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: The catch (1) includes a plate (2 ) and a block (3 ) slidably mounted on the plate, which is connected by a strip (20) to a handle (19) so that the block (3) can be slidably adjusted with respect to the plate (2) by pulling on the handle (19) whilst the plate (2) is held in position.The system includes such a catch, adapted so that the handle is accessible in a predetermined position in which the stop surfaces have to come together, and in which the remainder of the system is inaccessible.The method provides that the position of the stop surface (16) is adjusted by pulling on the handle (19) until the stop surface (16) on the catch is brought into contact with the stop surface with which it has to interact.

Abstract: Any improved break-away banner rod assembly (10) is provided which includes a fixture (12) adapted for coupling to an upright support surface (14) and having a laterally extending, slotted body (30), and a coupler (16) supported by the fixture (12) with a zone of weakness (42) therein. An elongated banner rod (18) is connected with coupler (16) and extends through the slot (34) of body (30). The body (30) captively retains the inner end (44) of rod (18) in the event of load-induced fracture of the coupler (16) at zone (42), and prevents significant downward movement of the rod (18). Preferably, the slot (34) permits movement of rod (18) through a restricted arc upon fracture of the coupler (16).

Abstract: A novel mechanical camper jack for mounting on a camper body is disclosed. The jack has an outer jack housing, which mounts to the camper body, and is slidably telescoped over a jack leg. Extension and retraction of the camper jack leg is accomplished with rotation of a lead screw that is threaded through a plastic nut mounted within the jack leg. Rotation of the lead screw is effected by the operation of a right-angled gear assembly, disposed within the jack housing. The gear assembly is operated with a hand crank, which is detachably mounted to the jack via a socket assembly. In one embodiment, the hand crank is provided with a ratchet and paul mechanism. The socket is implemented so that the coupling between the hand crank and the gear assembly occurs completely within the jack housing. In this way, the socket extends through the wall of the jack housing in a manner so as to be substantially flush with the exterior surface of the jack housing.

Abstract: A breakaway post coupling with a hollow, tubular sleeve which accomodates a ground-mounted stub post and a top, sign-supporting post. The sleeve is held onto the posts by a plurality of pins which engage a corresponding plurality of slots in the sleeve. Collars slidably engage the sleeve and force the pins into the post material as the collars are drawn over the sleeve and pins. A plurality of cutouts in the sleeve define a shear point in the coupling. When the top post is struck by a vehicle, the coupling breaks at the shear point, leaving an intact stub post upon which a new top post can be joined.

Abstract: A frangible guy attachment adapted to be connected between a cable guy and a stationary guy anchor includes first and second elongated coaxial rods. The rods can either be formed as separate elements or can be formed integrally. In both cases the rods are constructed of an elongated rigid structural material. An intermediate coupler is coaxially fixed between the rods. The rigidity of the coupler exceeds that of the rods to concentrate shock bending stresses at an axial transition between one rod and the more rigid coupler. This stress concentration will cause the rod to fracture and break as a result of the sudden impact. A special clevis interconnects the lower end of the lower elongated rod and a conventional guy anchor, preventing subsequent attachment of additional cable guys to the anchor.

Abstract: A breakaway net attachment system for mounting a basketball net to the rim of a basketball goal at predetermined locations along the rim. The system includes clips which are attachable to the rim and which include retainer portions for retaining the net in association with the rim. The rim preferably includes a plurality of studs located along an undersurface thereof for engaging within apertures formed in the clips whereby the clips are retained in engagement with the rim. In one embodiment, the clips are provided with fingers for retaining the net wherein the fingers will release the net in response to a predetermined force being applied to the net. In a further embodiment, the clip is adapted to be pulled off of the rim when a predetermined force is applied to the net.

Abstract: A support arrangement for supporting an object above ground level is designed to reduce hazards for passing motorists. The support arrangement includes an above-ground portion rigidly connected to an in-ground portion by a frangible connector assembly. The above-ground portion can include a generally horizontally extending portion for supporting an object in a cantilevered manner. The horizontally extending portion is formed as part of a moveable portion connected to a generally vertically extending fixed portion by a rotatable connector assembly. The support arrangement is designed to bend and break away in a predetermined manner when impacted and, if it does not break, the rotatable connector is designed to permit the moveable portion to be pulled free and thrown clear of the vehicle. If only the cantilevered object is impacted, the object and moveable portion can rotate out of the path of the impacting force. Once the impacting force has passed, the moveable portion will return to an at-rest position.

