Abstract: An integral unit is provided comprising a raisable and tiltable door panel member and a frame structure therefor containing the driving mechanism. All the components of the driving mechanism are not only contained within the door frame member, but are also entirely concealed therewithin so that the integral unit has an agreeable and esthetic appearance, both from the front and from the rear side. Nobody can tamper with the driving mechanism, neither from its front nor from its rear side. No greased nor oiled components (such as chains, cables and the like) are exposed, with which the user may soil its clothes or its hands when passing by. The entire unit may be manufactured and its operation tested at the factory, and thereafter it can be assembled at the site of use by only fixing the frame in position in the corresponding wall aperture.

Abstract: An oven door stretch gasket which comprises an extruded length of silicone rubber having a relatively short hooked metal insert adhered to the interior of the ends thereof. The insert is adhered by means of room temperature vulcanizing silicone rubber cement. The hook ends are adapted to be engaged in apertures which are provided at the corners of an oven chamber in a stretching action, the openings being spaced apart somewhat more than the unstretched distance between the hook ends. To install or remove the gasket it must be stretched.The invention herein is concerned with a structure which will provide a more tenacious adherence between the insert and the length of gasket.

Abstract: A multiple track window, preferably with extruded plastic framing and glazing sealing strips, is described. Glazing panels are releaseably held and slideable for opening within side framing channels which are formed by releaseably interlocking members which may be integrally hinged to one another. The glazing panels are also directly removeable from the channels formed. Sealing strips with tubular protrusions are attached to adjacent edges of the glazing panels and provide a seal at their central meeting. Such a sealing strip is also adapted for use as a sill sealing strip. Thus, a tightly sealable and efficient insulating window formed from improved elements in accordance with the disclosure is provided. The glazing panels of the window may be opened to adapt to climactic conditions or ventilation requirements, or may be removed for cleaning, maintenance or other reason.

Abstract: An elongated metal workpiece such as a slab or billet is moved longitudinally beneath a grinding head by a reciprocating car mounted on an elongated track. The grinding head includes a rotating grinding wheel mounted at the end of a first arm which is pivotally secured to one end of a pivotally mounted second arm. A hydraulic actuator extending between the frame and the first arm controls the grinding force exerted by the grinding wheel on the workpiece. One end of the actuator is connected to an accumulator which provides a constant upward bias to the arm while the pressure in the other end of the actuator is varied in accordance with a pressure control signal. The pressure control signal is derived from both a calculated torque command indicative of the grinding force expected to produce a grinding torque corresponding to the torque command and a torque error signal which is a function of the deviation of actual torque from the torque command in order to maintain the grinding torque substantially constant.

Abstract: A precast concrete stairway module comprising a concrete wall assembly which is C-shaped in plan view, providing a side wall and two end walls, a concrete stair flight extending from an edge of one side wall to a mid-height position of the other side wall. The stair flight assembly is moulded integrally with the wall assembly and comprises a landing at each end and a flight of stairs therebetween. An access opening is provided in the wall assembly.

Abstract: A roof or wall structure incorporating support assemblies of this invention is disclosed. The roof or wall structure comprises an inner sheath secured to plural spaced-apart purlins or girts; an outer sheath; plural spaced-apart support means each assembled from a plurality of the present support means, secured to the inner sheath and to the outer sheath for maintaining the outer sheath spaced from the inner sheath; and thermal insulation filling the space between the inner and outer sheaths. The arrangement is such that the thermal insulation has a substantially uniform thickness throughout the roof or wall structure. The depth of the support means may be varied to accommodate the desired thickness of thermal insulation. The support means accommodate thermal expansion and contraction of the outer sheath independently of the inner sheath, thereby totally eliminating the possibility of leaks associated with prior art structures.

Abstract: A shutter assembly for use on an exterior wall surface at a window opening or the like, the shutter assembly consisting of a frame and a panel formed of an expanded metal sheet, the expanded metal sheet being provided with a plurality of air vent defining means. The side or jamb members of the frame and the upper and lower frame members are each provided with improved means to hold an expanded metal sheet of novel design within the frame so that it can withstand high loading imposed upon it as for example during a hurricane. In addition, an improved method of assembling the shutter is disclosed herein.

