Abstract: A low profile latch mechanism for an access panel that minimizes external structural discontinuities while concomitantly providing external access to engage and/or disengage the latch mechanism for closing and/or opening of the access panel. The latch mechanism includes an insert member mounted in rotatable combination with the internal surface of the access panel, a captured floating nut mounted in nonrotatable combination with the internal surface of a frame segment, a safety lock member mounted for axial displacement within the captured floating nut, and a removable key member. The removable key member is insertable through an access aperture in the access panel to engage the insert member for rotation thereof to threadingly engage the captured floating nut to close the access panel. The safety lock member is biased to engage the insert member to lock the low profile latch mechanism in the fully engaged state upon removal of the key member.

Abstract: An enclosure and latching structure for the cable compartment of a tank for a padmounted distribution transformer. The enclosure is of non-conductive fire resistant material. A curved latch arm of non-conductive material is pivotally connected to support structure mounted on the front tank panel of the transformer above the midpoint thereof. The enclosure is shaped to conceal the cable compartment of the tank and is open at the back for engaging the periphery of the tank panel. The enclosure has an opening in the front adjacent the top thereof through which extends a locking device secured to the enclosure for mating with locking structure carried at the free end of the latch arm.

Abstract: An improved locking bolt for a T-handle assembly is provided. The locking bolt has an associated security collar which encircles the bolt and prevents axial movement of the T-handle housing relative to the bolt when the threaded end of the bolt is threaded into the door frame of the closure. The security collar is held in place by a pin which extends through corresponding apertures in the collar and the bolt. A ball bearing is positioned in a recess formed in the bolt to prevent axial movement of the collar on the bolt in the event that the pin is defeated. The bolt and the security collar also act as a secondary locking mechanism by preventing rotation of the bolt when the lock is released, a special wrench being required to rotate the bolt after the lock is removed.

Abstract: Assembly of a radiator into the engine compartment of an automotive vehicle is quickly accomplished by raising the radiator with its lower support until projecting pins on the top of the radiator extend through a pair of openings in the upper cross member. A fastener and isolator unit is initially installed on each of the pins so that a lower retainer of the hard plastics main body of each unit inserted through the respective slot is immediately below the lower surface of the cross member while an upper retainer is located above the upper surface of the cross member. Installation is effected by gripping ears on the upper retainer and turning the unit on the pin until camming and positioning surfaces of a neck connecting the upper and lower retainers engage the edges defining the slot while trapping the cross member between the upper and lower retainers to secure the unit thereto.

Abstract: A power gas tank cover including a motor, a collar including an annular portion, a tubular portion formed at one side of the annular portion and having a hole communicated with an opening of the annular portion, a recess between the annular portion and the neck portion, and an inclined track on an inner side of the neck portion, a worm shaft inserted into the tubular portion and connected with the motor, a sleeve fitted in the inclined track, an inner jacket being a cone-shaped member with a first orifice, an outer jacket rotatably fitted on the inner jacket and provided at a lower portion with a worm gear meshed with the worm shaft, a pressure relief valve arranged on a top of said inner jacket, and a transmission shaft pivotally connected with the outer jacket at an end and with a gas tank door at another.

Abstract: A locking mechanism for securing sliding glass panel units including an elongate threaded fastener having a threaded forward end section and a rear end section. This fastener has a knob or handle for rotating the fastener about its central axis, this knob being mounted on the rear end section. A mounting plate is used to rotatably mount the fastener in a support frame so that the fastener extends through a hole in the plate and the support frame. An anchor with a threaded aperture is fixedly mounted in the sliding glass panel unit and this aperture is capable of threadedly receiving the forward end section of the fastener. Preferably a spring is arranged on the fastener between the mounting plate and the knob or handle, this spring acting to bias the fastener away from the anchor. The mechanism can be used with either sliding glass windows or sliding glass doors.

Abstract: The hold down apparatus securely engages a unit onto a tray. The tray includes an opening having a front block on the underside of the tray at the opening. The front block also includes a pin. The apparatus comprises a housing having an internal space and is placed in the unit such that the housing space is opened to an opening in the bottom of the unit. A control shaft extends from outside the apparatus and into the housing space to the backplate of the housing. The portion of the control shaft in the housing space is threaded. The external portion of the control shaft is accessible from the front of the unit. An L-shaped pawl has a foot and a rise, the foot of the pawl having a notch in the front edge of the foot.