Abstract: A restorable breakaway post having a base post and a breakaway post which are connected with a breakable splice plate. The position of the base post is fixed with respect to ground or another suitable structure. A flexible member has opposing ends secured with respect to the base post and the breakaway post. Upon an impact force applied to the breakaway post, the splice plate shears and thus allows the breakaway post to move away from the base post. Under such impact force, the flexible member retains the breakaway post in a relatively close position to the base post. The broken splice plate can be easily replaced to restore the breakaway post to its initial condition.

Abstract: A breakaway base and upper-separation joint for use with highway luminaire supports. The breakaway base, circular in cross section, has a lower-base section with a first rim, an upper-base section with a second rim, a split-ring retainer, and a perimeter band. The split-ring retainer captures the first rim of the lower-base section and the second rim of the upper-base section. The perimeter band encircles the split-ring retainer. In response to a vehicle impact with the upper-base section, the perimeter band fractures, causing disjunction of the split-ring retainer and allowing the upper-base section to separate from the lower-base section. Alternatively, the breakaway base is radial-spoked when viewed from above and has a first plurality of rims on the lower-base section, a second plurality of rims on the upper-base section, a plurality of retainer segments to engage and capture the first and second plurality of rims, and a plurality of fasteners to secure the retainer segments against the rims.

Abstract: A break-way connector for a sign post having a stud rigidly welded to two spaced-apart channel members, with a central portion of the stud between the channel members having a groove and a pair of radial bores centered on the groove to define an area for shearing upon sudden impact, the break-away connector joining together an in-ground post and an above-ground post for holding a sign.

Abstract: A cable retraction system is described which includes a windup reel (16) and power springs (24, 26, 28) that urge the reel to turn and wind up a signal-carrying cable (20). An outer end (25) of each power spring is bent about 180.degree. to form a hook that projects through a slot (72) in a windup drum (36) of the reel. A screw (44) projects through a lug (38) at the end of a cable wire, through a hole (71) in the spring, and into a threaded insert (50) set in the windup drum. A stationary axle (30) at the center of the reel, comprises a dielectric body (71) and a plurality of conductors (73, 75, 77) embedded in the body, each conductor having an outer end (58, 60, 62) at the end of the body to connect to wires of a second cable, and each conductor having an inner end (74, 76, 78) lying at the periphery of the axle and attached to an inner end ( 32) of a spring.

Abstract: A bendable marker for use in areas where the marker is required to be flexible is provided with a base and a marker post which are joined together by a flexible sleeve. The flexible sleeve has a plurality of evenly spaced ribs which extend longitudinally along the sleeve from an upper end to a lower end. The ribs are evenly spaced apart with a groove being formed between each of the ribs. The ribs protrude from both the inner and outer surfaces of the flexible sleeve. If the marker post is struck, the flexible sleeve allows the marker post to bend relative to the base. The ribs strengthen and enhance the resiliency of the sleeve.

Abstract: A display holder (10) is formed from a main frame member that is a single extrusion. The main frame member includes opposite edge frame portions (28, 30) and a center panel (10). Frame portions (64, 66) snap onto the ends of a center panel (10) to complete a frame that extends entirely about the periphery of the display holder (10). The display holder (10) may be mounted by a mounting member (44) which includes a hinge strip (92). Hinge strip (92) and a pair of mounting member flanges (42, 90) may be made by a co-extrusion process. A rigid structural plastic is used to form the flanges (42, 90). A bendable, resilient plastic is used to form the hinge strip (96). The hinge strip (96) will bend in response to a side force applied to the display holder (10). Hinge strip (92) will act as a spring and will swing the display holder (10) back to its at rest position when the force is removed.

Abstract: A support includes a base member having an open end and a hollow interior, a forcing member having an end extending through the open end of the base member into the hollow interior thereof and having threads thereon and a mandrel or sliding nut capable of engaging the threads of the forcing member at an adjustable position and providing an interfering relationship between the base and forcing members as a compressive load is applied thereto. The support is particularly adapted for use in supporting the roof of a mine.