Abstract: This invention relates to a modular insulating article for insulating the interior of a high temperature furnace. The article comprises an outer shell-like form made of a ceramic fiber blanket, and interior layers made of ceramic fiber blanket material. The interior layers are disposed in planes which are parallel to the walls of the furnace. The layers are joined to each other and to the outer shell by means of an anchor pin and/or cement. The module is attached to the furnace wall by a mechanical anchor, preferably a "T" shaped stud, or refractory cement. The module has improved insulating value because of the disposition of the blankets and provides for the use of a high heat resistant blanket near the hot face and of lower cost high insulation blankets adjacent to the furnace wall.

Abstract: A centering for casting concrete roofs comprising a rectangular steel construction including at least two longitudinal girders (1, 2) and a plurality of spaced cross beams (3) welded thereto constituting a support of a flat form board for casting. According to the invention, each one of said cross beams (3) is provided, at least at one end of the centering, with an extension arm (9) which can be moved lengthwise of the cross beam to adjust the total width of said steel construction so that it may be adapted to meet the requirements of supporting form boards with varying widths (FIG. 1).

Abstract: A knock down tapered pole for a power-line wherein the pole is comprised of a series of superimposed pole sections with each section including a series of U-shaped bent-corner plates of uniform cross-sectional thickness and a plurality of trapezoidal-shaped flat plates positioned between the bent-corner plates and where the corner plates and the flat plates are secured together by means of fasteners.

Abstract: A trolley for aiding in the installation of sidewall panels to the eave struts and purlins of prefabricated metal buildings. The trolley has a seat support member with foot stirrups for carrying a workman and a pair of wheel carrying brackets secured to opposite sides of the support member. The wheels are carried on and roll over the horizontal portions of an eave strut and adjacent purlin. The support member and one of the brackets are adjustable for variations in the design dimensions of prefabricated buildings.

Abstract: Apparatus for filling containers with articles.A feed conveyor of slats having article receiving apertures is supplied with articles from a chute or a vibratory hopper. A tray below the slats prevents articles falling through until a discharge point is reached where the tray terminates, allowing articles to fall into a transverse line of hoppers below the conveyor.A gate prevents the articles from leaving the hoppers until a line of empty cans on a second transverse conveyor are in position therebelow.A stop across the end of the hopper prevents excess articles entering the feed conveyor.A rotary brush or roller clears any surplus articles from the feed conveyor.

Abstract: This invention essentially relates to a grid for guiding bottles advancing towards compartments of a packing case. The grid has vertically fastened thereto supports each including a sleeve containing axial-push means together with a rod cooperating therewith to resiliently maintain a group of short fingers while imparting to their free ends a spaced apart position under the action of the axial push.

Abstract: A grid set for use on an article loading machine for guiding cartons of articles such as drinks into a case carried therebelow. A plurality of guide arms are pivotally carried in a rectangular frame directly below a drop assembly for guiding the cartons of drinks into a cardboard case ensuring that the corners of the case are extended fully. Cam means cooperate with the guide arms for holding the cartons of drinks as the entire frame is lowered to the case for gently depositing the cartons of drinks into the case.

Abstract: This invention relates to a method for producing a composite container having a body label or tubular sleeve mounted thereon adapted to be shrunken onto exterior surface areas of a cylindrical container. The tubular sleeve is preformed of thin flexible thermoplastic material and may be flat-folded until ready for use when it is fully opened and conveyed in axial registry with the container inverted therebeneath. The sleeve preform of heat-shrinkable plastic material is telescopically assembled onto the inverted container while the latter is conveyed through a coincidental aligned path. The container preferably consists of a hollow glass or plastic container held invertedly by its neck portion with the tubular preform made slightly larger in diameter to surround the body and neck portions of the container. The tubular sleeve preform is held fully opened and is then transported downwardly in telescopic relation when in axial alignment with the inverted container.

Abstract: There is disclosed a machine for wrapping a skid-supported load with stretch wrap film. A roll of film is moved up and then down, at the same time that the turntable which carries the load to be wrapped rotates on its axis. The film is thus wound around the load in the form of a spiral. The machine is provided with dials for setting the skid height and the load height, so that the overall wrap is within limits set by the operator. The operator also sets a dial to control a predetermined number of extra wraps at the top of the load and at the bottom. Wherever reinforcement is required, the pressing of a "reinforce" button allows extra wraps to be formed. The tension in the film builds up from a minimum value to a maximum value during approximately the first half turn of the turntable; unlike the prior art, the maximum tension is not suddenly applied as the wrapping is in progress. The operator can also control the magnitude of this maximum tension.

