Abstract: Control apparatus for a drive transmission such as the hydraulic drive transmission of a fork lift truck is provided in which an electrical signal is developed having a frequency representative of the rate of rotation of the drive shaft of the transmission. A first switching circuit is controlled in response to the said signal so as to remain in one state thereof during each cycle of the said signal when the duration of the cycle is less than a predetermined duration, and to be settable in another state thereof by actuation of a manually operable direction switch, serving as a forward-reverse drive selector lever, when the duration of the said cycle is greater than the said predetermined duration.

Abstract: A machine for the mechanical working of band saws is provided whose frame carries an appliance for gripping the saw on the sides, a mechanism for the pitch feed of the saw, tooth-setting tools secured on the ends of the arms which are kinematically linked with the machine drive, and a pair of knives for cutting off the saw blade. The knives are located after the tooth-setting tools in the direction of pitch feed. One of these knives is secured on the saw-gripping appliance, while the other one is kinematically linked with one of the arms carrying the tooth-setting tool for joint movement with the latter. The machine provides for manufacturing saws with any required number of teeth.

Abstract: A torque wrench having a main body of fixed overall length and having a torque adjusting mechanism enclosed within the main body. The adjusting mechanism is controlled by a rotatable handle disposed about the main body. The adjusting mechanism includes a first part which is connected with the handle for joint rotation therewith, but which is constrained against axial movement. The adjusting mechanism further includes a second part having a polygonal portion extending into a polygonal recess in the first part to couple the first and second parts for joint rotation while permitting linear movement of the second part. The second part is designed to move linearly in response to joint rotation of the first and second parts in order to effect adjustment of the torque setting of the wrench. The handle contains a locking mechanism to prevent movement of the adjusting mechanism during operation of the torque wrench.

Abstract: A mechanism for loading and/or unloading automatic lathes. A feed device having a transport means is provided for feeding a workpiece to a transfer station. The feed device is associated with a pivotable carrier member and includes means for gripping the workpiece.

Abstract: A punch retainer is formed with a bore in its upper portion for releasably securing a punch therein. The lower portion of the punch retainer is formed as a cylinder for a vertically movable stripper piston. The portion of the cylinder above the piston is connected to a source of gas under pressure so as to bias the piston downwardly. The punch extends downwardly in sealed relation through a central bore in the piston and terminates slightly above the lower end of the piston when the piston is in its lowermost position.

Abstract: A base frame mounts a first gang of saws in a common vertical datum plane and a first wood member conveyor device. A second gang of saws in a common vertical datum plane and a second wood member conveyor device are mounted on a carriage on the base frame for movement toward and away from the first gang of saws and first conveyor device. Each saw in each gang is independently vertically adjustable in its vertical datum plane and each saw is rotatable a full 180 degrees around the axis of a chord on the saw blade lying in the common datum plane of such saw. Each saw, during its angular rotation, is precisely supported on a double pantograph movement linkage which follows an arcuate track centered on said chord and vertical datum plane. A precision drive for the wood member conveyor devices and carriage obviates the necessity for a long torque shaft and enables much greater versatility of operation of the apparatus.

Abstract: There is disclosed herein a music synthesizer which responds to a music note played by a music instrument. The synthesizer has an envelope generator which generates a control signal in relation to the input signal to control the loudness of the synthesized note. Also, the synthesizer has a pair of voltage controlled oscillators, one of which provides a signal having a frequency related to the frequency of the input note, and the other of which provides a signal having a frequency related to the frequency of the input signal offset by the ratio of the difference between a programmed note and a referenced note, such as A440. The programmed note is that note following the operation of a control switch. The synthesizer further includes a series of footpads which control various functions of the synthesizer, such as programming the programmed note, to allow the user to control the synthesized sound while playing an instrument.

Abstract: An improved end pin for the violoncello and the string bass which comprises a receiving member having an outer nonslip support surface with an arcuate portion adapted to contact floor. The receiving member includes a cavity for receiving the existing end pin of a violoncello or string bass, in the case of retrofit applications, or a rod projecting out for replacement of existing pins. Means are provided for securely locking an existing end pin into the cavity of the receiving member. A yoke member is pivotally mounted to the receiving member for arcuate movement about the support surface and includes an opening therethrough for adjustably receiving a pin means. An adjustable pin means having a first pointed end extending from the yoke mounting to contact a surface for supporting said violoncello or string bass and a second end extending from the yoke to the outer support surface of the receiving member for adjustably securing said yoke relative to the receiving member.