Abstract: A brittle thermoplastic molded cylindrical hollow hole seal has a top wall and a depending side wall. An annular external rib snap fits to an annular groove in a hole side wall to secure the seal in place. Axially extending angularly shaped in cross section grooves are on the side wall interior and spaced axially extending slots pass through the side wall. The top wall internally has an eight point star shaped set of ridges and troughs whose points terminate at the side wall forming the interior grooves. Reflective aluminum flakes are in the material to provide a spotty finish. The slots, grooves, ridges and troughs form weakening regions causing the seal to shatter in response to an applied local pressure, for example, exerted by a screw driver for use with a screw plugged by the seal. The spotty appearance is difficult to hide when the seal is broken.

Abstract: An avionics display device having a stowable rotatable locking handle disposed therein for facilitating quick and easy installation and/or removal of the display device.

Abstract: A mechanism for locking a cover to a housing of medium and high speed laboratory centrifuges. The locking mechanism includes an axially moveable locking member which has at least one locking portion adapted to be moved in locking engagement with a locking hole of the cover. The axially moveable locking member is rotatably mounted in the housing and connected with a rotary drive. An advancing mechanism transforms the rotary movement of the locking member into an advancing movement thereof. Preferably said advancing mechanism includes a threaded portion provided on the locking member and in engagement with a projection provided on the housing. The locking member has a portion of reduced cross section which may pass through a slot into the locking hole when the cover is moved to its closed position.

Abstract: A fractional-rotation latching system with retrofit capability which includes, in its most preferred embodiment with reference to an example vending machine environment, a T-handle housing to be connected to a vending machine door, a T-handle designed to be nested at least partially within the T-handle housing, a key-operated cylinder lock contained within the T-handle and including a radial lock bolt, a fractional-rotation post member connected to the T-handle, corresponding receiving assembly connected to the vending machine frame for receiving the post member, thereby creating a link sufficient to secure the vending machine door to the vending machine frame, a rotation limitation assembly connected to the post member which includes a cam washer and a flanged washer located within the T-handle housing, and a guide block interposed between the post member and the T-handle to secure a continuously engaging connection between the post member and the T-handle and to limit axial movement between the T-handle and

Abstract: A keylock system comprising a lock and a key for opening and closing the lock, the key having an outer radial retaining stub protruding radially outward, the lock including a base plate for attachment to a surface of an enclosure, a cylinder rotatably mounted within the base plate, the cylinder having a first end adapted to engage the key, and a second end protruding from the base plate, the cylinder being rotatable between open and closed positions, and retaining sleeve threaded onto the cylinder. The retaining sleeve comprises a plurality of retaining fingers engaged with the cylinder to a low rotation thereof, an immobilizing finger for engagement with the base plate to prevent rotation of the retaining sleeve, and a top annular surface defining an opening having a reduced diameter which allows passage of the key therethrough.

Abstract: An anti-theft latch mechanism is especially suitable for securing vending machines. According to the present invention, a control mechanism (such as a rotatable stud attached to a knob) includes a clutch arrangement by which the control mechanism remotely controls a latch portion. Thus, the control mechanism is not rigidly tied to the remote latch, thereby avoiding possible damage to the latch and relaxing design criteria for the mechanism as a whole. A latch portion prevents vandals or thieves from pushing the door either inward or outward as they attempt to gain entry to the inside of the vending machine. For this purpose, the latch provides a cove in which a catch in the side of the vending machine is enclosed at least partially on all four sides when the door is closed. This cove arrangement substantially prevents the latch from being shaken loose even when the vandal or thief jars the machine.

Abstract: A power latching mechanism for use on automobile closures is disclosed, comprising a pin member, a keeper member having a hollow cylindrical body which receives the pin member, a motor for urging engagement between the pin member and the keeper member, and a spring and associated hardware for selectively retaining the pin member in the keeper member. In one embodiment, the keeper member retentively engages the pin member when the pin member is manually inserted thereinto and is also manually disengagable.

Abstract: A automatic locking and unlocking device for effecting the locking engagement of a lock stud within a stud receiving fixture. The lock device of the present invention is adapted for locking a movable closure member relative to a stationary member, such as a vending machine door to a cabinet, and provides a quick open and quick close locking feature. The locking device includes a lock stud fitted with a t-handle at its outer end, and a nose portion inner end, the nose portion having a pair of opposed pin engagement ledges formed therein adjacent the nose portion, and provided with male threads positioned adjacent to and forwardly of the pin engagement ledges. The stationary member is provided with a stud receiving lock housing which contains a stationary cam sleeve, a rotatable cam sleeve which reciprocates relative to the stationary cam sleeve, and a coupling which is positioned anteriorly of the rotatable cam sleeve.