Abstract: An apparatus for inserting a carton into a thermoplastic bag includes a table for supporting the bag, a pusher assembly for transferring a carton into the bag, and a guide assembly for first opening the bag mouth and for thereafter guiding the carton into the mouth of the bag while supporting the carton above the table until after it has been fully inserted into the bag. A vacuum is applied through apertures formed in the table to initially hold the bottom panel of the bag against the table, and a reciprocatable suction cup assembly is mounted above the suction apertures for engaging the top panel of the bag and for partially opening the mouth of the bag so that the guide assembly may be inserted therein.

Abstract: Aquatic harvesting apparatus employs a harvesting barge with vertical and horizontal weed cutters and a tunnel extending from the cutting throat through the entire length of the harvesting barge for discharge of the cut weeds into a collection container coupled to the stern. The cut vegetation is not elevated from the water during this procedure. The collection container is paneled with mesh and has a gate which can be opened to receive the weeds and closed to seal the container. The container can be towed to shore or elevated by a crane.

Abstract: An adjustable axle support system for a lawn mower for supporting the whe and blade housing at a preselectable elevation in accordance with a desired cutting height of the grass cutting blade which is rotatable in a horizontal plane within the blade housing of the mower. The system includes brackets fixed to the opposite ends of the front and rear sections of the blade housing with the axles received in vertical slots formed in the brackets. Axle bearings are slidable on the axles for receipt in enlarged openings formed along the slots in the brackets. The axle bearings are biased into the selected enlarged openings by coil compression springs received about the axles. Adjustment of the height of the blade housing and in turn the cutting blade is achieved simply by retracting the bearings along the axles against the bias of the springs and moving the axles along the slots in the brackets into the desired elevation and then placing the bearings into the appropriate enlarged openings along the bracket slots.

Abstract: An optical cable is assembled by laying up optical fibres around the surface of a central strength filament. To minimize longitudinal tension in the fibres, air is directed along the surface of the cable in a feed direction. A blow-pipe type device has a pair of concentric tubes along the central longitudinal axis of which cable is drawn. The tubes are sealed together at the upstream end, the outer tube extending beyond the inner tube at the downstream end. Compressed air injected between the tubes is directed along the cable surface as it escapes from the downstream end. The air jet both frictionally urges fibres in the feed direction and creates a partial vacuum over the fibres to locally reduce contact pressure between the fibres and the central strength filament.

Abstract: A bulky continuous filament yarn, in which continuous filament core yarns of polymeric material are substantially straight and free from loops and comprise from about 65 to about 93 percent of the total filaments by weight while the remainder of the total filaments are continuous filament effect yarns having a denier per filament of up to 5.0 that are inserted between the filaments of the core yarn and protrude from the surface of the core yarn in a mixture of crunodal and arch-like loops, is made by feeding a larger denier yarn at low overfeed and a much smaller denier yarn at low to moderate overfeed through a jet supplied with ambient air.

Abstract: During servicing of a spinning machine station by the piecing apparatus, the yarn positioning means establishes a generally U-shaped yarn line and brings the lowermost bight section of such line into desired association with the yarn delivery rolls at the spinning machine station. Rotatable members form the bight section of the yarn line and then transport the same, while the members occupy rotative positions effective to prevent lateral movement of the bight section, to a location closely adjacent the delivery rolls. The members then are rotated to other positions wherein they permit and guide lateral movement of the bight section toward a free end of one of the delivery rolls. When a piecing-aid device is present at the spinning machine station, the piecing apparatus includes a mechanism for imparting movement to a movable component of the device, and the positioning means of the apparatus includes means for associating parts of the U-shaped yarn line with the foregoing and other components of the device.

Abstract: False twisting method and apparatus of nipping type for producing crimped filament yarns, comprising two flat endless belts supported, under tension, on two pairs of pulleys, respectively, so as to run in different directions relative to each other and having work surfaces of a relatively small friction coefficient and straightly extending regions defined between their mating supporting pulleys and crossing each other at a selected angle to provide a crossing zone, while being urged, with a desired pressure of contact, against each other at this crossing zone for positively nipping thereat a filament yarn to thereby twist this filament yarn, while urging this filament yarn to advance progressively from the crossing zone.

