Abstract: A pad is arranged on the upper and lower sides of a spring unit to provide a laminate structure. The laminate structure is covered with an outer cover body comprising top and bottom layers covering the corresponding pads and a side layer covering the laminate structure. A joining member of heat-shrinkable synthetic resin has one end width portion joined to the inner surfaces of the whole marginal edge portions of the top and bottom layers. The other end width portion of the joining member covers the corresponding outer marginal edge portions of the pads. The joining member, upon being heat shrunk, have another end width portion brought into firm engagement with the spring unit so that the pads and outer cover body are firmly held relative to the spring unit.

Abstract: A bed system with an excreting mechanism of the present invention includes a front base for receiving the upper half of a patient's body and having a first front portion capable of being tilted up or down, a rear base for receiving the lower half of the patient's body and having a second front portion capable of being tilted up or down, a pot seat for supporting the patient's buttocks, a chamber pot for receiving the patient's excretions, and a posture regulating mechanism for regulating the patient's posture. In tilting up of the second front portion of the rear base, the pot seat is positioned between the rear end of the front base and the front end of the rear base, and the chamber pot is positioned under the pot seat. The second portion of the rear base is tilted up or down around the rear edge of the second front portion as a supporting shaft and can be tilted up or down around the front edge of the second front portion as a supporting shaft.

Abstract: A patient-supporting bed especially adapted for cardiac sonography includes a horizontal uppermost bed surface, an exercise apparatus coupled to one end of the bed, a tilting mechanism for tilting the bed surface, and a novel support structure for supporting the patient on the tilted bed. The support structure includes a flexible patient support sling adapted to circumferentially surround the patient's midsection and an adjustable shoulder support apparatus adapted to engage one side of the patient's body while the bed is tilted. The bed surface includes an access opening and a corresponding shiftable bed filler sections disposed within the opening. The bed filler section is shiftable between upper and lower positions and include a latching assembly serving to normally maintain the filler section in an upper, generally horizontal position so that the bed presents a generally horizontal and uninterrupted patient-supporting top surface.

Abstract: A multi-positional bed comprises at one end thereof a pair of pillars. One of the pillars is disposed at or near each side of the bed and at the opposite end a single pillar is disposed substantially on the longitudinal center line of the bed. The bed has a user-supporting frame, and respective mounting devices for mounting the frame to each of the pillars. Each mounting device is arranged to move lengthwise with respect to the respective pillar independently of the movement of the other mounting devices.

Abstract: A modular cushion comprising a shaped base which has a flat rear portion and a raised front portion with angularly directed valleys and a raised pommel to direct weight to the thighs and in combination with a resilient pad positioned on the flat portion of the base to relieve pressure on the ischial and trochanters and in combination with a cover having a non-skid undersurface and a portion of the top being two-way stretchable. The resilient pad may be of inflatable cells having a pyramidal shape with a flattened top. A U-shaped restraining member may be positioned at the front of the base with upwardly projecting sides to retain the legs of the user.

Abstract: An apparatus and method for applying textile treatment finishing agents to garments or garment work pieces is provided. The apparatus includes a rotating drum and a nozzle for generating a fine mist or fog of textile treatment agents inside the rotating drum. The apparatus can be constructed as a dedicated processing machine, or a conventional, industrial washer or dryer can be fitted with an appropriate nozzle and feed lines to provide a dual purpose machine which can be used for its originally intended purpose, and can be selectively used for applying textile treatment agents. Uniform coverage of the surface of the garment is assured by tumbling the garments through the fog created by the nozzle means. By controlling the size of the droplets, and the time during which mist or fog is generated, the amount of chemical agent absorbed by the garments can be controlled.

Abstract: To mount a multiple strand stay of a stayed bridge between a tower and a deck of said bridge, one of the strands (4.sub.1) that is to make up the stay is installed in its final oblique position; a guide cage is suspended from said strand installed in this way, the cage being constituted by a sequence of rigid hoops (5) that are interconnected by strings (6), said cage surrounding said first strand and also surrounding a traction cable (9); said cable is used to pull successive strands (4) up inside the cage; after each strand has been pulled up, it is put under tension so that it bears laterally against the already installed strands, and its ends are anchored respectively to the tower and to the deck; and after all of the strands have been installed, the guide cage is removed from the completed stay.

