Abstract: The present invention generally relates to devices for limiting the movement of hinged panels such as doors and more particularly to a door stop that can be mounted directly on a door hinge. The door stop comprises a continuous sleeve having a semi-cylindrical inside surface surrounding the hinge barrel and two contact surfaces to engage the hinge plate of a hinge to prevent the door from opening beyond a predetermined angle. Preferably, one contact surface has a greater surface area than the other contact surface. At least one end plate containing a pin aperture is attached to one end of the sleeve. The pin aperture is sized to receive a standard hinge pin shaft therethrough.

Abstract: A holding device (10) for a door (12) on hinges (14) in a doorway (16) of a room (18) in a building (20) comprising a plate (22). A facility (24) is for mounting the plate (22) over one of the hinges (14) of the door (12). The door (12) will be kept ajar, to allow pets, small children and crawling babies to enter and exit through the doorway (16) in a safe manner. The holding device (10) will also keep a basement door ajar to allow cats freedom to use their litter boxes when needed.

Abstract: A decontamination device (10) including a housing (12) and a chamber (16) for receiving articles to be decontaminated by at least one of washing, disinfecting and sterilizing. A control pad (20) for an operator to input control instructions for controlling decontamination cycles to which the articles are subjected. The control pad being disposed adjacent an exterior of the housing and being accessible to the operator through an opening (24) in the housing (12). A door (30) covering the opening (24) and being hingedly attached to the decontamination device by a mechanism (26) disposed entirely within the housing when the door is in a closed position. The mechanism (26) can be a leaf spring (36) having a first end connected with a pivot pin (42) to the door (30) and a second end secured to an internal region (40) of the housing (12).

Abstract: An automobile hinge structure has one of a hinge male member and a hinge female member configured by side pieces which have hinge pin holes and are arranged in parallel with a space therebetween, a vertical front piece for connecting the side pieces, and a base piece. The front piece is disposed to be substantially orthogonal with the base piece in a plan view. Such hinge structure has an L-shaped plan view and a square C-shaped vertical cross section with reduction of plate thickness and weight of hinge members, high strength and high rigidity. The reduction in the plate thickness facilitates forming and simplifies a forming mold.

Abstract: A hinge for supporting a heavy door on a support. The hinge has a main block mounted on the support and a pair of parallel plates mounted on the door. An extender link and a rotation control link are each pivotally mounted to the main block and between the parallel plates. When the door is in the fully closed position, the main block supports the upper parallel plate. When the door is in the fully opened position, the extender link is interlocked with the rotation control link and supports the door. A compressible seal is formed between the door and the support by a sealant disposed about the perimeter of the door. The compressible seal is not exposed to shear forces.

Abstract: A stop particularly adapted to keep a pivoting member of an automobile, such as a door, ajar so that it is out of contact with the automobile frame during painting, is made of a unitary piece of a thermoplastic material, such as polyphenylene sulfide. The stop can be formed through an injection molding. The stop has a generally elongated body with at least one brace portion adapted to engage a post section of the frame. The stop further has at least one hem flange slot extending generally in the direction of the elongated body, which slot is adapted to receive a hem flange section of the frame. At least one locator extends laterally from the elongated body and is adapted for insertion to a locator opening adjacent the post section. At least one abutting portion extends laterally from the elongated body and is adapted to abut against a portion of the pivoting member to keep the pivoting member from engaging the hem flange.

Abstract: A wiper arm for cleaning windshields of motor vehicles. The fixing portion of the wiper arm is formed from sheet metal in a manner which is economical and strong.

Abstract: A hem flange door stop for use in painting an automobile includes a body, a protruding member contiguous with the body and forming a hem flange groove with the body, a brace contiguous with the body and forming a post slot with the body, and a locator proximate to the brace. The hem flange door stop can further include a stabilizer bar attaching hole formed in the body and can be part of a hem flange door securing system, which includes the stabilizer bar. Also provided is a method of stopping a door including the steps of positioning a hem flange within a hem flange groove such that a post is secured within a post slot and positioning a locator into a post hole. As a result, a stop is fixedly positioned such that a door is prevented from moving beyond a predetermined position relative to the hem flange.