Abstract: A regenerative, parallel-compound, dual-fluid heat engine is set forth wherein important engine parameters are specified and linked to each other in a manner which maximizes engine efficiency and throughput for an engine of this type.

Abstract: An improved integrated control system for a gas turbine engine includes fuel control means for metering the flow of fuel to the engine in accordance with a fuel control position signal. A primary control means generates a primary fuel control position signal. A back-up control means generates a back-up fuel control position signal as a function of the actual engine speed in a primary mode and as a function of the power lever angle in a back-up mode. Transfer means is included to receive both the primary and back-up fuel control position signals and to provide only the primary signal to the fuel control means when the system in the primary mode and to provide only the back-up signal to the fuel control means when the system is in the back-up mode.

Abstract: A V.S.T.O.L. gas turbine power plant includes a main gas turbine engine having an exhaust gas propulsion nozzle and a fan arranged within a fan duct, which duct terminates in two nozzles such that a portion of the fan air may be directed vertically downwards or horizontally, the remaining portion of the fan air acts as a working fluid in one or more further auxiliary gas turbine engines each engine including a vectorable exhaust nozzle.

Abstract: A control system and method for utilizing the rotational speed of the high-speed spool in a multi-spool turbofan engine to stabilize changes in engine operation which affect the thrust output of the engine. Signals representing the actual rotational speed of the high-speed spool, the actual value of the selected engine pressures which provide an accurate measure of engine thrust, and a commanded value of the selected engine pressures are processed; and an error signal is provided in response to these three signals which is a function of all three signals. The error signal is then used to control the rate of fuel flow to the engine which, in turn, controls engine thrust. In one embodiment the error signal is a function of the rotational speed of the high-speed spool and the actual and commanded values of engine pressure ratio, and in another embodiment the error signal is a function of the rotational speed of the high-speed spool and the actual and commanded values of integrated engine pressure ratio.

Abstract: Disclosed is apparatus for storing energy and generating electricity. The apparatus comprises (1) first means (10) for storing energy in the form of compressed gas and (2) second means (12) for generating electricity by allowing the gas compressed by the first means to expand, doing useful work.

Abstract: This invention relates to a tuneable spring/mass dynamic energy absorber with air pumps connected so that the floats become essentially stationary while energy is absorbed at a high rate. The system has a large mass ratio (water mass/float mass) and low float buoyancy rate which combine to preclude float resonances above and below the absorber frequency.

Abstract: Drive is transmitted from a cam to a push rod via a body of liquid trapped between two pistons. A control element is normally urged against a seat by pressure in the body of liquid but can be lifted off its seat by the application of pressure to liquid in a control chamber. When the control element moves clear of its seat, liquid trapped between the pistons acts on a seat-engaging face of the control element and displaces the control element instead of driving the push rod.

Abstract: A vent accumulator for a hydraulic integrator of the type having at least three pistons arranged in end-to-end relationship within an elongated housing. Each piston is adapted to move under hydraulic pressure in a direction away from one longitudinal end of the housing towards the opposite longitudinal end. Each of the pistons, except for the last piston adjacent the opposite end of the housing, is provided with a piston rod operatively connected to the piston next adjacent towards one end of the housing. Each piston is defined as having a first side directed towards one end of the housing and a second side directed towards the opposite end of the housing. Each of the pistons, except for the last two pistons in line, is provided with means for receiving hydraulic fluid under pressure from a load cell on its first side and an air vent communicates on it second side.

Abstract: An exhaust bypass valve assembly for an internal combustion engine including a throttle valve downstream of a compressor of an exhaust gas turbo-supercharger for controlling intake mixture flows, a bypass causing part of exhaust gases to flow therethrough without passing through an exhaust gas turbine and an exhaust bypass valve provided in said bypass comprises a first diaphragm device adapted to be operated by a pressure upstream of the throttle valve to open the exhaust bypass valve and a second diaphragm device adapted to be operated by a pressure difference across the throttle valve to open the exhaust bypass valve. The first and second diaphragm devices are arranged in series with a rod of the exhaust bypass valve. With this arrangement according to the invention, the bypass valve is opened by the difference pressure across the throttle valve during an operation of an engine under a partially loaded condition, thereby rendering smooth the exhaust gas flow to improve the combustion of fuel mixture.

