Abstract: A filling machine for dispensing sometimes viscous liquid in measured amounts to containers wherein a carrier supports a plurality of individual containers with open upper ends for lateral orbiting movement with a central tank, a pump and valve assembly orbits with the carrier and has a plurality of rotary valves, communicating with outward passages from the tank and with piston pumps, and also communicating the piston pumps with dispensing openings arranged above the containers. The pistons of the pumps are controlled by a pivotal cam track which can be swung to various positions to change the extent of the suction stroke of each piston, when operated by an actuating member. The machine is particularly designed for disassembly and for cleaning.

Abstract: Flexible pouches are advanced continuously around an arcuate path and are filled with food chunks during the advance. A filling apparatus initially deposits the food chunks into metal containers which are circulated to a continuously rotating turret adapted to move the containers around the path in vertical registry with the pouches. As the containers are advanced by the turret, plungers force the food product out of the containers, through funnels and into the pouches. The empty containers then are removed from the turret and are returned to the filling apparatus.

Abstract: A seal for limiting access of bacteria through a side arm of a stopcock such as that used in apparatus for monitoring pressure in a human blood vessel. The seal has a generally cylindrical body, an open end of which slides over the side arm. A portion of the body seals against the side arm exterior wall. The other end of the seal forms a cap through which a syringe nose may penetrate to establish fluid communication between the syringe and the side arm lumen. The interior of the seal body includes a recess for a Luer lock fitting which may exist on the end of the side arm, and an annular spacer projecting from the inside of the body to provide a surface against which the end of the side arm can abut to prevent the inserted syringe nose from bottoming on the end of the stopcock arm during use. A slit in the capped end of the seal facilitates insertion of the syringe nose. The slit is surrounded by a recess to guide the syringe nose into the slit.

Abstract: The application discloses an apparatus and method for selectively cutting trees on plantations, such as might be done for thinning or stocking control. The apparatus may be drawn by a wheeled or tracked prime mover. It comprises an outwardly biasable primary arm mounted on a supporting frame. The distal end of this arm bears a guide means that serves to assist in moving it past those trees that are not to be removed in a manner that prevents injury to the tree. The guide means also acts as a guard for a tree-severing means. When a tree is to be removed the severing means is moved forward in the direction of travel so that it contacts the tree before the guide means. Otherwise, the severing means is prevented from contacting the tree by the guide means. The severing means may be manually deployed or it can be controlled by a simple logic system into which travel speed and take/leave decisions are made. The device is normally used in plantations in which trees have been planted in approximate rows.

Abstract: A mobile device for handling material of various types including a frame having an endless track mounted on each side thereof for providing mobility to the frame. A source of power in the form of an internal combustion engine is mounted directly on the frame. A turntable is rotatably mounted on the frame with a boom pivotally connected at its lower end to the turntable at a point spaced from the rotating axis of the turntable for pivotal movement of the boom in a vertical plane over the turntable by means of a hydraulic ram connected at its lower end to the turntable at a point intermediate the rotating axis of the turntable and the pivotal connection of the lower end of the boom with the upper end of the ram connected to the boom. The turntable is mounted on the frame for pivotal movement of the same with the boom thereon transversely to each side of the device.

Abstract: A wood routing machine accepts a length of wood stock, e.g., a length of preformed crown molding, and thereafter in automatic sequence clamps the wood stock at lengthwise spaced locations, routs evenly spaced notches along the length of the stock and after each router operation automatically unclamps and indexes the stock a predetermined distance, again clamps the stock and repeats the router operation sequence until the entire length of stock has been notched to form a length of dental block type wood molding.

Abstract: Method of manufacturing a deformable fuel cell embodying the steps of providing a flexible mold which has an opening therein. A nut ring secured to the periphery of the opening and a protective plate is attached to the nut ring. Coating material is applied to the mold which hardens to form a body. The protective plate is removed and the nut ring is detached from the mold. The mold is then collapsed and removed from the body through a hole in the nut ring. Ballistic nylon cloth may be applied to the mold before the application of the coating material.

Abstract: A flat, flexible, sterilizable container for a liquid to be maintained and extracted under sterile conditions, said container comprising: a body having walls formed by a three-layer laminate including an outermost layer of a propylene polymer, an innermost layer of a copolymer of ethylene with a small amount of butylene, and an intermediate layer of an amide polymer; and a valve carried by said body comprising an elastomeric core whose spaced major faces are covered, one, by a three-layer laminate similar to said body wall forming laminate and, the other, by a two-layer laminate including a first layer of a copolymer of ethylene with little butylene and a second layer of an amide polymer.