Abstract: A feature of this invention is the provision for a Gatling type gun of a gun bolt of the oscillating head type having a gun bolt carriage with substantially radially projecting slides and a head with substantially radially projecting locking lugs, wherein the length of the radial projection of the slides is significantly greater than the length of the radial projection of the locking lugs.

Abstract: A lightweight armored vehicle and method of making the same is shown. The interior or a standard automobile to be equipped with lightweight armor is first stripped of its interior furnishings. Mechanisms to raise or lower the windows are removed. Doors and window frames are rebuilt to rigidly mount a bulletproof transparent window therein. Vertical walls of the automobile are bulletproofed by adding lightweight woven polyglass rigidly formed with a resin-catalyst mixture. Additional bullet resistant strength may be provided by multiple layers of ballistic nylon or Kevlar bonded to the rigid polyglass. For surfaces not normally subject to perpendicular penetration by bullets, only ballistic nylon or Kevlar is inserted. Upon reassembly of the automobile, including rebuilding portions of the exterior body around the doors and windows, options such as a tear gas dispersal system can be added. A steel screen between layers of the woven polyglass adds additional bullet resistant strength.

Abstract: In one form a greenhouse or solarium is provided in which the glazing is spaced from its supporting structure by channels employed along the end edges and top edge of the greenhouse or solarium structure. The spacing is effected by the use of channels which extend entirely along the end edges to obturate the space between the end edges and the supporting structure. Additional channels are provided in parallel with each other at spaced positions along the top edge of the glazing in order to connect the same to the supporting structure and space the top edge from the supporting structure. This develops an opening adjacent the top edge of the glazing which is covered by a shed mounted on the supporting structure. Suitably positioned fans are used to exhaust air from the enclosure formed by the glazing and a flap closing is provided for the opening adjacent the top edge in order to selectively obturate the same. A roll down cover is provided whereby selective covering of the glazing is enabled.

Abstract: A flow-distributing device comprises a perforated plate (1) which forms a defining wall of a passage or chamber arranged to accommodate a flow of fluid and provided with at least one further defining wall. Deflecting means (1a; 3) extend into the path of said flow adjacent the perforations (2) which are evenly distributed over at least a part of said wall. The deflecting means divide the flow into a plurality of part-flows which pass in mutually the same direction to the other side of the plate via the perforations. The deflecting means may comprise separate nozzles (3) or lips (1a) which have been pressed out of the material when forming the holes. The flow-distributing device may be incorporated in an air-supply device for a furnace, a fluidized bed, an air cooler or heater or the like. In one important application it is used in a substantially box-shaped air-intake screen (10) having a perforated side surface (10b) and an air-supply pipe (11).

Abstract: A jet pair weir gate is provided in an air diffuser outlet and includes two pairs of nested jet weir members, each member having a generally U-shaped channel configuration consisting of an imperforate web portion and two flange portions. Each pair of members in both laterally expansible and laterally moveable across the outlet width to cooperate with each other in providing selectable air flow patterns through the outlet. In a prefered embodiment, the medial flange of each pair of jet weir members is provided with an extended length serving as a control surface, each adjacent flanges together acting as an air nozzle to focus a jet flow of air therebetween.

Abstract: Apparatus for regulating air flow through a housing is disclosed. A damper assembly including a bowed leaf spring is provided such that the leaf spring contacts the edge of the damper to secure the damper in position. The combination arrangement is utilized to either regulate the flow of air being discharged from the unit or to divert air between multiple outlets in the housing.

Abstract: A closed pressurized container for producing a carbonated beverage of superior quality by providing for contact therein of water and a solid carbonation source. The pressurized container is designed to withstand the pressures and temperatures generated during the preparation of a carbonated beverage from a solid carbonation source. In a preferred embodiment, the container is a rigid receptacle in the shape of a wide mouth bottle adapted to receive a large cap or cover. A perforated basket is mounted inside the cover, and is accessible to water in the bottle when that vessel is turned upside down to an inverted position. A spring loaded, manually operated valve is provided in the cover to permit venting of carbon dioxide from the interior thereof after the water-based mixture within the container has become sufficiently carbonated by absorbing carbon dioxide released by contact of water with the solid carbonation source.

Abstract: A compact can crusher in which used beverage cans and the like are dropped into a chute and are crushed flat between an oscillating crusher plate and a wall of the chute, the crushed cans being dropped through an open lower end of the chute. A drive motor is coupled to the crusher plate to apply maximum thrust at opposite ends of the oscillating stroke, so that cans are effectively flattened to a minimum thickness. In one form spring stored energy adds to the initial crushing action when the most pressure is needed, and provision is made to prevent cans from jamming in the chute and to prevent the mechanism from being jammed by articles which are not readily crushed.