Abstract: A system of operating an engine on a recyclable, relatively non-polluting fuel. The fuel may include any one or more of the following: magnesium (Mg), aluminum (Al), magnesium plus aluminum, magnesium-aluminum alloy, magnesium hydride (MgH.sub.2) aluminum hydride (AlH.sub.3) and magnesium aluminum hydride (Mg(AlH.sub.4).sub.2). The fuel when burned produces oxides and hydroxides of magnesium and/or aluminum. The oxides and hydroxides can be reduced to magnesium and/or aluminum and/or their hydrides and reformed for reuse in the engine. The system is intended for use not only in automotive engines but also stationary power plants including refrigeration.

Abstract: A temperature conditioning system employing an ejector-type compressor and a refrigerant selected for operation at the limited operating temperatures of a heat energy collection and storage apparatus. Improved performance may be achieved by employing a two-tank storage system having a control circuit for supplying heat transfer medium from the hotter of the tanks for return to the cooler.

Abstract: A double-yoke balanced compressor for a cryogenic cooler that has only lir motion imparted to balanced piston and cylinder masses. A piston yoke is driven in the linear stroke direction by a piston axially offset crankshaft cam and a cylinder yoke is driven linearly by a cylinder axially offset crankshaft cam that is exactly offset 180.degree. from the other cam. A large circular bushing in the compressor housing covers the entire outer cylinder head during linear operation to prevent blow by and to guide the cylinder linearly. The lower portion of the piston and cylinder connecting rods fit into linear guides that are further comprised of low molecular weight gas filled cavities to provide additional air bearing smoothness to the linear motion of the piston and cylinder.

Abstract: A system and method for controlling a refrigeration unit of an air conditioning system operating in connection with a given building environment so as to establish conditions providing a desired comfort level within the building environment, the system and method being arranged to detect the output of the refrigeration unit, to detect changes in interior or exterior conditions which will affect the comfort level in the building environment and to provide at least one control signal in response to the detected output and conditions for operating the refrigeration unit, the control signal being compensated for the predetermined dynamic characteristics of the particular refrigeration unit and the predetermined dynamic characteristics of the particular building environment such that the control signal will anticipate further change in the conditions within the building environment and will operate the refrigeration unit so as to counter the anticipated further change and tend to maintain the desired comfort level

Abstract: A sensor for detecting changes in the rate of flow of a gaseous stream by sensing changes of temperature up and down stream of a single heat source. The invention finds application as a frost sensor for use in a defrost system.

Abstract: In the main intended application of the arrangement according to the invention, that is, using a reversible motor compressor in a heat pump in a refrigerating or air conditioning system, it is desirable to insure a delay during reversal of the direction of compressor operation. A control arrangement is provided in which the control system controls the direction of motor operation or compressor capacity in accordance with temperature conditions, the system including control means for effecting operation in a low capacity direction or condition, or alternatively in a high capacity direction or condition in response to one set, and another set, respectively, of temperature conditions and with timer means delaying a restart of the compressor motor for at least a predetermined time in response to a condition of the control means operative to initiate a change in the operating direction or condition of the compressor when it restarts.

Abstract: An improved load balancing control circuit for at least three electric motor-driven centrifugal refrigerant compressors comprises a current transformer secondary 90', 91', 92' and a respective load resistor 93', 95', 97' in series to form the legs of a circuit in which the legs are connected in a delta, each leg having a shorting switch 110', 111', 112' connected across it, and a balancing resistance network including balancing resistors 94', 96', 98' are connected in a wye circuit with the delta circuit.

Abstract: A control system and a method are disclosed for automatically controlling a hot gas bypass valve as a function for cooling load and head. A valve/controller is provided for controlling the operation of the hot gas bypass valve so as to avoid surging of the compressor in response to temperatures of the chilled liquid entering the evaporator, the chilled liquid leaving the evaporator, and the liquid refrigerant at the outlet of the condenser.

Abstract: This invention relates to a heat reclaiming device for a heat pump. The heat reclaimer is able to absorb heat from the compressor by circulating cooling fluid through a circuit which is mounted in good heat transfer relationship with the condenser, then around the shell of the motor-compressor and lastly around the hollow tube which connects the condenser to the compressor. The reclaiming circuit is connected into a fluid circulating loop which is used to supply heat to the evaporator coil of the heat pump.