Abstract: A waste receptacle, such as a disposable container, having a collapsible cylindrical bag with an upper rigid shaping ring secured at its upper end and a rigid ringed base member secured at its lower end. A stand includes gripping members which engage exposed portions of the upper ring and the ringed base member for retaining the disposable container in an upstanding position for use in receiving waste.

Abstract: Disclosed is a high hardness rubber composition having a hardness of at least 92, which comprises 100 parts by weight of a rubber, 55 to 95 parts by weight of soft black having an average particle size of 40 to 80 millimicrons, 5 to 30 parts by weight of a thermosetting resin and a small amount of a curing agent, the sum of the amounts of the soft black and thermosetting resin being 60 to 100 parts by weight per 100 parts by weight of the rubber.This high hardness rubber composition is advantageously used as a tire reinforcement for the rim cushion portion or for both the rim cushion portion and bead filler.

Abstract: A window screen arrangement comprises a novel roller combination for winding and unwinding the screen or shade element and at the same time providing for positioning of the entire screen assembly in any desired position vertically on a window to provide partial screening in any part of the window while at the same time permitting additional screening provided by the operation of the screen upon a roller. The method of supporting the screen in the window opening comprises a novel arrangement of cords for support and positioning which permit the foregoing without the use of pulleys, springs, counter-weights, hooks, clamps, or other positioning devices to hold the screen assembly in any given vertical location while permitting its roller features to function.

Abstract: A method for making foundry moulds and cores where after preparation of the moulds and cores having a sand composition of a low strength up to 0.03 MPa, a cooling medium is introduced into the mould cavity, preferably liquid nitrogen, in an amount to provide hardening of only the surface layer of a required sufficient to reproduce the shape of the mould cavity.

Abstract: A method of forming filaments, particularly continuous strips, sheets or the like, by rotating a chill wheel against a meniscus of molten material formed about the periphery of an elongate orifice through which the molten material is fed under uniform fluid pressure along the longitudinal axis of the orifice. Filaments of different widths, thicknesses and composite structures are extracted by utilizing single or plural chill wheels in conjunction with plural orifices.

Abstract: A method of fabricating a structural member such as a wicket gate for water turbines by electro slag forming comprises the steps of mounting a water-cooled metal mold on a part of a previously formed structural member, such as a stem; melting electrodes inserted in the water-cooled metal mold to form the other part of the structural member such as a vane portion of the wicket gate on the previously formed structural member. The previously formed structural member has a concave portion which is exposed in the water-cooled metal mold and the water-cooled metal mold is mounted so as to contact with the previously formed structural member at the lower portion than the top of the concave portion. The previously formed structural member is melted gradually from the central portion of the concave to the outer periphery and then such a portion as the vane portion is formed by molten metal of the electrode.

Abstract: Energy is extracted from geothermal brines by direct contact with a working fluid such as isobutane which is immiscible with the brine in a geothermal boiler. The geothermal boiler provides a distributor arrangement which efficiently contacts geothermal brine with the isobutane in order to prevent the entrainment of geothermal brine in the isobutane vapor which is directed to a turbine. Accordingly the problem of brine carry-over through the turbine causes corrosion and scaling thereof is eliminated. Additionally the heat exchanger includes straightening vanes for preventing startup and other temporary fluctuations in the transitional zone of the boiler from causing brine carryover into the turbine. Also a screen is provided in the heat exchanger to coalesce the working fluid and to assist in defining the location of the transitional zone where the geothermal brine and the isobutane are initially mixed.

Abstract: A tube-in-tube shelless heat exchanger having the capability of being modularized comprises a plurality of single element tube rows 18 in combination with header means 26. The single element tube row 18 comprises a plurality of inner 12 and outer 14 concentric tube pairs for carrying a first and a second heat transfer fluid, forward and aft tube sheets 20, and flexible arcuate manifold means 16 for outer tubes 14.