Abstract: Self-locking pipe anchors for anchoring pipes to structural members and particularly for anchoring air lines and other train pipes to structural members in the underframes of railway cars. Each pipe anchor includes a pair of interlocking members for clamping a length of pipe therebetween. One of the members is a base member which is generally saddle-shaped and adapted to be welded or otherwise secured to a structural or frame member to which a pipe is to be anchored. The base member has a pair of ears or flanges extending along opposite sides and juxtaposed to the end of at least one of the ears there is a protuberance having a camming surface opposing the adjacent end of the ear. The other member of the pair is a wedge which is adapted to be driven into self-locking assembly with the base member so as to clamp a longitudinal length of pipe therebetween. The wedge member has channel-like formations extending on opposite sides each of which embraces one of the ears when the members are assembled.

Abstract: A system for indicating the use of a fall arresting device to arrest a fall wherein a collapsible member is mounted on one of the load supporting members so that the collapsible member will collapse when a predetermined load has been applied thereto but will remain substantially in place to indicate that the predetermined load had been applied thereto.

Abstract: A strap is coupled between the sliding upper track of a power seat adjuster and the lead screw of a horizontal drive to transmit forces acting on the upper track which move the upper track in a forward direction to the lead screw bypassing the horizontal drive gears. The horizontal drive gears coupling the horizontal drive motor output shaft to the lead screw and the gear housing surrounding the drive gears are formed of a plastic material. In one embodiment, the strap has first and second ends with the first end loosely surrounding the lead screw. The second end of the strap is coupled in a force transmitting path with the upper track. An intermediate portion of the strap between the first and second ends is formed in a predetermined contour to deform under tension toward a planar shape and is disposed bypassingly around the drive gears.

Abstract: A mine prop has a post or column formed by two telescopingly interfitted tubes, one of which has a bottleneck configuration over which the other is spread to provide a resistance to telescoping contraction. At the upper end, a nut is rotatable on the post and can advance the threaded spindle engaged therein to brace the prop between the roof and ceiling of a subterranean structure.

Abstract: A frame which forms the outer shape of a supporting bracket is constructed so as to be thinner from one portion on the side of a pillar-to-pillar member to another portion on the side of a knee panel. Inside the frame, an inner frame is constructed by ribs and the frame. Deformation of the shape of the ribs allows the supporting bracket to be easily constructed which has impact energy absorbing and deformation characteristics.

Abstract: A pipeline breakaway mechanism is provided which includes an elbow in a pipeline and two clamps holding the pipeline to a structure such as a platform or another pipeline. When a strong pull is exerted on the pipeline, the pipeline is bent until it buckles around the first clamp; the first clamp then fails at a preset load, causing the pipe to bend around the second clamp and causing the previously formed buckle to straighten. This buckling and straightening of pipe causes the pipe wall to fracture at a load much smaller than its tensile strength.

Abstract: A volume control device mounting mechanism for on-vehicle equipment comprising: a variable resistor having a shaft; a knob mounted to an end of the shaft; a chassis for securing the shaft; a insertion hole formed on the chassis, the shaft being inserted through the hole; and slits formed on the chassis around the insertion hole, whereby mechanical strength of the chassis around the shaft insertion hole is slightly decreased from that of other portion of the chassis. The slits provided on the chassis prevent the volume control knob and the shaft from destruction due to large impact force, thereby the variable resistor as well as the knob and the shaft can be reused and human body of cardriver can be protected from injury.

Abstract: A personnel fall-arrest system including a flexible safety track (1) which is anchored in spaced relation to a fixture (2) by track anchors (4), and a coupling component (7) for connecting a worker's safety harness to the track via a safety line (8), the component (7) being freely displaceable along the track. Each of the track anchors (4) is formed so that it becomes permanently deformed if subjected to heavy loading due to a fall, thereby signalling that the system requires to be checked and re-certified before further use.

Abstract: An improved mailbox support (10) includes a sectional post (12) interconnected by a resilient coupling (20).

Abstract: A breakaway connection is mounted between a lower and an upper post section for upstandingly supporting the upper section on the lower section. The breakaway connection has a U-shape cross-section with lateral flanges. A weakened linear section extends horizontally on the flanges and partly on the U-shaped portion and is adapted to break upon a lateral impact. The linear section extending downwardly into folds between the flanges and the U-shaped portion of the connection for allowing the upper part of the connection to tilt backwardly while both the upper and lower parts of the connection remain linked together.