Abstract: An energy storing spring joint (100) for use between two parts movable with respect to each other and joined by the energy storing spring joint is capable of storing energy in such a way that energy is stored in a displacement path and is released in very precise and predetermined manner, with a variable force over the path of displacement, when the parts move in the opposite or backward direction in the path of displacement. At least one energy storing member (50) or at least two energy storing members (50) connected sequentially or at least two different energy storing members (50) connected in parallel are mounted in or on the energy storing spring joint (100) and may be moved by or loaded with energy when one of both parts (30, 40) is moved relative to the other part. The energy storing member(s) (50) may be locked against releasing their energy.

Abstract: There is disclosed a novel Indexing Hinge which rotates when a plunger is depressed and locks when the plunger is released.

Abstract: A locking device for securing plates of a hinge together to preclude opening of an associated door. The inventive device includes an encapsulating block positionable over pivoting cylinders of a hinge to capture and retain plates of the hinge in an abutting relationship. The encapsulating block is shaped so as to define a flat engaging wall and an angled engaging wall which abut the door and an adjacent wall to further resist opening of the door.

Abstract: A hinge arrangement for a gaming device includes a hinge pivotally connecting a cabinet access door to a cabinet. The cabinet access door and the cabinet form a gap therebetween adjacent the hinge when the cabinet access door is closed, but the hinge forms a pocket-shaped barrier around the gap preventing unauthorized access through the gap into the interior of the cabinet. Further, an edge of the cabinet pivots into the pocket and engages a side of the pocket-shaped barrier when the cabinet access door is pivoted 90.degree. to the open position, thus preventing the cabinet access door from pivoting beyond 90.degree. damagingly into an adjacent gaming device.

Abstract: A door hinge with an integrated locking device for yielding positioning of a door at predetermined angles relative to a frame of a motor vehicle comprising: a first hinge part having a base part, a bending spring with three U-shaped sections mounted on the base plate of the first hinge part, a second door-side hinge part having rotatably disposed rollers thereon and wherein the rollers deform the bending spring when the second hinge part is swivelled relative to the first hinge part.

Abstract: An orthotic caliper having at least two lockable steels for attachment to the respective limb members of the human body and having a locking pivotal connection between the steels, characterized by a releasable locking member which can be loaded in compression by the steels and which acts directly on at least one of the steels, and preferably on both of them, to lock them in a desired position when so loaded.

Abstract: A wiper arm for cleaning windshields of motor vehicles. The fixing portion of the wiper arm is formed from sheet metal in a manner which is economical and strong.

Abstract: A flush hinge for pivotally connecting a door to an adjacent wall wherein first and second hinge members are connected by a pintle to move about a pivot axis. The pivot axis is substantially centered in the width dimension of each of the first and second knuckle portions and an inside face of each knuckle portions forms a stop face for the door or wall to position them inside the pivot axis so the ends of the hinge members remain in close proximity as the first hinge member moves. The first and second hinge members have a tongue and groove fitting and stop faces that abut to hold the hinge member in both open and closed positions. In a first embodiment the pivot axis is substantially centered between adjacent edges of the door and walls with an inner face of the hinge being in the same plane as the door and wall to fill a gap therebetween. The first embodiment has a base portion that extends into a hollow wall support and fastens to the inside thereof.

Abstract: A foot operated double acting lever for rotating a lid hinged to a base from a first position to a second position such as lifting the seat of a toilet bowl without touching the seat with the hands wherein the lid (or seat) is locked in the second position when the pedal is not depressed thereby maintaining the seat in its second position and is unlocked by depressing the pedal a second time and allowing the lid to rotate back to its first position at a speed that is under control of the foot on the pedal. The device includes a rotating housing coupled to one end of the lever (opposite the end with the pedal) that is coupled to a drive gear that turns a hinge gear mounted to rotate on the same axis as the lid. In order that the lid be locked in the second position, a lock catch engages the drive gear and a fixed slot thereby locking the drive gear.

Abstract: A storage area and hinge structure having two stopper portions for opening and closing a lid relative to an opening in the box. The hinge has two stopper portions cooperating with the box for relieving force on the hinge and storage area when the lid is opened fully.

Abstract: A blackboard includes a rectangular board member, a protective frame member provided on each side of the board member, and a tray connected to a lowermost one of the frame members and movable between an unfolded position for receiving erasers and writing implements and a folded position. The lowermost one of the frame members has a front side which is formed with a longitudinally extending retaining portion that confines a longitudinally extending space which is substantially L-shaped in cross-section. The tray has a rear side wall which is formed with a transversely and longitudinally extending rearward anchor projection that is substantially T-shaped in cross-section and that has a head portion which extends into the space.