Abstract: A method of removing ripples from the metal sheet portion of a heat exchanger panel element which is manufactured by joining a metal tube to a metal sheet by means of heated and cooled weld metal, and the product of the method. In the method, the sheet is corrugated, after the tube is joined thereto, without stretching the metal of the sheet by more than 2% so that the sheet length with corrugations is substantially equal to the length of the tube joined thereto.

Abstract: A stripper seal protection and operating tool sealing element and method for protecting stripper seals during drilling operations with operating tools having both polygonal and circular cross sections. The stripper seal protection and operating tool sealing element includes a lower protective sleeve for expanding the stripper seal radially outward to prevent contact with polygonal operating tools and includes a head portion integral therewith for mounting an elastic sealing ring for packing off on the polygonal operating tool. The protective sealing element is particularly useful for applications in diverter housings of the rotating insert type. The protective and sealing element is inserted and removed from the diverter coupling concurrently with polygonal operating tools such as kellies. The protective sealing element also includes rotating lock means to provide common rotation of the rotating insert with the kelly.

Abstract: A method and apparatus as provided for periodically supplying a quantity of fluid containing a corrosion inhibitor or other treating fluid to both the internal and external surfaces of downhole components of a subterranean well. The corrosion inhibitor is introduced in the fluid that normally fills the annulus defined between the well casing and the production string. This fluid is periodically subjected to a cyclic pressure and the cyclic pressure is employed to operate valving apparatus disposed in the vicinity of the packer to periodically inject a quantity of the annulus fluid containing the corrosion inhibitor into a bypass passage extending through the packer and, hence, into the production fluid, which the carries the corrosion inhibitor to internally disposed downhole components in the well bore.

Abstract: This invention relates to an improved method of cementing a casing string in a wellbore where the casing string will subsequently be heated by the injection of steam or by flowing of other hot fluids through the casing. The annulus between the wellbore and casing is at least partially filled with cement. A J-slot is positioned on the lower portion of the casing string. The lower end of a tubing string is provided with a stressing tool and lug, the lug being engageable with the J-slot and the tubing string is lowered into the casing and the lug is engaged with the J-slot. The tubing string is stressed until the cement in the annulus sets, thereby allowing the casing to be set under stress.

Abstract: A method and apparatus for stabilizing an interior surface pipe within an exterior casing pipe are disclosed. The casing stabilizer apparatus comprises a cylindrical separable hanger body made up of a pair of body half-sections. Each body half-section includes tapered exterior walls and an interior bore with serrated teeth therein for gripping a surface pipe placed within said bore when assembled. A downward depending lip portion defining a space for engaging the uppermost end of the exterior casing pipe is also provided on each hanger body half-section. A locking means is provided for securing the body half-sections together. The hanger body is attached to an interior surface pipe above the exterior casing pipe, and then lowered onto the exterior casing pipe.

Abstract: A well tool, such as a packer apparatus, is adaptable for insertion on a conduit within a subterranean well having casing therein. The well tool comprises a cylindrical mandrel which is communicable to the conduit. Slip means are carried exteriorly around the mandrel and are movable into expanded position for anchoring the apparatus to the casing whereby subsequent longitudinal movement of the apparatus in at least one direction is prevented. Seal means are circumferentially extending exteriorly around the mandrel and are urgable into sealing relation with the casing to prevent fluid communication thereacross, the seal means comprising at least one section of transversely compressible seamless, knitted elements generally defined by a continuous series of interlocking ductile metal-containing loop members.

Abstract: An antifreeze arrangement especially for automatic sprinkler systems comprising a frangible membrane, secured to a bellows interposed in the water supply pipe to the sprinkler system, antifreeze solution downstream of the membrane with water upstream thereof, the membrane being one that breaks out but does not separate from the bellows when a sprinkler relieves the pressure on the downstream side. Pressure equalizing piping connections, filling piping, and a specific gravity indicator are provided.

Abstract: The invention is a plant lifting apparatus of the opposed belt type that can be quickly adjusted in the field to accommodate different plant row spacings. The lifting belts are carried on individual supporting frames. These, in turn, are pivotally mounted at their proximal ends to a subframe member. The distal plant receiving ends of the supporting frames are bridged by spreading means which vary the spacing between adjacent pairs of lifting belts. Preferably the outer belt supporting frames are adjusted separately. The inner pairs are bridged by toggles, turnbuckles or similar means that control their spacing within the limits set by the outer supporting frames.