Abstract: The present invention discloses an automatic locking device for effecting the locking engagement of a lock stud within a stud receiving fixture adapted for locking two complimentary structures together formed by a lock mechanism of the type provided with a lock stud mounted on one of the complimentary structures, the lock stud having a predetermined diametric dimension and threaded along the exposed end thereof, the outer exposed end being terminating in a nose portion which has a diametric dimension slightly in excess of the diametric dimension of the lock stud. A stud receiving locking means is mounted on the opposed complimentary structure and in substantial linear alignment with the lock mechanism. The stud receiving locking means is provided with at least two movable members being normally biasingly urged together and having an apreture formed by the members diametrically sized to be complimentary with the diametric dimension of the lock stud when the members are in the rest position.

Abstract: A structural latch is provided for mechanically joining vehicle coupling mechanisms such as spacecraft coupling and berthing mechanisms. The structural latch is manually operable to join the coupling mechanisms. Each structural latch is configured to be readily removable from the joined coupling mechanisms in the event the latch becomes inoperable so as to effect coupling mechanism separation.

Abstract: A lock operable by a key between a locked condition and an open condition, the lock having a fastener for releasably securing the lock to an object, the fastener being movable between a retracted position wherein the lock is in the open condition and an extended position, a spring for biasing the fastener to the retracted position and an enclosure having an opening adapted to allow the insertion and removal of the key from the lock when the lock is in the locked condition and to prevent the removal of the key from the lock when the lock is in an unlocked condition.

Abstract: An electrical transformer having an integral cabinet with an apparatus for latching and locking the doors of the cabinet. The apparatus is comprised of a three point latch system. The first and second latch points are vertical latch rods which engage sills in the cabinet. The third latch point is a latch plate which rotates with a shaft extending through the first door and to which a handle is attached. In the secured position, the latch plate rotates behind a flange extending from an interior wall, thereby preventing the door from being pulled open. The internal wall divides the cabinet into low and high voltage compartments and forms a structural portion of the cabinet. A bolt extends through the first door, the second door, the latch plate and the flange, thereby preventing the doors from being pulled open and preventing rotation of the handle. A cylinder attached to the first door surrounds the head of the bolt and prevents access thereto.

Abstract: A lock for an automatic vending machine including the combination of a bolt-and-nut locking mechanism and a slide locking mechanism. The bolt-and-nut locking mechanism includes a bolt movably mounted to the door of the vending machine to permit an associated handle to push and insert the bolt in a female-threaded hole of a nut on the casing body of the vending machine for locking at an intermediate level of the door of the vending machine. The slide locking mechanism includes a slide plate which is responsive to rotation of the bolt for sliding longitudinally until the slide plate has been caught by catching means on the casing body of the automatic vending machine, thereby locking the door to the casing body of the vending machine at upper and lower levels.

Abstract: A fastening apparatus operable to secure a pair of work objects to each other and wherein one of the work objects mounts an engagement member, the fastening apparatus having a mount adapted for attachment on the other of said work objects in substantially a predetermined position; and a grasping assembly borne by the mount and operable to expand upon movement of said engagement member therewithin and subsequently to contract for engagement with said engagement member to interlock the work objects.

Abstract: Locks securely close a commercial electric power meter box at the front of the meter box where it is visible by a meter reader. One version of the lock readily indicates unauthorized entry into the meter box by extending the seal to the front of the box. Another version of the lock requires a special tool to remove the lock in addition to extending the seal to the front of the box. Yet another version of the lock is equipped with a fully enclosed and protected cylinder lock, which cannot be opened without a special tool and a key even if the seal is broken. All of the locks can be easily installed on existing commercial meter box installations.

Abstract: A fast-acting clamping device for releasably connecting first and second components includes a bolt passing through an opening in the first component and having one end with a head and another end with an anchoring device anchored in an opening in the second component. A cylinder is disposed on the first component, a piston is disposed in the cylinder and a rod is connected to the piston. A lever configuration is connected between the rod and the bolt for generating a clamping force between the head and the first component when a pressure medium is applied to the cylinder.