Abstract: A catcher for use in a component stacker for holding stacks of product die-cut from a continuous sheet of material. The catcher includes two catcher plates attached to a pivot pin for upward and downward pivoting between generally horizontal and generally vertical positions, thereby providing support for adjacent edges of two adjacent stacks of product.

Abstract: A glove box is pivotally mounted at a lower end thereof in an opening defined in an instrument panel. The glove box is angularly movable from the opening to an opening limit position in which the glove box is locked and partly opens the opening. The opening is defined by a partition assembly which includes a side partition having a rail. The glove box has a roll rotatably mounted on an arm coupled to a shaft rotatably supported on the glove box. When the glove box is in the opening limit position, the roll is engaged by the rail. To service an accessory device, such as the inflator of an air bag or the filter of an air-conditioning unit, disposed behind the opening, the shaft is rotated to turn the arm to displace the roll out of engagement with the rail, thus allowing the glove box to be tilted from the opening limit position to a fully open position in which the glove box fully opens the opening. The serviceman can now reach the accessory device directly through the opening.

Abstract: A hinge for a vehicle includes a stationary sheet metal hinge base adapted to attach to a vehicle, a sheet metal panel bracket adapted to attach to a vehicle panel, and a sheet metal hinge member operably connecting the hinge base and panel bracket. The panel bracket is slideably attached to the hinge member and movable between an extended position and a retracted final assembly position. The hinge member is also pivotally connected to the hinge base and rotatably movable through an arcuate path including a panel open position, a panel closed position and at least one intermediate position therebetween. The hinge member, when the panel bracket is in the extended position, is movable to the intermediate position in the arcuate path so that the panel is spaced from the vehicle to facilitate painting of the panel and the vehicle. The hinge member, when the panel bracket is in the retracted position, is movable to locate the panel relative to the vehicle in a final assembly position.

Abstract: The hinge for the hood of an agricultural tractor includes a reversing plate pivotally mounted on the vehicle body. A first hinge arm has one end coupled to the reversing plate and a second end coupled to the hood. A second hinge arm has one end coupled to the vehicle body and a second end coupled to the hood. The reversing plate is rotated by a manually-operated lever mechanism. A lock mechanism near a front end of the hood retains the hood in a closed position and releases the hood only after a first opening phase, after which the hood can be fully opened during a second opening phase. A gas spring is coupled between the vehicle body and the reversing plate. In the closed position the gas spring helps to hold the hood in the closed position. The gas spring helps to open the hood after the reversing plate is rotated by a certain amount beyond a neutral position.

Abstract: Utility clamp for use in a laboratory or other environment containing caustic elements. The clamp has a fully-enclosed hinge which is isolated from the environment. The critical hinge components such as the hinge pin and coil spring are internally located in the hinge and are protected from corrosion or attack by agents which might contact the clamp during normal use. A method is also provided for assembling the clamp whereby pre-loaded springs are positioned within the internal cavity to normally bias the jaws of the clamp in an open position relative to each other.

Abstract: A hinge for a foldable rail section for mounting a container of an oxygen supply unit in an aircraft, with a first hinge part on the rail section and a second hinge part on the edge of the container, and with a container door, which extends in parallel to the longitudinal side of the rail section and is pivotable around a joint on the rear edge of the container. The connection of the hinge to the container is simplified, and a stop is provided for the container door.

Abstract: A motion limiting device for hingedly connected storage containers which includes a motion limiting protrusion, an arcuate slot, a rib, and an arcuate groove. The motion limiting protrusion and the rib are abutted and formed in the rear sidewall portion of a first member. The arcuate slot and arcuate groove are correspondingly shaped and formed in the rear sidewall portion of a second member such that the motion limiting protrusion and rib become matingly engaged with the arcuate slot and arcuate groove respectively when the first member and second member are hingedly connected.