Abstract: A ground-mounted upright mailbox is provided for receiving and storing therein postal material such as letters and variously-sized packages. The mailbox includes a lower mailbox portion which further defines an inner storage compartment, an upper mailbox portion attached to the lower mailbox portion, and a mounting pipe for securing the mailbox into the ground. A laterally deformable lower bellows member is integrally attached to the mailbox subjacent the lower mailbox portion, the lower bellows member allows the mailbox to laterally deflect from its normal upright position when the mailbox is struck by a physical object. Furthermore, the lower bellows member maintains the mailbox in its deflected position until the mailbox is manually righted. In an alternate embodiment, the upright mailbox is secured to the ground by a plurality of mounting pipes. Each mounting pipe includes a flexible, deformable bellows member protruding from one end and which is adapted for attachment to the lower mailbox portion.

Abstract: A roof support for the ceilings of excavated spaces underground and particularly for supporting caving edges for pillar recovery in coal mines is described. The roof support has a roof bar connected to a base frame by hydraulically extendable props and by a lemniscate mechanism. The props are articulated to the base frame and to the roof bar. A link of the lemniscate mechanism has a predetermined bending point. Since this link fails when overloaded before the remainder of the apparatus, it is the only element that need be replaced when the apparatus is overloaded. Thus, the device may be economically repaired.

Abstract: An elasto-plastic damper adapted to be used in a structure for absorbing vibration energy created by earthquake tremors and other ground vibrations. The damper is formed from flat plates to simplify design and to minimize costs. The damper may be used in combination to absorb vibration energy impacting the structure from different directions.

Abstract: The novel collapsible signalling post is provided with a weakened section characterized by an helical groove carved on the periphery of a tubular member to mounted between an anchoring member and a rod member supporting a sign. The groove provides a weakened section adapted to split open along a portion thereof and upon bending caused by a lateral force exerted on the signalling post, the two end portions of the tubular member remain connected to each other by the unfolded spires formed between the helicoidal thread.

Abstract: A recipient for a gas ultracentrifuge which comprises an oblong cylindrical shell having a lid closing each end, a base flange having an upper end surrounding one end of the shell and a plastically deformable ring interposed between the base flange and the shell. In an embodiment of the invention, the plastically deformable ring comprises a ring-shaped section and a welding shoulder which forms a ring-shaped collar integral with the base flange, the thickness of the shell being greater than that of the ring-shaped collar and about the same thickness as that of the welding shoulder.

Abstract: The breakaway assembly includes a cast aluminum base having a collar for supporting a wrought aluminum standard and a base flange for securing the breakaway assembly to a plurality of anchor bolts projecting from a concrete foundation. The base flange includes a plurality of apertures for receiving the anchor bolts. Grooves are provided in the base flange adjacent the anchor bolt apertures. Upon impact, the standard creases and bends causing the heel of the base flange to lift. This lifting motion shears the base flange at the grooves to permit the base to lift away from the anchor bolts.

Abstract: In the case of an apparatus for the fixing of the hydraulic unit of an ABS and/or an ASR in the motor space of a street vehicle, the hydraulic unit is axially supported between one forward and two rearward rubber buffers which are arranged on a console which, in turn, is fixed on the vehicle body. In order to achieve, during an impact of the vehicle on an obstacle, a detaching of the anchoring of the hydraulic unit from the console or the body of the vehicle, at least one holding element of the forward rubber buffer is implemented with a defined low holding force which, starting from a minimum deceleration of the vehicle, results in a deflection of the holding element and thus in a release of the hydraulic unit. This holding element may be constructed to be pivotable or bendable. In a special development, a rivet which, in the case of a crash, acts as a desired breaking point, is provided for the fixing of the console on the vehicle body.

Abstract: An elasto-plastic damper is adapted to be used in a structure, such as a building and other facilities, for absorbing vibration energy created by earthquake tremors and other ground vibrations. The damper is a centrally bulged and generally cone-shaped hollow body of revolution so that its section modulus changes substantially porportional to a bending moment created in the damper body due to horizontal stresses, thus permitting a maximum degree of deformability. This elasto-plastic damper is compact in size and demonstrates a high degree of vibrational energy absorbability.