Abstract: A dental device for an electric toothbrush drive having a drive shaft, the dental device including a housing, a motion converter arranged in the housing and including a rocker arm, a rotary oscillation plate having an eccentrically arranged plug-in opening, and a plug-in axle for operatively connecting the rotary oscillation plate to the rocker arm via the plug-in opening. A guide is provided for releasably and operatively connecting one end of the rocker arm to the drive shaft of the toothbrush drive, and a bearing is provided for rotatably supporting the rotary oscillating plate at the housing. The motion converter converts the movement of the drive shaft into rotational ocillatory movement of the rotary oscillation plate about the plug-in axle.

Abstract: A motor vehicle washing apparatus having a brush assembly and curtain assembly for prolonging the life of the brush assembly and the curtain assembly by adjusting the length of elements of each when wear occurs. The brush assembly includes a plurality of brush elements mounted on a rotatable drum by connectors which are removably received in channels on the outer surface of the drum. The connectors engage selected slots of a plurality of slots in the brush elements to allow for selectively and incrementally adjusting the position of a free end of each brush element. In a similar fashion, the curtain assembly has a plurality of curtain elements mounted on a support rod or on an oscillating semicircular drum. The curtain elements each have a plurality of slots therein for accommodating self-orienting removable locking fasteners permitting selective and incremental adjusting of the position of a free end of each curtain element.

Abstract: A magnetic disc for a cleaning device which is passed through a pipeline having a cylindrical internal wall. The magnetic disc includes a flexible circular disc body perpendicular to the cylindrical wall, the disc body having a plurality of radially spaced openings therethrough. A magnet is installed in each opening in the disc body, each magnet having poles oriented axially with the cylindrical wall. A pair of opposed retainer plates for each magnet are fastened to the disc body to retain the magnet in the disc body and to extend the magnetic field of action.

Abstract: A hand-held device for cleaning data-bearing cards includes a housing, a fluid applicator pad, a scrubber pad, a drying pad, and a removable panel. The housing includes a first surface to oppose the portion of the card to be cleaned. A first recess is disposed within the first surface. The first recess has an aperture extending through the housing. A second recess is also disposed adjacent the first recess within the first surface. A third recess is disposed adjacent the second recess within the first surface of the housing. The first, second, and third recesses are generally linearly aligned. The fluid applicator pad is disposed within the first recess. The scrubber pad is disposed within the second recess. The drying pad is disposed within the third recess. Each of the pads is thicker than the depth of its corresponding recess such that the pads project partially above the first surface of the housing. The panel is removably coupled to the housing.

Abstract: A mat in which an element of thermoplastic resin as the base material for anchoring a name is integrated with a mat main body so as to be exposed on the surface of the mat main body. A name seal is welded on the surface of the element of thermoplastic resin. The name seal is made out of thermoplastic resin and may have coloring and design which does not impede the name display.

Abstract: A floor mop for cleaning a floor. The floor mop includes a mop head and a handle pivotally connected to the mop head. A disposable cleaning sheet is attached by a minor portion adjacent one edge to a leading edge of the mop head, leaving a major portion of the cleaning sheet free. The mop may be passed over the floor with one side of the cleaning sheet presented for cleaning the floor. The mop head may then be inverted with the other side of the cleaning sheet presented for further cleaning of the floor.

Abstract: A backing plate for a rotary buffing pad assembly provides cushioned support for a pair of curved edge buffing pads mounted back-to-back. The backing plate is adapted for easy reversible mounting and the cushioned pad support prevents damaging contact by the edge of the rigid backing plate with the surface being finished.

Abstract: Cedar chips are used as an air freshener and pesticide in a vacuum cleaner bag. The chips can be loose or contained in a porous "tea bag." Cedar oil may be used to augment the effect of the chips. The chips are placed in the receptacle or vacuumed from the floor.

Abstract: A ladder-upright-mountable, paint tray assembly is provided wherein at least one bracket assembly is provided on the underside of upper, paint draining portion of the paint tray assembly. Therefor each bracket assembly is a sliding fit on the ladder upright and hooks over a portion of a ladder rung adjacent that upright. A central bracket assembly may be provided alone or in combination with two side bracket assemblies. In other embodiments only two side brackets are provided. Pairs of paint container wall members may also be provided, aligned with the bracket assemblies, for the ladder upright to be slidably retained therein.