Abstract: A soil penetrating and coring implement is provided and is adapted to be towed by a vehicle across the round surface to remove plugs of soil from the ground. The coring implement comprises a tubular and cylindrical rim having a plurality of circumferentially extending slots formed through it and the slots are both circumferentially and axially spaced from each other. The entire rim is rotatably mounted on an axle which in turn is connected to the towing vehicle. A plurality of elongated mounting assemblies are pivotally secured within the interior of the rim so that the mounting assemblies are circumferentially spaced about the interior of the rim and have their axes parallel to but radially spaced from the axis of the rim. A plurality of tubular coring elements are secured to each mounting assembly so that each coring element extends diametrically through and radially outwardly from one side of the tube.

Abstract: A tool for an earthworking machine in which the machine has a rotor with one or more support plates mounted in an axially distributed relation with each plate carrying one or more earthworking tools in circumferentially distributed relation. Each tool extends radially outwardly from the respective plate and at the outer end has an earthworking portion extending transversely to the plane in which the tool rotates. The forward working portion comprises a foremost impact region and a cutting edge that slopes rearwardly from the direction of rotation as the edges extend away from the impact region.

Abstract: A reversible plough has a headstock formed from upper and lower parts hingedly connected about a transverse axis, the reversing spindle being mounted in the lower headstock part and carrying a crank arm connected by a link to the upper headstock part. As the reversing spindle is rotated, relative hinging movement between the two headstock parts causes the reversing spindle to tilt in a vertical plane, the load in said link counterbalancing to a degree the offset center of gravity of the plough frame and reducing the torque required to reverse the plough frame. The plough frame carries left handed and right handed plough bodies and the center of gravity of the plow frame is laterally offset from the longitudinal axis of the reversing spindle.

Abstract: A tractor-drawn farm implement is carried at its front end on a tractor drawbar and at its rear end by trailing wheel means, and linkage of the so-called four-bar type is operative to selectively raise and lower the implement. The body of the implement serves as one member of the linkage and front and rear lever arms are interconnected by a leveling rod so as to coordinate the front and rear arms as force is exerted against one arm by power-operated means on the implement. During one phase of vertical movement of the implement as it is raised or lowered, the leveling rod is stressed in compression. The invention provides yieldable means in conjunction with the rod capable of yielding as to prevent or at least minimize bending of the rod in the event of over-stressing.

Abstract: Method for drilling well bores into an offshore substrate from a marine platform which is fixed to the ocean floor. The latter is provided with a cage which is removably positioned in a platform leg. A drill conductor carried in the cage guides a lowering drill string into a desired direction away from the platform. The cage is periodically raised and rotated, or provided with a different conductor orientation to permit a variation in the drilling direction.

Abstract: An electronic weighing apparatus includes a switch mounted on a base surface thereof, actuated by an actuating member biased to support a portion of the base. When weight is applied to the apparatus, the actuating member is moved to a depressed position, thereby automatically energizing the apparatus. In addition, a tab is mounted to the base near the switch. Vertical forces can be applied to the tab to depress the actuating member without disturbing the zero position of the weighing apparatus.Furthermore, the apparatus includes an optical coded disc with a plurality of concentric code tracks. A light guide conducts light to a line on the disc which is parallel to but offset from a radius of the disc. Photosensors are positioned on the other side of the disc, opposed to the light guide.

Abstract: An agricultural tractor comprising differential case, a transmission case, a speed change case interposed between the two cases and directly coupled thereto, and a speed change mechanism contained in the speed change case and adapted to provide a great reduction ratio. The speed change case is not integral with the two other cases.

Abstract: A firebox, steam boiler and steam condenser are mounted in a road vehicle such as a passenger automobile. A steam powered drive member, such as a steam turbine, is operated by the steam pressure from the boiler and has drive connection with the drive axle of the vehicle. The vehicle carries a fuel bin for holding a supply of powdered fuel which is fed to the firebox. An electrical system is also associated with the vehicle to produce an auxiliary heating function for the boiler, and such electrical system includes a time control arranged to energize the heating element at a preset time. A temperature control is also provided. A water supply system for the boiler includes an auxiliary condenser to assist the main condenser in the system. Main and auxiliary reservoirs are provided to facilitate adequate storage of water in a compact arrangement.