Abstract: A continuous press is disclosed for simultaneously pressing and conveying a workpiece, such as the laminations for making plywood, through the press in a continuous manner. The press comprises opposed sets of presser-conveyor rails which are spaced apart to receive a workpiece therebetween. The rails are mounted upon hydraulic actuators, one set of actuators for transverse motion of the rails and another set of actuators for longitudinal actuation of the rails. Each set of rails drives a separate caterpillar belt and the workpiece is interposed between the belts. The hydraulic actuators are energized in a sequence so that the rails maintain continuous pressing action through the belts and the belts maintain continuous conveyor action.

Abstract: A low voltage, electrically actuated, nonprimary explosive detonator is disclosed wherein said detonation is achieved by means of an explosive train in which a deflagration-to-detonation transition is made to occur. The explosive train is confined within a cylindrical body and positioned adjacent to low voltage ignition means have electrical leads extending outwardly from the cylindrical confining body. Application of a low voltage current to the electrical leads ignites a self-sustained deflagration in a donor portion of the explosive train which then is made to undergo a transition to detonation further down the train.

Abstract: Generator for generating electrical ignition or detonation energy in a spin projectile through a piezo element utilizing the spin of the projectile for generating the electrical energy. The piezo element lies against the interior of the projectile shell and is polarized radially relative to the longitudinal axis of the projectile. Preferably, the piezo element is of tubular configuration. A core is radially movably supported interiorly of the projectile shell so as to charge the piezo element during the rotational acceleration of the projectile.

Abstract: A fuze apparatus arms itself in flight and is especially adapted for use in training shells. The fuze has a casing with ignitable or explosive material located therein and an igniter mounted to ignite the ignitable material upon a sufficient impact against the igniter. The fuze is armed in flight by a movable cup moving against the spring bias which moves relative to the fuze casing by inertial force during acceleration, which allows an arming member to slide or roll between the sliding cup and the igniter where it is held until sufficient impact generated by inertial force from a larger mass is directed against the cup, driving the arming member against the igniter.

Abstract: The disclosed invention is an effective detonating cord which does not ignite combustible materials adjacent and exterior to the cord upon detonation. The cord in one of its broadest aspects comprises a core of high explosive coated with a composition extrudable around the core at safe temperatures and comprising a halogenated linear polymer with sufficient halogenation to prevent ignition of combustible materials adjacent and exterior to the cord upon detonation. The core preferably contains pentaerythritol tetranitrate and the preferred polymer is substantially amorphous chlorinated polyethylene (CPE) having about 25 to 50 weight percent chlorine. The coating composition frequently also includes synergistic agents known in the flame retardant arts such as antimony trioxide which enhance the flash-suppressing qualities of the coating, plasticizers such as polyethylene polymers and other materials such as extrusion aids.

Abstract: A track renewal train includes a vehicle bridging an intermediate right of way section between an old and a new track section, and this vehicle carries rail spreaders as well as equipment arranged in succession for removing the ties of the old track section, for lowering the level of, and planing, the ballast in the intermediate right of way section and for laying the ties of the new track section. The ballast lowering and placing equipment includes a ballast planing shield mounted on the vehicle and having a width at least equal to the length of the ties of the new track section, a ballast conveyor elevator associated with the ballast planing shield, the elevator extending over the width of the shield and having an input end adjacent the front end of the shield and an output end at the trailing end of the shield, and a ballast dumping conveyor arranged to receive ballast from the output end of the elevator.

Abstract: A railway car truck having side frames with an opening for receiving the ends of a bolster, and spaced columns with removable wear resistant wear plates, secured thereto and retained by L-shaped retainers at the corners.

Abstract: An air control system is provided for a vehicle convertible between highway and railway modes of travel. A main body on the vehicles includes a highway wheel-set axle unit and a rail wheel-set axle unit. The vehicle is designed so that one wheel-set axle unit is stored in an upper position while the other is in the lowered operative position. During a transfer from the highway mode of travel to the railroad mode of travel, or vice-versa, an air control system selectively allows the wheel-set axle units to be positioned in either the raised or lowered position dependent upon the mode of travel to be used. Rail suspension air springs are connected between the main body of the vehicle and the rail wheel-set axle unit and highway suspension air springs are connected between the body and the highway wheel-set axle units.

Abstract: A plastic pallet provided with oblong channels in which reinforcing rods are locked. The locking is obtained by partially closing the end of a channel or by inwardly shrunk edge parts of openings in said channels.