Abstract: The body structure of a pocket computer includes a fastener mainly an elastic fastening element of a multi-layered construction accommodated in an insertion space located at a front edge of the main body housing. A simplified telephone input jack is constructed in the side wall of the pocket computer main body. The association of the main body and the cover body of the pocket computer is accomplished by a pivotal shaft, which is characterized in that it is provided with a delay swivel device permitting the communication cables linking the main body with the cover body to be less vulnerable to bending caused by the actions of opening and closing the cover body and that it includes indicator lights serving to show the operating status of electronic functions of the computer. The keyboard includes entry keys which are securely coupled with the housing plate of the keyboard by slide keys and slide key mounts.

Abstract: Support structure for a refuse can comprises a base support adapted to receive the flange of a conventional refuse can. A locking bracket comprises a male member fixed to the can and fitting within an aperture in a female member mounted on a support structure and lockable therein, to prevent the refuse can from being removed from the base support. The lid of the can may be hinged to the support structure or to the can, to encourage users to replace the lid over the open end of the can.

Abstract: A hinge, in particular a folding door hinge, includes a hinge arm which may be mounted by means of a base plate on a furniture unit part. The hinge arm may be adjusted in two dimensions on the base plate and is connected via at least one joint pin to a hinge pot. An end of the hinge arm facing the joint pin is angled and mounted on such end is a linearly displaceable extension member that carries the joint pin.

Abstract: A mechanism for opening and closing an openable apparatus has a body consisting of a first body portion and a second body portion. The first body portion is rotated about a pivotal axis between the closed position and the fully opened position. An arcuated gear portion having a center falling on the pivotal axis is provided. A one-way damper mechanism is connected to the gear portion directly or via a transmission gear and comprises a rotary gear rotated in cooperation with the opening and closing movements of the first body portion and a rotational speed control device for controlling the rotational speed of the first body portion when the first body portion is closed. In cooperation with the movement of the first body portion between the closed position and the fully opened position, the rotary member is rotatable about the pivotal axis between a first position at which the first body portion is closed and a second position at which the first body portion is fully opened.

Abstract: A concealable architectural hinge assembly has a mounting bracket with a U-shaped body which seats within a recess in the door jamb and a pair of flanges at its outer ends which extend along a face of the jamb. The mounting portion of one hinge leaf is secured to the bracket base wall and its knuckle portion is along its side edge in the direction of door opening movement, and it extends angularly outwardly to provide an offset barrel portion. The second hinge leaf has a generally U-shaped body with its mounting portion disposed against the edge of the door. It has a displacement or center portion which extends toward the other side edge of the first hinge leaf, and its arm portion extends substantially parallel to its mounting portion. The knuckle portion of the second leaf extends angularly from the plane of the arm position to provide an offset barrel portion aligned with that of the first leaf.

Abstract: A door prop device for the purpose of maintaining a hinged door in a propped-open position against the forces of spring tension, wind, gravity, or other causes, which will effectively function without damaging either the door or any adjacent structure and which will function on doors which pivot on vertical axes, horizontal axes, or any pivot axes orientations between vertical and horizontal. The device comprises a block-shaped prop member and a retainer member attached to the prop member. The retainer member is adapted to be placed over and engage with a hinge pin of an opened door hinge whereby the prop member is caused to assume an obstructing position in the space between the separated plates of the opened hinge. When it is desired to close the door, the door prop device is simply removed from the hinge and the door may then be closed.

Abstract: An adjustable door stop for a hinge mounted door having at least one hinge leaf connected to the door, one hinge leaf connected to a doorway, and a hinge pin. A body receives the hinge pin in order to rotate substantially perpendicular to the axis of the hinge pin. An adjustable mechanism extends from the body and rests against the doorway. A finger extends from the body substantially parallel to the axis of the hinge pin so that the hinge leaf connected to the door may rest against the finger, thereby stopping movement of the door.

Abstract: A locking hinge mechanism for concrete forms includes parallel hinge strips connected together by hinges positioned at intervals along the length of the strips. Each hinge includes provision for a wedge lock which, when fully inserted, positions the hinge strips at a secure 90.degree. angle. The hinge strips are spaced apart from the juncture of the strips, when arranged at the 90.degree. angle, so that concrete flashings do not clog the hinge. The hinge strips are in turn affixed to the side rails of the joining concrete forms to form a 90.degree. angle, such as for a column form arrangement.