Abstract: A captive screw assembly for impeding the removal of a screw from a housing or other part. The assembly includes a housing having a hole and an annular flange projecting inwardly in the hole at a location spaced from the hole's two ends. A screw encircled by a coil spring extends through the housing hole with the spring being retained between the screw head and the inwardly-projecting flange. A stopnut, which is sized to be freely received in the housing hole, is threaded to a selected location on the screw. The screw is urged longitudinally upwardly from the housing by the coil spring, to a point where the stopnut abuts against the inwardly-projecting flange. A full removal of the screw from the housing is thereby impeded.

Abstract: A security device for securing a sliding window or door in a sliding window or door and frame assembly. The security device is positioned at an upper region of the sliding window or door and frame assembly to prevent removal of the sliding window or door from the frame when such removal is attempted.A method for securing a sliding window or door and frame assembly using such security device, along with a sliding window or door and frame assembly incorporated such a security device are also described.

Abstract: Apparatus for sealing a postage meter is disclosed. The sealing apparatus includes a member with a cut-out portion. The cut-out portion includes two cover tab receiving openings which are positioned diametrically across from each other. The center of the cut-out portion has a bore hole that runs completely through the thickness of the cover. An insert is provided with is adapted to fit into and mate with the bore hole. The insert contains an opening which will accept a screw and also contains upwardly extending tabs. A screw is used to fasten the sealing apparatus to the postage meter.A cover is stacked over the upwardly extending tab of the insert. The cover is welded to the upwardly extending tabs thereby making it impossible to remove the screw without first drilling a hole in cover and thereafter prying the cover off to expose the screw. A broken or fraudulent cover will indicate that the meter has been tampered with.

Abstract: The two-step locking system includes a dual locking unit comprised of a flat plate to which a recessed cover is hinged. The plate has a keeper projecting therefrom and said recessed cover has a slot through which the free end of the keeper extends so that a padlock can be attached to the keeper via a hole therein to prevent the cover from being opened. A sleeve is secured to said plate, the sleeve projecting a lesser distance from the plate than the keeper, so that the sleeve is completely concealed when the cover is closed. A penta-head bolt extends through the plate of the unit into threaded engagement with a tapped hole in a bracket. The plate of the dual locking unit is riveted to one component of a two-component enclosure, and the bracket is riveted to the other component. The tapped hole in the bracket is in registry with the bolt when the two components are mated so as to allow the bolt to be threadedly engaged with the bracket.

Abstract: A latching mechanism for an automotive vehicle and, in particular, a convertible-type or a movable-type vehicle includes a three-dimensional, two-component positionally adjustable assembly which is mounted to the vehicle and includes a screw-type projection which is received in a keeper disposed proximate the windshield header of the vehicle. A handle is permanently affixed to the pin to facilitate rotation of the pin into and out of the keeper for latching and unlatching, as desired.

Abstract: A tamper-proof bolt including a shank with a threaded end portion merging into an unthreaded portion of lesser diameter merging into an enlarged unthreaded portion merging into the larger base of a frustoconical head also having a smaller base, an undulating curvilinear groove in the smaller base, an island having lobes within the groove, an outer side in the groove, an inner side in the groove formed by the sides of the lobes of the island, and a cylindrical boss on the island extending axially outwardly from the smaller base and having a radial dimension which is approximately equal to the minimum radial dimension of the undulating groove.

Abstract: A device which is installed as additional hardware and which allows two doors which are separated from each other in a common frame to be secured together and tightly against the doorjamb by engagement of parts mounted on the doors. A spindle with a handle on the interior side passes through the inner door to engage a fixture on the outer door and draw the doors together. A biasing spring and a keeper on the spindle in the space between the two doors are covered by a tamperproof housing which supports and allows axial movement of the spindle for engagement and disengagement with the fixture. The device is easy to engage and disengage by rotation of the handle. The spring clears the end of the spindle from the fixture by inwardly axial movement of the spindle when it is disengaged so that the pair of doors can be opened in the usual fashion with the usual hardware.

Abstract: A safety latch assembly has a rotatable grip rotatably mounted on a stationary handle and a ring-shaped flange surrounding a substantially cylindrical portion of the stationary handle, an elastically resilient arresting means on the cylindrical portion whose exterior is formed with an arresting face with which a stop face on the inner side of the grip flange engages upon rotation of the grip in the opening direction from the closed position when the arresting means is in the normal position. The grip is arranged so that the arresting means can be actuated through the flange of the grip to disengage the arresting face from the stop face.