Abstract: A seal for a swivel caster assembly is disclosed. The seal protects the first ball bearing set of the assembly. The seal has a V-shaped cross section formed by seal legs that are joined at a bight and extend radially inward, and are in surface contact with the top plate and a notched swivel element of the assembly. The seal includes embossments that engage the notched swivel element and accept the pin of a swivel lock assembly.

Abstract: A door closer being affixable to a door for closing the door. A channel having a slide therein for engaging with a detent also in the channel for holding the door open. The slide is connected to an arm of the door closer which arm moves the slide along the channel into contact with the detent which holds the door open once the detent and the slide have engaged with one another.

Abstract: Disclosed is a light weight handle assembly adapted to transport a heavy duty container which may contain sensitive electronic components. The handle assembly of the present invention generally comprises a stationary bracket which mounts to a container wall and a movable handle pivotally connected to the bracket. The bracket is formed with an inner portion that is adapted to rotatably engage with a pair of pivoting arms extending from the movable handle so that the light weight handle may easily be assembled and disassembled. The stationary bracket is also formed with two stationary stop members while each of the pivoting arms are formed with a corresponding movable stop member.

Abstract: The arrangement includes a release control mechanism and an inner tube positioning structure, wherein the release control mechanism consists of a hollow control block fixed between the sleeves of the retractable luggage handle, a sliding block slidably mounted on two downward rods inside the control block, two curved springs respectively fastened to the downward rods and stopped against the sliding block at the bottom, and a press bar fastened to the sliding block and disposed outside the control block and pressed to force down the sliding block causing the two opposite sloping ends of the sliding block to push back the spring bolts on the inner tubes permitting the inner tubes to be collapsed; the inner tube positioning structure of female locating elements and male locating elements respectively fastened to the sleeves and the inner tubes for allowing the inner tubes, the female and male locating elements being respectively connected together when the inner tubes are received inside the sleeves.

Abstract: A drafting frame includes a drafting unit for drafting a plurality of slivers running in an advancing direction and combining the slivers into a single sliver; and a sliver guide situated upstream of the drafting unit. The sliver guide has converging walls defining a cavity for guiding therein the plurality of slivers which are gathered by the cavity in a side-by-side orientation in a single plane. A sensor element is supported for displacement relative to the sliver guide. The sensor element has a sliver-contacting face movable toward and away from a counterface forming part of the cavity wall and defining therewith a constriction of the sliver guide. A force urges the sliver-contacting face of the sensor element towards the counterface to compress the slivers running through the constriction. A transducer is coupled to the sensor element for emitting a signal representing excursions of the sensor element in response to thickness fluctuations of the slivers running through the constriction.

Abstract: A short cycle unevenness control device in the delivery part of a carding machine. The device includes a set of measuring rollers 26 and 37 for receiving a sliver from a funnel and a set of drafting rollers 23 and 42 for issuing the sliver S to a coiler. The top measuring roller 37 is provided with an annular groove 36, while a bottom roller 26 is provided with an annular flange 25, which engages with the annular groove 36. The top drafting roller 42 is provided with an annular flange 41, while a bottom drafting roller 23 is provided with an annular groove 22, to which the flange 41 engages. Furthermore, the flange 41 of the top drafting roller 42 engages the groove 36 of the top measuring roller, while the flange 25 of the bottom measuring roller 46 engages the groove 22 of the bottom drafting roller 23.

Abstract: An information carrier for clamping onto rods (S), particularly clothes rods or the like, having a holding clamp which, by its two first arms of a resilient material, forms a substantially C-shaped clamping jaw to receive the rod (S), having at least one second arm which extends into the clamping jaw and which, together with a partial region of its side surface, forms a holding region for resilient action on the rod (S). In order to achieve a greater field of use, the second arm (3) be formed resilient on the free end (2') of the first arm (2).

Abstract: A sleeve stretcher assembly for the ends of an elastomer sleeve of a spreader roller which includes a stationary shaft having at least one of its end portions configured as a tube. A slide rod is adapted for sliding interior of said tube in a direction parallel to an axis of the shaft. A hub member is arrayed exterior of said tube while being connected to the slide rod by a pivot means. An axis of the hub member is selectively tilted with respect to an axis of said shaft by a tilt adjusting means. The slide rod is selectively positioned interior of the tube by a linear adjusting means. The selected linear adjustment is maintained by a locking means.