Abstract: The invention is a hinge assembly made of two parts, specifically for an accelerometer. The first part is adapted to be attached, either directly or through a bracket, to an inertial acceleration sensor. The second part is adapted to be rigidly attached to an apparatus whose acceleration is to be measured. The two parts are connected by a flexible hinge.The invention resides in the placement of the hinge and in the attaching means for the second part of the hinge frame as well as in the method for fabricating the novel attaching means.The hinge is not attached to the center of the opposing edges of the first and second parts of the hinge frame. It is attached to one end of those opposing sides at a first region of the second part of the hinge frame. The hinge line is generally parallel to those opposing sides.The second part of the hinge frame is clamped only in a second region away from the hinge.

Abstract: A duct assembly for enclosing conduits, cables, wires, lines and the like, comprising a base having a generally U-shaped cross section along its longitudinal axis, and a cover having a generally U-shaped cross section along its longitudinal axis. The base includes a generally planar central portion with first and second legs extending substantially perpendicular thereto. The cover includes an intermediate portion having third and fourth legs extending substantially perpendicular thereto. The cover is pivotally and releasably coupled to the base at one end and releasably coupled to the base at the other end. The pivotal and releasable coupling is made up and released via a snap fit resulting from forces exerted substantially perpendicular to the longitudinal axes of the cover and the base. The pivotal coupling allows angular movement of the cover relative to the base through about 45.degree. to about 60.degree..

Abstract: An improved play yard having a lower horizontal support formed of rails, an upper horizontal support formed of rails and vertical support rails pivotably coupled therebetween, a central hub pivotably coupling the radially interior ends of the rails of the lower horizontal support and hinges coupling the rails of the upper horizontal support at intermediate locations. The hinges are adapted to be rotated about their axes between a locked position wherein the play yard is secure for operation and use and an unlocked position wherein the upper rails may be pivoted and the entire play yard collapsed upon the raising of the hub. Also disclosed is the hinge per se.

Abstract: A hinge is provided between bodywork and a door of a motor vehicle. A stationary bracket is fixed to an upright of the bodywork and includes a base with a hole. A movable bracket is fixed to the door and a pin connects the stationary and movable brackets. A torsion bar has a wheel/cam follower for engagement with a cam on a connection element. The stationary bracket, torsion bar, cam follower and connection element comprise a sub-assembly and the cam and cam follower are located intermediate the height of the hinge. The movable bracket includes a boss with an opening. Upon linear movement in a direction parallel to the hinge axis, the boss may be disposed about the pin with a connection element and movable bracket cooperable to prevent relative rotation therebetween whereby accurate assembly is achieved.

Abstract: A pistol holster with a limiting swing clutch having the holster and belt-loop separated from one-another by the engaged swing clutch face-to-face elements, all held in a tightly compressed state susceptible of limited flexing movement against a flexible leather washer, all mounted on a female bolt's female-threaded shaft between underface flat surfaces of the heads of the female bolt and the mated male bolt.

Abstract: An easel hinge for supporting picture frames and the like comprises two hinge plate members each including a tubular wall. The tubular wall of one hinge plate member is inserted in the tubular wall of another hinge plate member with at least some non-congruent portions whereby the inner tubular wall can be rotated within the outer tubular wall. The outer tubular wall is open and has at its open edge a substantially straight lower end wall portion. When the inner hinge plate member strikes against the substantially straight lower end wall portion of the outer hinge plate member the plates are retained in the end angular position, and further angular displacement of the hinge plate members relative to each other is prevented.

Abstract: A mechanism which prevents a door from closing by blocking the door hinge from closing.

Abstract: A hasp-type latch includes a hasp member with a base having a base wall and a pair of upstanding side walls and a latch arm which is pivotally mounted thereon. The side walls of the pad include releasable latching elements which are engageable with the arm in its open position to hold it in that position. The staple member has a base with a top wall and a depending sidewall defining a cavity thereunder, and the top wall has an opening therethrough. A post member has a pedestal portion which extends through the opening into the cavity of the staple base, and a post portion which extends upwardly through the aperture in the arm in its closed position. The pedestal portion includes securing means in the cavity which extends outwardly beyond the opening in the top wall to prevent the post member from being pulled through that opening. Generally the post member is rotatable to locate an elongate axis so that it overlies a portion of the hinge leaf in the closed position and prevents its being pivoted upwardly.