Abstract: A heat insulated manually portable container for dispensing molten plastics material and having a movable piston within a cylinder, a heater for plastics material and a closure equipped with a locking means. The locking means is exteriorly positioned of the reservoir and comprises pairs of complementary screw-threaded members which are engageable through aligned slots in the closure and a body defining the cylinder. The members of each pair are movable along the slots to a quick release position which allows for withdrawal of the members through the closure slots upon opening of the closure.

Abstract: A holder for removably receiving a plurality of magnetic memory disks and for holding the disks in a vertical stack. The holder includes a base having a center post secured thereto and extending upwardly therefrom. The post is adapted to receive the magnetic disks thereon with the disks being arranged on the posts in generally parallel, horizontal planes and separated from each other by ring-like spacers. A nut is removably mounted on the post for locking the disks in place. The nut has a number of spaced projections on its inner periphery for engagement with spaced, circumferentially extending screw thread segments on the outer surface of the post. The segments are spaced from each other to present recesses for receiving the projections on the nut when the nut is first placed on and moved axially along the post until the nut rests on the uppermost spacer. By rotating the nut through a finite angle, such as 30.degree. to 95.degree.

Abstract: A latch assembly including a female funnel-shaped member for guiding a clamping pin into the locking receptacle at the closed end of the funnel for preventing improper thread engagement. The latch assembly includes a centering arrangement in both the pin and funnel supports for providing alignment without restricting in-flight lateral movement of trailing edge access doors on outboard struts containing spring beam attachment to the wing.

Abstract: A device for locking a rectangular electric meter box having an openable front cover. The device has an L-shaped lock housing which includes a first leg fixed to the front cover of the box and a second leg which is detachably fastened to the side wall of the box when the front cover is closed. A barrel lock is inserted into the second leg of the lock housing to block unauthorized removal of the detachable fastener from the side wall of the meter box.

Abstract: This invention provides a hingeless safe door assembly that can be flush mounted in a recessed safe compartment built into a wall or floor. Thus, a frame and flush cover plate holds the door assembly recessed away from the wall or floor for access to locking and latching mechanisms integral in the removable door.A latch bolt operating mechanism axially moves a master bolt, and other slave bolts are similarly axially moved by a pivoted lever that engages both the master and slave bolt for concurrent axial movement between latched and unlatched positions.

Abstract: This invention pertains to a screw-nut mechanism for clamping two work pis together. In one application the mechanism is used to clamp a cover plate over an access opening in a vehicle hull or similar member. The screw-nut mechanism is specially designed for use where one face of the hull or similar fixed work piece is inaccessible for welding or otherwise affixing the nut on the concealed face of the inaccessible work piece. I provide a screw-nut mechanism that avoids the necessity for affixing the nut to the work piece. In my invention the nut is a loose hardware item that can have a thread length proportional to the expected load, thereby avoiding strength problems associated with the formation of threads directly in relatively thin work pieces.

Abstract: A reversing ratchet lever assembly for driving a bolt or other threaded element to be turned selectively in clockwise and counterclockwise directions about a lever axis. The assembly has a housing that defines a bore coaxial with the lever axis and that receives a drive head for the bolt or other fastener. The drive head has radial external ratchet teeth that are adapted to be engaged by a double pawl pivotally mounted in the housing. The pawl is adapted for movement between forward drive and reverse drive engagement with the ratchet teeth and has an intermediate disengaged position. The assembly is operated by a lever handle adapted to be grasped by an operator. The handle has an inner end received in and retained in the housing for pivotal movement about a longitudinal twist axis located perpendicular to the lever axis.

Abstract: An arrangement for securing a housing cover, especially useful for securing a cover for a switch box having electrical switching devices therein includes at least one screwable element which can be threaded to the housing and which is secured undetachably on the cover by a stop on its shaft. The shaft extends through the cover, each of the screwable elements extending through a bottom of an indentation in a surface of the cover. A pre-stressed compression spring is disposed in the indentation between a shoulder of the screwable element and the base of the indentation. Each screwable element comprises a shaft nut, the shaft nut having a shaft with an indentation in its pressure-receiving face. The shaft engages with a threaded pin attached to the housing and rests against a structural part which is supported against a support attached to the housing. The screwable element is centered by a centering body positioned directly ahead of the support on the threaded pin.