Abstract: A portable-telephone mounting bracket for installation in vehicles, primarily cars, said bracket having an elongated configuration and including one or more bends and made of a sheet-like material, preferably a plastics material, and which bracket includes a flat part (5) from which an upper arm (6) and a lower arm (7) extend, the outer ends (8, 9) of respective arms being intended to be fitted into a slot in the vehicle instrument panel or in the air intake located on the instrument panel, or at some other location, such that the mounting bracket can be secured to the instrument panel by means of the aforesaid ends, and the flat part of the mounting bracket being intended to support the receiver-cradle of the portable telephone.

Abstract: A steering column fastening for a motor vehicle includes a deformation element between a steering bracket retained at the body and a protective tubular steering member; the deformation element consists of an energy-absorbing plate connected with a bow-shaped bracket member of the protective tubular steering member which plate includes deformation sections which are arranged corresponding with longitudinal slots of the bow-shaped bracket member and in which are guided the displacement bolts extending through the deformation sections. The energy-absorbing plates are arranged between a lower support element of the bow-shaped bracket member and upper guide elements arranged parallel thereto. The upper guide elements are supported at the steering bracket of the body and include longitudinal slots which are arranged corresponding to further longitudinal slots of the lower support element.

Abstract: A mounting arrangement for a vehicle air bag comprises a mounting bracket affixed to a component of the vehicle, a base plate having a mounting portion on which an air bag and an inflator are mounted, and a plurality of fasteners connecting the base plate to the bracket. Plastically deformable structures associated with the fasteners and the base plate are arranged such that the mounting portion of the base plate is displaceable in a direction away from the mounting bracket in response to the forces imposed on the base plate at the end of the development of the air bag.

Abstract: A breakaway hanger comprising a multi-slotted rod, and a separate strap of hook and loop material in adjacent slots i.e. in pairs, said straps dangling from the slotted rod and interengaged to form loops that break away when an excess weight is applied.

Abstract: A fishing rod holder for insertion into an existing beverage holder opening in a boat for the purpose of receiving and supporting the handle end of a fishing rod. The fishing rod holder includes a tubular body member having a flange at its upper end and a tubular receiver secured within the body member. The handle end of the fishing rod can be inserted into and retained within the tubular receiver.

Abstract: A contractible mine stopping adapted to be installed to extend as a vertical wall from the floor to the roof of a passageway in a mine, comprising a series of rows of substantially solid substantially non-compressible blocks of substantially fire-resistant material stacked one on top of another, and at least one row of contractible substantially fire-resistant block-like members adapted to contract without loss of structural integrity when the wall is subjected to a compressive load, as during a convergence of the floor and roof of the passageway. Each block-like member is preferably a hollow metal member which, when subjected to a compressive load, is adapted to contract heightwise of the member a distance corresponding to at least a major portion of the height of the member without loss of structural integrity of the member.

Abstract: An elasto-plastic damper is adapted to be used in a structure, such as a building and other facilities, for absorbing vibration energy created by earthquake tremors and other ground vibrations. The damper is a centrally bulged and generally cone-shaped hollow body of revolution so that its section modulus changes substantially proportional to a bending moment created in the damper body due to horizontal stresses, thus permitting a maximum degree of deformability. This elasto-plastic damper is compact in size and demonstrates a high degree of vibrational energy absorbability.

Abstract: A marker supported in the ground allows a reel-type grass mower to cut grass around the marker without requiring the removal of the marker. The marker has a flexible elastomeric element coupled between a substantially rigid shaft and a substantially rigid stake and for urging the shaft into axial alignment with the stake and for allowing a reel-type grass mower to bend the rigid shaft over at the elastomeric element to a position with a sign member substantially flat with the ground.

Abstract: An attachment structure of a steering column comprises a bracket fixed to a steering jacket for receiving a steering shaft and attaching the steering jacket to a chassis, the bracket being attached to the chassis through metallic contact faces; and a capsule disposed in an attaching portion of the bracket attached to the chassis and having metallic and resin sliders which overlap each other through the bracket and attaches the bracket to the chassis such that the bracket is detachable from the metallic and resin sliders through metallic and resin contact faces.

Abstract: A hose clamp for clamping a swivel hose in a fuel dispensing installation. The hose clamp includes a breakable portion by which the hose clamp is connected to a retrieving cable. When sufficient force is placed on the cable, the hose clamp will break away from the cable thereby releasing the hose from the dispensing installation.