Abstract: A speaker grille bezel-retainer terminating in a tubular portion with multiple groups of radially intermittent serrations axially displaced to receive a matching bezel ring having an inside diameter with alternate tabs and cut-outs and the tab is shaped to form a ramp to axially advance the ring on the bezel while rotationally engaging spaced, aligned pairs of serrations.

Abstract: An outboard motor includes a cowling with a cavity that receives a carburetor that supplies the engine with an air/fuel mixture. The carburetor has an air intake port. An air intake passage connects to this port, and bends partway around the carburetor. A resonance chamber communicates with the air intake passage and faces the carburetor to attenuate the noise from the carburetor intake port.

Abstract: A workman's lift platform apparatus has a vertically swingable and extensible boom with a workman's platform at the outer end. A color coding indicating the amount of boom extension is provided on the fly section of the boom, visible to the workman in the platform, and an indicator plate having corresponding color coding is provided adjacent the controls on the platform. A Bowden cable is connected to the indicator plate and the fly section, to move the indicator plate proportionately to the angle of the boom to the horizontal.

Abstract: A portable stabbing board adapted to be attached to a rig for supporting a worker while stabbing joints of tubular members together during running operations including a frame member mountable with the rig, attachment members with the frame member for removably securing the frame member with the rig, a platform adapted for vertical movement along the frame member for supporting a worker during running operations, power means mounted with the platform for providing motive force for moving the platform vertically with respect to the frame member, and safety members with the platform and frame member for preventing unwanted vertical movement of the platform during such running operations.

Abstract: Automatic lubrication control system in which current flow between two mating electrically conductive, lubricated members in sliding contact is integrated with respect to time and used to provide a control signal for a pump that applies lubricant to the contact surface. The voltage level resulting from the integrated current flow can be applied directly to control the pump circuit or it can be counted or sampled at preselected times to provide the pump actuating signal.

Abstract: An automatic vehicle lubrication system is disclosed wherein the lubricant is directed successively and selectively to receiving stations, including means for automatically switching and directing the lubricant to successive stations receiving a predetermined quantity of lubricant.

Abstract: A lubricating collar for cable includes a truncated conically-shaped funnel section forming an entry guide terminating in an annular collar section that forms a lubricant discharge station which is openly exposed to the cable entry end of the collar. An internal chamber in the collar section supplies lubricant to orifices in the side wall thereof. Downstream of the lubricant discharge station there is a brush with a multitude of elongated fibrous bristles projecting radially from the side wall of the collar into the internal passageway of the collar to contact and spread lubricant on the outer surface of the cable when moved within the collar to a discharge guide section.

Abstract: The operation control section of an elevator system is constituted of two computers one of which shares the processing function with the other. One of the computers has a means for detecting an abnormality occurring in the other computer and stores therein a program for bringing the elevator cage to the nearest floor when the cage is stopped in an intermediate position between floors. If one of the computers falls in a fault, the cage is immediately stopped for assuring the safety of passengers. If the cage is stopped in the position between floors, the other computer causes the cage to be moved to the nearest floor for the rescue of the passengers.

Abstract: An anti-rusting structure of an adjust mechanism in a drum brake, which mechanism functions to compensate stroke increasing of the brake system due to wearing of the brake shoes, for preventing production of rust between an adjust bolt and an adjust nut by means of a skillful water proof device by facilitating the greasing between the two members of the adjust mechanism. In a portion of the adjust bolt where external thread (male screw) is formed, at least one lengthwise groove is axially formed, the length of which groove is determined such that the adjust bolt may not be pushed out by compressed air between the two members, even when the adjust bolt is threaded into the adjust nut by a predetermined amount of length, with sufficient grease being spread between the two members.

Abstract: An anti-spin brake energizer includes a friction member pivotally mounted adjacent a brake rotor. A solenoid urges the friction member into engagement with the rotor in response to a spinning wheel condition. The engaged friction member wedges between a piston and the rotor and wedges the piston away from the rotor. The movement of the piston away from the rotor generates a fluid pressure signal in a chamber communicated to the brake to retard the rotation of the rotor to thereby eliminate the spinning condition. A relief valve communicates the chamber with the master cylinder to terminate the fluid pressure signal in response to deactivation of the solenoid and to permit return of the friction member to its rest position spaced apart from the rotor.