Abstract: Furnace performance is controlled during start-up or very low load operation at a time when the minimum air flow required to be supplied to the furnace is significantly greater than that required to burn the fuel being supplied to the furnace. Decreased furnace heat absorption is accomplished by supplying a larger quantity of the air immediately adjacent the fuel input location for the purpose of diluting the combustion gases and immediately decreasing their temperature level. Increased furnace heat absorption is obtained by introducing a greater portion of the air flow into the furnace at a location remote from the fuel being burned so that the gases at the fuel location remain at a high temperature, and transfer heat to the walls, before being diluted by the incoming air.

Abstract: A throat plate having means attached thereto for preventing the work limb in a loop of thread from being drawn up through the material being sewn by the take-up limb due to friction therebetween causing a loose stitch known as a halo.

Abstract: A combined sewing machine housing and a clamping jig therefor to position the housing for machining purposes comprises a housing bed arm having a column connected to one end and extending upwardly therefrom and supporting one end of an upper arm. The clamping jig includes a post having stop guards thereon for aligning the upper arm and bed arms and column so that they may be positioned on the top of the jig. The sewing machine housing also has a plurality of bearing surfaces defined thereon which may be aligned with or engaged over a corresponding number of clamping elements in the form of rotatable dogs. When the housing is in position on the clamping jig it will be aligned so that one clamping dog enters through an opening of the sewing machine housing and may be rotated into a position to clamp against a bearing surface and the other clamping dogs may be rotated to engage over a bearing surface which is positioned alongside of it.

Abstract: A method for making the top panel and border of a hybrid waterbed mattress is described herein which includes sewing a top panel together with a flanging material along first and second parallel lines, sewing the top half of a zipper to the top panel and flanging material along third and fourth lines, the third line being spaced between the first and second lines and the fourth line being about along the first line, sewing the bottom half of the zipper to the side panel of the mattress and sewing a tape over the edges of the top panel, flanging material and top half of the zipper along a fifth line parallel with and intermediate the first and second lines.

Abstract: A wind propelled craft adapted for movement over water or ice having an equilateral tetrahedral frame comprising three substantially equidistantly spaced support members adapted to engage and be supported on the surface of the water, four substantially rigid spars connected together at a juncture and extending radially outward therefrom such that they are separated from each other by equal angles, and a plurality of equilength stays connected between each of the spars and the other spars at points on the spars substantially equidistant from the juncture so as to form with the spars a frame of substantially equilateral tetrahedral shape. Three of the spars extend laterally and downwardly from the juncture and are connected to the support members by stays with the fourth spar extending upwardly from the juncture. A pair of triangular mainsails are connected to respective pairs of stays extending downwardly from the vertical spar in such a manner that they are capable of being raised and lowered.

Abstract: A lifting keel assembly for sailboats having a shaft obliquely inclined in forward and upward directions slidably receiving the lifting keel, the upper area of the lifting keel being provided with sliding shoes on the forward and rearward longitudinal edges, which sliding shoes are guided in associated prismatic guides of the shaft, one sliding shoe having on either side a protruding V-profile, and the associated guide enclosing said two V-profiles of the sliding shoe, while a further sliding shoe on the other edge of the keel is guided in an associated guide by two oppositely arranged sliding surfaces.

Abstract: Structure for berthing marine craft, yachts and the like, comprises longitudinal beams supporting transverse boards for walking on. A retaining strip of L-shaped cross section covers the end edges of the boards and is secured to the beams by nut and bolt assemblies that pass through the beams and retaining strips and serve as distance pieces between adjacent boards. A wooden wale is also bordered along its upper edge by the downwardly depending flange of the retaining strip. Central portions of the boards are pressed upwardly against the restraining influence of the retaining strips, to maintain the boards regular under all conditions, and also to strengthen the boards by prestressing them.

Abstract: A depletion indicating mechanism allows for visual inspection of the quantity of components contained in a storage bin. The storage bin is mounted on a fixed frame structure, such as a wall, and the bin is held in a tilted position in opposition to the gravitational force acting on the bin. A mechanism is responsive to the change of weight of the bin as the quantity of components is reduced so that angular displacement of the bin occurs. The mechanism amplifies the angular displacement of the bin into corresponding depletion measurements on a mechanical gauge which allows for visual inspection of an indicator to quickly determine the degree of bin depletion.

Abstract: A single facer is provided with an adjustable width glue means including an elongated floating shoe having doctor blade means biased toward a glue applicator roll and movable away from the latter to form a metering gap through which glue exits from an elongated fluid cavity of the shoe as a thin film on the applicator roll. The shoe also includes an elongated fluid manifold which receives glue under pressure from a glue supply. A plurality of passages formed in the shoe and spaced along the length thereof interconnect the fluid cavity and manifold so that glue flows to the former from the latter. Longitudinally adjustable side dams are provided for the cavity and manifold to control the width of the glue film. A cleaning fluid introduced at the ends of the manifold flushes through those passages outboard of the dams and exits at the ends of the cavity to prevent build-up of glue in the shoe.