Abstract: A sheet-metal strip provided with mutually staggered cuts is conveyed continuously at a first speed through a first conveying apparatus (23) and at a second speed, increased as related to the first speed, through a second conveying apparatus (24). Thereby, the strip section (21) freely traveling between the first and second conveying apparatus (23, 24) is stretched with the formation of a three-dimensional expanded grid structure. The process permits a continuous, rapid production of expanded grids of high precision and uniformity, especially with regard to mesh width and grid height.

Abstract: A tire rasp blade for use in a tire buffing machine having a rotating hub. A set of rasp blades is arranged in a plurality of circumferential rows. Each of the blades has a non-planar elongated body with generally planar portions, and an arcuate working edge having teeth which extend in a direction generally parallel to the direction of hub rotation. The working edge includes two elliptical-shaped segments.

Abstract: A curtain apparatus having a hood with a top plate in which a plurality of slots are positioned approximately parallel to each other. A fixed woven mesh metal curtain is mounted within one slot so that the fixed woven mesh metal curtain remains in a fixed position with respect to the top plate, during operation of a descaler. A moveable woven mesh metal curtain is mounted within another slot so that during operation of the descaler, the moveable woven mesh metal curtain can translate along a longitudinal axis of the slot. The moveable woven mesh metal curtain is detachably engaged with a curtain bracket that is secured to a moveable guide arm.

Abstract: A seat skinning mechanism for skinning a flexible membrane cover on a polymeric foam vehicle seat body is provided which, in a preferred embodiment, includes a first support surface for positioning the seat body located generally underneath the seat body, a second support surface contacting the seat body on a first vertical side of a seat body, first and second powered wings pivotally mounted with respect to the second support surface, the wings causing the lateral edges of the seat body to fold upon themselves to an extent to allow the flexible membrane cover to be placed over the foam body, the second support surface and the wings, and a lift to force the foam body upward, removing the seat body from between the second support surface and the wings with the membrane cover on the seat body.

Abstract: The present invention relates to a method of producing pivoted tools such as scissors, pliers, pruners, and the like. More particularly, this invention is concerned with the method of producing tools having a force applying end with formed handles, and opposed working ends disposed across a pivotable joint. In these tools, the pivotable joint comprises a pivot member formed concurrently with the handles as an integral part of one of the handles.

Abstract: A method for minimizing thermal overhead in an integrated circuit package is described. A heat sink having a base is integrally formed into the package. The base is connected to the die, and a portion of the heat sink projects from the package, forming a post. A heat transfer assembly having a shaft with an aperture is heated until the aperture expands sufficiently to allow the heat transfer assembly to be fitted on the post with a minimum of force. Upon cooling, a tight joint is formed between the heat sink and the heat transfer assembly.

Abstract: In manufacturing a metal bellows of high rigidity by using relatively simple equipment, a plurality of annular concavities are formed around the outer periphery of an unprocessed tube to form an intermediate product. Then, a core iron is inserted into the intermediate product while the annular concavities around the outer periphery are braced. Subsequently, the intermediate product is pressed in its axial direction to be formed into the metal bellows.

Abstract: An electrical caulking method for a work made from a magnesium or a magnesium alloy wherein a caulking pin integrally projects from a body, wherein an electric caulking apparatus having two opposing electrodes is used. The work is held between the opposing electrodes so that one electrode contacts the caulking pin and the other electrode contacts the body while an electric current is applied between the electrodes and pressure is exerted therebetween, thereby caulking the caulking pin into a desired shape, and providing at least the one electrode that is brought into contact with the caulking pin of the work of a material having low thermal diffusivity and which is difficult to alloy with magnesium.

Abstract: A method of manufacturing electrically conductive elements such as electrodes for EDM, ECM or other electromachining processes comprises the steps of designing a digital representation of the element, making a three-dimensional replica of the element from an intermediate material, e.g. a polymer, based on the digital representation, and coating the replica with a layer of a good electrical conductor. The replica is made using a tool-less prototyping process. The method is faster and less expensive than conventional machining of copper or graphite EDM or ECM electrodes, especially those having an intricate shape.

Abstract: In a continuous process for continuous casting and hot-rolling of metal sheet, off-line storage of a slab takes place in a thermally insulated storage chamber located alongside a thermally insulated zone through which the slab lengths travel in the production line between a cutter for the slab and the hot-rolling mill train. On stoppage of the hot-rolling mill train, at least one slab length is transferred laterally to the off-line thermally insulated storage chamber. To improve ductility, an induction heating stage is combined with a subsequent temperature-maintaining stage in the furnace for homogenization of temperature within the slab. Both these stages are performed on the slab at its casting thickness.