Abstract: A method of forming mounting for an inspection cover or similar in a sheet metal tank wherein threaded fasteners such as machine screws are inserted in holes burst in the sheet metal around the edges of the opening in the tank wall. The burst metal portions are then pressed into the thread of the screws to hold the screws in place as studs for the mounting of the cover. A reinforcing flange is simultaneously pressed into the sheet metal around the periphery of the opening.

Abstract: A slidable door is fastened in a stationary relationship with respect to its door frame by a mounting plate rigidly attached to the frame, elongated socket connector pivotally mounted at one of its ends to the mounting plate and extending toward the door handle, and a locking element comprising a door handle engagement portion connected to the door handle and a tongue projecting therefrom and extending into the opening of the socket connector. The tongue and socket connector have interengaging lock elements that are biased into engagement with each other by a set screw and/or spring means.

Abstract: A security locking assembly for substantially preventing unauthorized removal of the bolt securing two members together, the security locking assembly comprising a locking assembly housing secured to the two members by the bolt; a pin, having a first end portion and a second end portion, extendable through a portion of the locking assembly housing; a locking device engaging the first and second end portions of the pin to prevent unauthorized removal of the pin from the locking assembly housing without destruction of a portion of the pin and/or the locking assembly housing; and a cover assembly cooperating with the locking assembly housing and the pin to prevent access to the bolt securing the two members together.

Abstract: A security locking assembly for substantially preventing unauthorized removal of a bolt securing two members together, the security locking assembly comprising a locking assembly housing having a bushing assembly operably disposed in the locking assembly housing for rotatably mounting the locking assembly housing to the two members by the bolt; a pin having a first end portion and a second end portion, extendable through at least a portion of the locking assembly housing; a locking device engaging the first and second end portions of the pin to prevent unauthorized removal of the pin from the locking assembly housing without destruction of a portion of the pin and/or the locking assembly housing; and a cover assembly cooperating with the locking assembly housing and the pin to prevent access to the bolt securing the two members together.

Abstract: A carburetor idle speed set screw is enclosed by an assembly that prevents access to the screw so long as the assembly is in place, and, therefore, prevents adjustment of the set screw; the assembly includes a lower cup-shaped base member nested with an inverted cup-shaped cap having resilient fingers insertable within the lower member and held therein in a spring-lock detent-like manner by mating beads or dimples.

Abstract: A screw lock permanently mounted on a sliding panel includes a finger engageable means mounted on a lock bolt threaded at its distal end. A spring biases the bolt to an unlatched position. A keeper member formed with a threaded opening is mounted on a fixed panel for registration with the threaded lock bolt in the closed panel position. A flange on the sliding panel interlocks with a flange on the fixed panel in the closed position.

Abstract: A lock housing permanently mounted on a sliding panel houses a screw type lock. A keeper formed with a threaded opening is mounted on a fixed panel for registration with the threaded lock bolt in the closed panel position.

Abstract: A lock member projects perpendicularly from the inner surface of the top of a toilet tank cover into the tank and has a bore formed therethrough. A lock rod passes through the bore through the lock member and bores formed through the front walls of the toilet tank in alignment with the bore of the lock member. The lock rod has a threaded part coupled in the bore through the front wall of the tank and a head having keyholes formed therein for accommodating a special key whereby the lock rod is rotatable by the key to insert it through the bores of the tank and lock member and to remove the lock rod from the bores.

Abstract: A panic latch for a grate or other covering for a window or other opening in a building which securely fastens the grate over the opening, yet immediately releases when acted upon by a person inside the building who desires to exit through the opening.

Abstract: A door security latch is disclosed including a link member pivotably attached to the door frame on the inside of the door and which is swingable to a position overlapping the inside face of the door. The link carries a threaded stop having a door face engageable portion which can be screwed into abutment with the door face.

Abstract: A screw lock assembly is provided for sash windows. The lock comprises a self-tapping screw for insertion into aligned apertures formed in the abutting frame members of the window. The aligned apertures are open at one end adjacent the inside of the window and the inner aperture has a substantially enlarged portion at the open end. A cup washer is countersunk by positioning in the enlarged portion and the head and flat washer of the screw is recessed into the cup washer to limit accessibility to the head when the screw lock is in the operative position. Circular ridges are formed on the underside of the flat washer and serve as a locking means by frictionally engaging the adjacent face of the cup washer. The head and flat washer is integral with the screw and the head is made tamper-proof by the act that it is a cylinder with a single, substantially ninety degree flattened side. A key is provided having a corresponding outline for driving the screw.