Abstract: A post and ground support is illustrated utilizing a helical member forming an auger for digging the ground support into the earth, and easily removing the ground support from the ground and reusing said support in another location. The ground support includes a ground engaging stabilizing member affording resistance to a force having a component at right angles to the post, and a breakaway connection is provided between the ground support member and the post, together with a connection for retaining the post in a position near the ground after separation therefrom. The breakaway connection positions the post upon the ground support above the ground and separates in response to a force coming from any direction about the post. A shear pin having longitudinally flat surfaces extending circumferentially thereabout prevents turning of the post with respect to the ground support and a groove extending about said flat surfaces assure uniformity of shearing from any direction in which the force is applied.

Abstract: A mailbox post mounting apparatus includes a post bracket and a mailbox bracket affixed respectively to the ground support post and the mailbox respectively. The brackets include abutting plate-like members having aligned openings with the mailbox in the mail receiving position. A break away pin is secured within the openings to lock the mailbox in place for receiving the mail. If the mailbox is struck by a vehicle, the pin releases or breaks away and releases the mailbox and its support from the post bracket and the post. In one unit, a post-bracket has a post securement plate with an integral lock plate extending outwardly and vertically, preferably upwardly. The mailbox bracket has a post securement plate having integral lock plate extending vertically at the same releasable angular orientation as the post plate. A releasable pin passes through aligned openings to lock the brackets to each other.

Abstract: A post and ground support is illustrated utilizing a helical member forming an auger for digging the ground support into the earth, and easily removing the ground support from the ground and re-using said support in another location. The ground support includes a ground engaging stabilizing member affording resistance to a force having a component at right angles to the post, and a breakaway connection is provided between the ground support member and the post, together with a connection for retaining the post in a position near the ground support after separation therefrom. The breakaway connection positions the post upon the ground support above the ground and separates in response to a force coming from any direction about the post.

Abstract: A one-piece wire retainer clip comprises a first tube axially slidable onto and frictionally engageable with a threaded stud on a structure. A pair of resiliently movable spaced-apart legs are connectd to the first tube and define a wire-receiving slot having an opening on one side through which wires are laterally insertable into the slot. A second tube is axially aligned with and slidable manually onto the first tube. A slot closure plate is connected to and movable with the second tube. Releasably interengageable latches are provided on the legs and on the slot closure plate. A frangible web connected between the tubes initially maintains the second tube in an open position wherein the closure plate is spaced from the slot opening. The web remains intact as manual force is axially exerted on the second tube to force the first tube onto the stud.

Abstract: A shock absorbing assembly having sections for controlling the modal deformation of collapse and capable of absorbing the dynamic energy of impact caused by the rapid deceleration of heavy masses is provided. The shock absorbing assembly has a plurality of arcuate steel sections sandwiched between steel plates with an elastomeric rubber compound secured to and covering at least one surface of one plate. Each of the arcuate steel sections are provided with a groove in its soffit.

Abstract: Disclosed herein is an anchorage for a webbing of a vehicle seat belt system. The anchorage is of the type that when an abrupt tensile force is applied to the webbing, a bracket fixed on a seat slide rail is deformed to bring a pin of a base plate secured on the bracket into engagement with a recess of an anchor stay fixed on a stationary base of a vehicle thereby to distribute the abrupt tensile force to the stationary base. The bracket comprises two parts consisting of a first bracket fixed on the seat slide rail and a second bracket which is secured on the base plate and is deformed upon application of a force of at least a predetermined value to the webbing. An engaged portion is provided with one of the first bracket and second bracket while an engaging portion is provided with the other bracket. The engaged portion and engaging portion are normally maintained in mutual engagement.

Abstract: A contractible mine stopping adapted to be installed to extend as a vertical wall from the floor to the roof of a passageway in a mine, comprising a series of rows of substantially solid substantially non-compressible blocks of substantially fire-resistant material stacked one on top of another, and at least one row of contractible substantially fire-resistant block-like members adapted to contract without loss of structural integrity when the wall is subjected to a compressive load, as during a convergence of the floor and roof on the passageway. Each block-like member is preferably a hollow metal member which, when subjected to a compressive load, is adapted to contract heightwise of the member a distance corresponding to at least a major portion of the height of the member without loss of structural integrity of the member.