Abstract: A pedestal is fixed inside an outer casing of the flowmeter and a core is fixed on the pedestal.In one embodiment, the outer casing to which the core is fixed is rotated by a power roller, and slits are cut into the core by a laser beam apparatus. The cutting of such slits reduces the eddy current in such flowmeters. Depending on the movement of the laser apparatus with respect to the rotation of the outer casing, a spiral slit or a circular slit may be formed. Other patterns of slits may also be cut. A lathe may be used in place of the laser apparatus.The flowmeter includes an exciting coil, a measuring pipe and other necessary elements which are fixed to the outer casing after the slits are cut in the core.

Abstract: A dry type transformer has an iron core, high voltage windings embedded in cast resin, and low voltage windings resin encapsulated. The low voltage winding is constructed with flexible sheet conductors coincident with layer insulation sheets that extend beyond the edge of the sheet conductor. Cooling air ducts are fabricated in the low voltage windings as it is wound. To prevent the extension of the layer insulation sheets from collapsing over the formed air ducts during a vacuum and pressure resin impregnation process, reinforcing means are added to the extensions to prevent them from collapsing.

Abstract: A coil is provided for use in a deflecting electromagnet in which two coil end portions are bent as well as a method of manufacturing the same. In the coil, a plurality of coil units in each of which two coil end portions 3c are bent such that they oppose each other are laid on top of one another, and the individual coil units are electrically connected to each other. Alternatively, two-layer coil units in each of which the two ends of the conducting wire are located on the outer side of the outer diameter portion of the coil unit are laid on top of one another, so that all the connecting portions of the conducting wires between the individual two-layer coil units can be located on the outer side of the outer diameter portions. Alternatively, the connecting portions of the conducting wires between the individual coil units are extending such that they are separated from the coil unit.

Abstract: An electronic module assembly (10) is constructed by attaching semiconductor die (20, 22) to corresponding ceramic substrates (16, 18). A solder preform (14) is placed between the ceramic substrates and a base plate (12) which in turn is placed on a mounting fixture (26). Steel shims (28-42) are placed around the perimeter between the base plate and the mounting fixture surface. A restraining mechanism (24) passes through the center of the base plate and fastens to the mounting fixture to create a force on the base plate causing it to bow in an elastic manner. The assembly is reflow soldered and cooled with the module assembly restrained in the pre-bow apparatus. The elastic bow compensates for differences in thermal expansion and contraction characteristics between the ceramic substrates and base plate encountered during the reflow and later processes to prevent stresses from developing on the solder bond between materials.

Abstract: A flexible printed circuit board is constituted with a first insulation film covering a first insulating resist layer, a second insulation film covering a second insulating resist layer and a printed circuit formed between the first insulating resist layer and the second insulating resist layer, and a terminal of an electronic component is disposed on the printed circuit, and the second insulation film is pressed and heated.

Abstract: A method for the manufacture of piston rings, includes the steps of producing a tube and machining the desired ring free shapes on the inner and outer diameters of the tube providing desired cross sectional profiles by grinding, for example, and then cutting the individual rings from the tube. The ring gaps are preferably formed after cutting the ring from the tube. Coatings on the ring outer surface may be applied and shaped while in tube form.

Abstract: The invention is directed to a method for easy and reliable manufacture of a silencer constructed with a multi-perforated inner tube and an outer tube, between which a sound-absorbing material such as glass wool, etc. is filled in, without use of a binding agent, etc. The invention is also directed to provide an apparatus for use in the manufacture of such silencer.

Abstract: A gate valve comprising a valve body, a gate, a bonnet assembly and an actuator assembly. The gate having a closure area, a flow opening extending through the gate, and a recess circumscribing the flow opening and the closure area having a material disposed therein and case hardened to form a wear resistant sealing surface about the flow opening and the closure area having a hardness greater than about 50 Rockwell. The gate being press fitted between a pair of seat rings such that the sealing surface remains in sealing engagement against the seat rings to provide a substantially fluid tight seal when the gate is in an open and closed position. The actuating assembly is connected to the gate for reciprocally moving the gate across the flow bore between the open position and the closed position.