Abstract: A device for automatically reducing excess play in moving parts of brakes comprises a stem moved axially from a rest position to an operative position.The stem can be threaded into a coupling lever such as to accommodate the drift of the rest position, to this end the stem being furthermore provided with a projecting arm imparting thereto a play compensating torque by engagement against an end-of-travel detent.

Abstract: The invention provides a protective shield device for a brake having a rotating braking element in the form of a ring or drum. The shield comprises a plate which extends opposite the face of at least a part of the rotating element of the brake, and a sheet part which extends the plate by running out from the plane of the latter to penetrate into the internal space of the rotating element in the immediate vicinity thereof. This provides an ejector for the brake which prevents solid particles such as grit entering the brake parts.The invention is particularly applicable to brakes designed for use in motor vehicles.

Abstract: A diaphragm clutch cover assembly is disclosed comprising a cover having a peripheral flange secured to a flywheel, a diaphragm spring, assembly means rockably mounting the diaphragm spring on the cover between axial spaced fulcra and axially applying a predetermined resilient clamping load, and a pressure plate fixed for rotation with and axial displacement in relation to the cover. The resilient clamping load on the diaphragm spring is selected between the peak value of the release load on the diaphragm spring at the minimum reference value and the greater of the final value of the release load at the minimum reference value and the final value of the release load at the maximum reference distance. In the coarse of service life the diaphragm spring breaks contact with one of its fulcra when it rocks from its engagement position and its disengagement position.

Abstract: A control function splitter for controlling a clutch and gearbox assembly and a throttle, particularly in marine applications. The splitter has main and override throttle shafts, and a clutch operating shaft connected to engine and assembly inputs. The splitter has a cam which moves axially to reflect control head signals. The cam has portions representing travel for gear engagement only with no throttle change, and travel between idle and full throttle with no gear change. A motion converting structure converts axial cam movement to limited clutch shaft rotation. An interlock between the clutch shaft and override throttle shaft prevents rotation of the clutch operating shaft unless both throttle shafts are at idle, and also prevents rotation of the override throttle shaft unless the clutch shaft is in neutral. The splitter reduces previous problems associated with non-lineality between a control head signal and the corresponding throttle output signal, and also improves positive "feel" of gear selection.

Abstract: A wrap-down spring clutch includes a drum and a spring which are selectively engaged by a solenoid. The solenoid has a coil, which when energized, extends a ferromagnetic plunger. When the coil is energized the plunger is extended out against the spring and urges the same into frictional engagement with the drum. The drum is also ferromagnetic, such that the activation of the coil simultaneously magnetizes the plunger, and creates a magnetic attraction between the plunger and the drum which further urges the plunger against the spring and the drum to produce a wrap-down pressure which effects quick and secure clutch engagement.

Abstract: A disc caliper clutch, including a rotor slidable along a spline of a shaft so as to frictionally engage with two plates between which the rotor is sandwiched; each of the plates being fitted with friction pads on its side and against which the rotor abuts, the pads being made easily replaceable, and one of the plates being additionally fitted with stop blocks so as to limit the amount of wear on the friction pads before requiring replacement and thus prevent damage to the rotor.

Abstract: A mechanical drive assembly includes driving and driven gear members with an internally splined coupling sleeve for engagement with said members. The sleeve includes a locking cam carried internally and being selectively actuable to move the sleeve between coupling-engaged and coupling-disengaged positions. The axis of rotation of the cam is offset from the central axis thereof whereby, when the cam is rotated through 180.degree. from the coupling-engaged position, the sleeve is moved forceably away from the driving member. Such movement of the sleeve is effected either by direct engagement of the cam face upon the driving gear member or by engagement of a cam follower on the driven gear member with a cam track.

Abstract: A clutch actuation system for a vehicle, comprises a first assembly adapted to be driven from a stop position by an actuating force, and a second assembly, which is driven by the first assembly, and drives in a certain direction a driven member which moves in such a way that a first part of its travel is accomplished against a relatively weak resisting force, and a following part of its travel is accomplished against a relatively strong restoring force. A clearance adjuster comprises means for biasing the first and second assemblies with respect to one another in such a direction as, if the first assembly remains in its stop position, to drive the driven member in said certain direction with biasing force strong enough to overcome said relatively weak resisting force but not strong enough to overcome said relatively strong restoring force, and means for locking the position of said first assembly with respect to said second assembly when said first assembly is moved off its stop position.