Abstract: An air conditioner of heat pump type including a pair of indoor and outdoor heat exchangers, and a propeller fan interposed therebetween. The both heat exchangers and the propeller fan are mounted on a bottomplate member which also serves as a receptacle for a condensate. A slinger ring is disposed around the propeller fan for throwing the condensate toward the outdoor exchanger. Below the fan, the bottomplate member is formed with a drain port, which is positioned in a region which is free from a pool of water formed under the pneumatic pressure of the fan.

Abstract: A differential piston type reversing valve construction having a housing body provided with a high pressure chamber that has a valve member slideable therein for selectively interconnecting said high pressure chamber to either port of a pair of ports interrupting a valve seat of the housing body while interconnecting a low pressure port of the valve seat to the other port of the pair of ports, the valve member having a small piston member and a large piston member interconnected thereto and being disposed spaced from each other to define an intermediate chamber therebetween. The small piston member has one side thereof exposed to the high pressure chamber and the large piston member has one side thereof exposed to a control chamber of the housing body.

Abstract: Reversible-cycle closed-circuit refrigeration systems such as used in air conditioning units generally include first and second heat exchangers for transferring heat between a refrigerant and first and second fluids respectively, the systems being operative to transfer heat from the first fluid to the second and from the second fluid to the first via the refrigerant. The necessary work input is provided by a compressor. To enable the first and second heat exchangers to operate at maximum efficiency during heat transfer between the fluids in both directions, a further heat exchanger is provided which is operative only during heat transfer in one direction. This further exchanger compensates for the imbalance in heat flows in the two directions due to the heat of compression.

Abstract: A vertically elongated upright and closed bottom cabinet is provided including peripherally extending sides. A vertically extending passage structure is disposed within the cabinet inwardly of the peripheral sides thereof and the passage structure is constructed from material having good heat transfer properties and include upper and lower ends opening outwardly of the cabinet. Blower structure is operatively associated with the passage structure for pumping air through the passage structure and inlet structure is provided for admitting CO.sub.2 "snow" into the upper end portion of the cabinet about the passage structure for gravity falling of the "snow" within the cabinet toward the closed bottom thereof about the passage structure.

Abstract: A thermostatically and hygrostatically controlled cabinet for storing foodstuffs has a food storage chamber partially surrounded by an elongated space communicating with the food storage chamber through a grid. A fan establishes forced air circulation inside the elongated space, through the grid and inside the food storage chamber. An evaporator and a provision of water are located inside the elongated space and a compressor and a condenser are positioned outside the elongated space and the storage chamber. Thermostatic control means start the compressor when the temperature inside the food storage chamber exceeds a rated value and, after a time delay, also start the fan.

Abstract: A composite drive shaft having a hollow tubular, multi-layered fiber reinforced plastic shaft portion (11) with a metallic sleeve (13) inserted in and bonded thereto at least at one end, said sleeve (13) having universal joint connector means (12).

Abstract: A manual knitting frame having a pair of support blocks at opposite ends of two or more spaced longitudinally elongated members. Pegs projecting from each of the members. Rods connecting the blocks and passing through the members, one of which is threaded such that the spacing between the members can be adjusted. According to another form, the adjustment of the members is accomplished by screws attaching the members to a support at each end thereof.

Abstract: An elastic warp knit fabric having ravel resistant features made of a number of base yarns which are knitted to form a plurality of closed loops extending in a warp direction to form wales including interior wales, an end wale and an adjacent wale adjacent to the end wale. Elastic yarns are laid into the adjacent wale and interior wales. Filler yarns are included which extend in a weft direction and which are laid into the closed loops of each course. A locking yarn to prevent unraveling of the end wale is knitted into the end wale to form open loops in alternate courses and knitted into the adjacent wale to form closed loops in alternate courses.The end wale may have the elastic yarn eliminated therefrom in order to form a soft edge of the fabric in which event the adjacent wale then has a further elastic yarn to compensate for the elastic yarn removed from the end wale.

Abstract: Wide variations of the knitting program determined by the program drum of a circular knitting machine may be achieved by providing a plurality of rotatable program discs having peripheral seats for removable pins for determining supplementary programs and by providing followers co-operable with the program discs and linked to the means for advancing the program drum to selectively render the advancing means inoperative in dependence on the supplementary program. A driving linkage actuated by a cam track on the program drum is provided to allow relatively large angular advancement of the program drum when desired. Another driving linkage actuated by another cam track on the program drum is provided for reducing the speed of the needle cylinder.