frictionally hold in suspension extended wires having related clip members frictionally engaging the wire ends and hanging strings for suspending mobiles.

Abstract: The coupling device for coupling a cable of a sewer and drain cleaning machine to a cutting tool comprises a housing, a cable connecting mechanism for connecting the cable to the housing, a cutting tool connecting mechanism for rotatably connecting the cutting tool to the housing, and a breakable drive mechanism for driving the cutting tool when the cable and the housing are rotated and breaking when a predetermined amount of torque is applied between the housing and the cutting tool, the predetermined amount of torque being less than the amount of torque needed to break the cable.

Abstract: An apparatus for positioning a dowel within a concrete slab is disclose. The apparatus comprises a substantially planar mounting flange that is used to mount the apparatus onto a wooden form, and a dowel guide that extends perpendicularly from the plane of the mounting flange.Together, the mounting flange and the dowel guide define a dowel passage that is aligned with a corresponding hole in the wooden form. The dowel passage allows a dowel to be slipped through the apparatus and through the hole in the form, and to extend into the region where the slab is to be poured. The invention allows dowels to be properly and consistently aligned before and during the pouring of a concrete slab.

Abstract: The initiator (32) has a hollow spool housing (34) with sidewall slots (42,44) and within which is received a shaft (54) to be releasably retained. Spool segments (46,48) are placed within slots (42,44) and have parts extending into the housing bore (50) obstructingly engaging the shaft (54) preventing its removal. A spring coil (82) wound over the spool segments (46,48) holds them in place. Cartridge assembly (62) is releasably secured to the housing (34) and includes a link wire (72) for securing one end of the coil (82). The link wire (72) is destructible by passing an electric current therethrough exceeding a certain value.

Abstract: A two-part fastening system composed of an anchoring part (1) which is pressed into a fastening body (4) of hard-elastic synthetic material. The anchoring part (1) consists of a relatively soft synthetic material and is provided with a plurality of parallel ribs extending perpendicularly from a carrier plate 2. The fastening body (4) includes a pair of clamping walls (5) having several rows of pointed projections (9) spaced one over another. The ribs of the anchoring part are pressed into engagement with the pointed projections so that a high strength connection between the parts is generated.

Abstract: A bottle holder for an automobile. The bottle holder includes a cradle or similar structure for securing a bottle in a predetermined position, a clamp for securing the bottle holder inside the automobile, and a partially rigid neck connecting the clamp to the cradle. The neck includes a frangible joint which shears in the event of a collision. The cradle and bottle are thereby no longer bound near the feeding child. The frangible joint preferably comprises a prescored tube, which breaks along a predetermined circumferential inscribed line in a collision. The frangible joint is manually removable and installable to the neck, so that it can be renewed should it break. Optionally, a flaccid tether is provided to restrain the freed cradle and bottle from being thrown uncontrollably about the automobile cabin.

Abstract: A load limited connector that is calibrated to fail at a predetermined approximate tensile load. The connector includes a main body, within which a pin chamber is received, and a secondary body having a shaft that is releasably secured within the pin chamber. At least one breakaway pin, positioned in a pin passageway passing through the pin chamber and into the main body, secures the pin chamber within the main body. When the connector is subjected to tensile loading that exceeds the yielding point of the breakaway pin, failure of the pin occurs resulting in separation of the main body from the secondary body. A pair of torsion pins extend through the pin chamber into the main body to prevent rotation of the pin chamber relative to the main body.

Abstract: A bed system is provided which limits the inflation time of each of a plurality of ventilating air mattresses with the system to a predetermined time. Each mattress includes a fitting with a spring biased pin for actuating a pump switch when the mattress fitting is properly mated with a pump adapter thereby facilitating inflation of said mattress. The pump is programmed to deactivate at the predetermined time, and to remain deactive until the pump switch is reset. The pin is positioned and constructed to be mechanically rendered inoperable in the process of resetting the switch thereby preventing each mattress fitting from actuating the pump switch a second time.

Abstract: A single shear joint is provided which includes a conical ferrule establishing a nesting means of engagement with controlled embedment between a link and a mating component.

Abstract: The application describes a hydrostatic release device, suitable for releasing life-saving equipment carried on a ship or aircraft when the ship or aircraft sinks or ditches in the sea. A change in ambient pressure is detected by a pressure sensor which opens a liquid-filled chamber and thereby releases a hydrostatic pressure behind a reciprocable member. This reciprocable member then allows release of a release means. The release means can comprise a link prevented from longitudinal movement by an abutment and normally constrained against lateral movement by the reciprocable member. Thus removal of the reciprocable member away from the link enables transverse movement of the link clear of the fixed abutment. Such an arrangement provides a particularly simple and inexpensive release means.

Abstract: A clip (100) is provided that has a substantially tubular body member (50) and at least one and preferably two diametrically opposed, outwardly extending tabs (18 and 18') that first engage a side of a frame (6) having an opening (13) through which clip (100) is inserted about a threaded stud or bolt (4) such as a vehicular exhaust tail pipe and which are operative to bend and straighten as a nut (8) rotationally advances along stud or bolt (4) to engage an end (7) of clip (100) and urge clip (100) through opening (13) until nut (8) engages frame (6) to eliminate effect of joint loosening caused by exposure of tabs (18 and 18') to corrosive environments.

Abstract: Embodiments of a log bunk shear-pin system are shown and described, each embodiment including a shear-pin that engages a log bunk and prevents the bunk from swiveling when the truck is being loaded or unloaded, but that releases the bunk when the shear-pin is mistakenly left engaged during travel. The shear-pin shears, or otherwise comes apart, when the power of the log load or the turning tractor forces the bunk to swivel relative to the tractor or trailer. The preferred shear-pin comprises a shoulder pin and a pin cap connected with a threaded insert. When the forces of a swiveling bunk push on the pin cap and the shoulder pin sideways in opposite directions, the insert breaks. A new insert may then be easily installed into the undamaged pin cap and shoulder pin. Thus, the shear-pin prevents damage to the bunk-ears and only allows damage of an inexpensive and replaceable portion of the shear-pin.