Abstract: A plastic molded measuring scoop assembly includes a generally cylindrical measuring scoop and a hinged handle assembly which is comprised of a fixed inner handle portion and a foldable outer handle portion. The inner handle portion carries a latching channel at its outer end and the inner end of the foldable handle portion carries upper and lower latching fins. The cooperation between these fins and the latching channel retain the foldable handle portion of the handle assembly in either a folded storage position or an unfolded use position.

Abstract: A folding boat chair formed by a molded plastic seat member and a molded plastic back member. An integral boss on the underside of the seat member presents a socket which fits on the top end of an upright post mounted in the boat. The seat can turn on the post and can be locked in place by a clamp mechanism. Pins which are integral with the sides of the back member fit in passages in sides of the seat member to pivotally connect the members without the need for separate hinge components.

Abstract: A hinge for a sleeper cab compartment door that pivots between open and closed positions about a generally vertical hinge axis. The door frame has a jamb adapted to support a butt hinge and the door has a hinge stile spaced from the jamb when the door is closed so that the respective jamb and stile surfaces are separated by an elongated gap that is closed on the outer side by an elongated skirt portion extending laterally from the front panel of the door an adapted to swing inward into the gap when the door is pivoted to its open position. The jamb leaf of the hinge has a longitudinal bend dividing it into two flat flanges angularly disposed relative to one another, one of the flanges being secured to the jamb and the other forming a bearing for the hinge pin.

Abstract: Hinge mounted doorstops which include channel members having a normally horizontal perforated web and normally vertical opposed flanges on opposite sides of the web mountable on top of door hinge hubs, engaged by the top hinge pin, edges of the flanges engaging the hinge leaves to limit door opening past a predetermined arcuate amount. The hinge mounted doorstops permitting opening of doors in the general arcuate range of 90.degree. to 180.degree..

Abstract: A foldable bicycle support device including first and second cross frame members and first and second bicycle wheel receiving channels extending crosswise of the cross frame members. First and second bicycle support members are pivotally mounted by hinge brackets to the same cross frame member for swinging movement about an axis paralleling the cross frame member, and the first and second bicycle support brackets each have a portion that converges toward a medial plane between the wheel support brackets and laterally extending upper portions that extend transverse to the plane for engaging and supporting a bicycle frame. The converging portions of the bicycle support brackets are rigidly interconnected so that the first and second support brackets form a laterally stable assembly that is movable as a unit between a lower and a raised position.

Abstract: A blocking mechanism for the top and rear lid of a motor vehicle with a convertible top, in which the ends of a cable or of a rod are secured at a distance from the respective lid axis at the top and rear lid and at a pivot part supportable at the body. Additionally, an abutment is formed at one pivot part which, during the opening of the coordinated top or rear lid, acts on the second pivot part. As a result thereof, either an opening of the top or rear lid coordinated to the second pivot part is prevented or, during the opening of the top or rear lid, the respectively other top or rear lid is closed.

Abstract: An infant's amusement device comprises a suspension bar adapted to be supported in a horizontal position during use for suspending a plurality of toys therefrom, a pair of supporting bars disposed in a common plane at the opposite ends of the suspension bar, and a pair of juncture bars joining the supporting bars to the opposite ends of the suspension bar and lying in a common plane with the suspension bar. The latter common plane is at an acute angle of 30.degree.-75.degree. to the common plane of the supporting bars, whereby the supporting bars stably support the suspension bar in a horizontal position on and spaced above a horizontal surface to enable the infant to lie under the suspension bar, parallel to and straddled by the supporting bars, and to touch the toy suspended from the suspension bar. Three embodiments are described, namely a unitary construction, a foldable three-part construction, and a foldable five-part construction.

Abstract: A hinge (16) pivotally connects a lid (14) to a body (12) of a container (10) for releasably holding the cover (14) at both open and closed positions. The hinge (16) has a pair of hinge leaves (22, 22A) and a boss (48) extending from one leaf (22) forms an outer cam surface having a pair of relatively flat cam portions (50, 52) on opposed sides of a high point (54) of the cam. The other leaf (22A) has a lip (42A) extending therefrom with the inner surface of the lip (42A) riding along the outer surface of the cam formed by the one leaf (22) to define a cam follower which forms a latch member. A high portion (54) of the cam by contacting the lip (42A) restrains movement of the cover (14) at both the open and closed positions thereof until an opening force of a predetermined magnitude is exerted against the cover (14) for moving the lip ( 42A) over the high portion (54) of the cam.