Abstract: A composite vehicular wheel assembly (10) has a permanent ornamental surface treatment. The wheel assembly (10) includes an annular rim (12) having two rim flanges (14). A spider (20) is fixed within the rim (12) and attaches to a rotating hub (22). The spider (20) includes a plurality of radial spokes (24). Lug stud holes (32) are formed in the spider (20) and are circumferentially spaced about a central axis of the assembly (10). A stamped sheet metal applique (34) conforming to the outer surface curvature of the rim (12) and spider (20) is adhesively attached with an epoxy (42). The applique (34) is chrome-plated to simulate a conventional prior art electroplate chrome wheel assembly. The applique (34) includes vent openings (40) positioned between the spokes (24) of the spider (20), and apertures (52) aligned over each of the lug stud holes (32) of the spider (20) for passage of the lug studs (31). A separately detachable center cap (29) attaches to the spider (20) and/or the hub (22).

Abstract: A simple, purely mechanical, hand-held yet handleless, do-it-yourself hair trimming device employing conventional razor blades and operable by a typical combing motion. The blades are sandwiched between a base element and a mating backing element, both of which have one or more arrays of comb-like teeth and the backing element may be a comb per se. The base and back elements are disengagably adjustably secured together by a spring-loaded thumb screw/cup nut configuration which allows ease of blade replacement and versatility through user selection from multiple tooth array/blade edge combinations, intended to maximize the efficiency of the cut with regard to the various different areas of the head.

Abstract: A razor head comprising at least one movable skin-engaging element which moves in response to forces encountered during shaving and a cleaning member for selectively dislodging shaving debris from small spaces on the razor head. A pair of resilient, spring fingers are integrally formed with the cleaning member for biasing the skin-engaging element. The cleaning member is provided with an actuator button to allow a person shaving to move the cleaning member forwardly to dislodge shaving debris.

Abstract: A shaving kit comprises an openable, box-like body having a main portion and a lid, a blade assembly and a releasable connection for the blade assembly to said body. The body defines when closed, an inner space for housing shaving aids, in particular shaving gel or cream and optionally after-shave gel or cream, in suitably packaged form. The body has portions that match and interlock with portions of the blade assembly and is provided with a seat-shaped upper surface to support the blade assembly during the shaving operation. A hygienic cover is slidable over the blade assembly to protect the same when not in use.

Abstract: A new style trim knife comprising a handle, a head on a first end of said handle and a blade. Components are for securing the blade to the head. A hand of a person can grasp the handle to allow the blade to cut off protrusions and rises left by a molding process on plastic, rubber and any other molded product at a work area. A facility is built into the head for removing by a suction action the loose cutoff protrusions and rises with a vacuum unit. The loose cutoff protrusions and rises will not cause damage to equipment located at the work area.

Abstract: Circular-bladed pruning apparatus with holding action includes a mechanism for securing a severed branch of a plant from the moment the branch is cut until a user chooses to release the branch. A rotatable, indexed, circular blade is included, as well as a handle for operating both the cutting mechanism and the holding mechanism. The present invention may also include shields designed to protect a user's hand and arm from injury resulting from harmful plant contact.

Abstract: A knife has a handle adapted for gripping by a user's hand and an elongated blade mounted to the handle and extending generally longitudinally outwardly therefrom. The blade defines a longitudinal sharpenable cutting edge for cutting through a variety of materials. The handle has a plurality of pairs of bilateral sharpening guide indentations formed on opposite side portions of a forward end of the handle adjacent to opposite sides of the cutting edge of the knife blade. The pairs of guide indentations are formed at respective different angular relationships to the cutting edge of the blade for facilitating the alignment of an elongated sharpening bar at appropriate angles to the cutting edge to correctly sharpen the knife blade.

Abstract: A lock blade knife having a handle portion and a blade, the handle portion having a pair of spaced side plates which enclose the blade between them together with a spring which is urged towards the blade. One end of the spring is provided with a pawl which is received in a notch at one end of the knife blade when the blade is in the open position. When the pawl of the spring engages the notch of the blade, the latter is locked in open position. One plate is provided with a T-shaped slot consisting of a vertical oval slot and a transverse intersecting slot. A lever consisting of a button attached to a piece of spring steel which is bent at right angles is received in the T-shaped slot. The spring steel includes a vertical portion which connects at right angles to a horizontal portion, the horizontal portion having a pair of horizontally extending arms which bear against the edge of the horizontal slot.