Abstract: A vapor phase deposition apparatus includes a coaxially mounted reactor tube, jacketed assembly tube, bearing/plug assembly, and rod/substrate holder. Gas inlets are provided in the reactor tube, and assembly tube and a vent is provided on the jacketed portion of the assembly tube, such that a double counterflow gas pattern can be established in the apparatus. The apparatus permits controllable deposition cycle and it can be readily disassembled for periodic maintenance.

Abstract: The invention relates to an artificial fish-gathering reef constructed with square bar materials and plate materials, the plate materials are alternately piled on the bar materials in a manner to provide open rooms for fish-swimming space.

Abstract: A dung removal conveyor (18, 20) for multi-deck poultry battery-nest installations with dropping plates arranged under the roost grates, including a single chain (12) centrally connected to scraper crosspieces (14) so as to allow limited movement therebetween, an oil pan (22), and oscillating plunger apparatus (27) for dipping into the oil pan and then extending to a position where oil carried thereby falls to lubricate the conveyor.

Abstract: An animal bathing stand adapted to be disposed within wash basins or the like to aid in the washing of an animal. The stand preferably comprises a generally planar, rigid central surface elevated from the bottom of the wash basin by foot structure which may be varied in length to fit the individual application. A resilient pad disposed over the supporting surface provides secure footing for the animal to be washed. The pad preferably includes a peripheral skirt for adapting the stand for use in wash basins of varying dimensions. Perforations provided within the skirt aid in draining. Leash structure provided in a preferred form of the washing stand may be variably coupled between the supporting stand and the animal to facilitate use of the invention with animals of different height.

Abstract: Method and apparatus for improving convective heat transfer by mechanically stirring fluid over the outer surface of a heat exchanger. A stirring mechanism is described which revolves rapidly around a heat exchanger surface in a stream undergoing heat transfer. During rotation, the stirring mechanism is supported near an end of the stirred heat exchanger by a central bearing and drive means. It is also supported over an extended length of the stirred heat exchanger surface by the hydrodynamic action of the stirring mechanism relative to the heat exchange surface without need for an additional central support bearing. The stirring mechanism uniformly turbulates the fluid film over the outer surface of the heat exchanger where heat transfer resistance normally occurs without imposing a pressure drop in the fluid stream undergoing augmented heat transfer. Compact and inexpensive heat exchangers are described which may be used in refrigeration, heating-cooling, and energy conservation systems.

Abstract: Non-contact heat exchangers comprise a gas carrying duct which has fluid carrying tubes inserted therein so that hot gas may heat the tube fluid. This simple principle is extrapolated into a heat recovery steam generator for a combined cycle power plant where hot gas turbine exhaust gases are used to heat steam turbine feed water in order to produce steam. A noise/vibration problem may be generated at certain gas turbine loads which create stimulus frequencies at or near boiler tube response frequencies. The invention proposes an optimum arrangement of upstream baffles which suppress the stimulus frequency generated by the gas flowing through the duct.

Abstract: A heat exchanger in which the main component is formed of a plurality of elongated strips of rigid heat conductive material. The strips are generally transversely aligned and wound into a coil formation in which each of the surfaces of each strip is disposed in facing relation to the opposite surface of an adjacent strip in the coil. Each pair of facing surfaces is ridged to provide passage defining portions and force transmitting portions with certain of the strips having both end edges thereof sealingly secured to the corresponding end edges of an adjacent strip so as to define a longitudinal fluid passage having a coil formation other of the strips have both end edges thereof disposed out of sealing engagement with corresponding end edges of the adjacent strip so as to define a transverse fluid passage.

Abstract: The device comprises a modulating device for modulating the action of a shifting device. The latter axially shifts the camshaft of the engine which camshaft varies the timing and the extent of opening of cylinder valves in accordance with its axial position. The arrangement is such that the action of the modulating device is controlled by the position of the accelerator pedal. Moreover, this arrangement constitutes the sole device for controlling the acceleration of the engine to the exclusion of an accelerator pedal-actuated throttle.

Abstract: An internal combustion engine is disclosed which includes a plurality of cylinders split into first and second groups, the first group of cylinders operative regardless of engine load conditions and the second group of cylinders inoperative when the engine is under low load conditions.

Abstract: Disclosed herein is a rotary engine operable as an internal combustion engine or powered from an external source, the engine comprising essentially three parts: (1) an outer housing or body, (2) a valve shaft extending axially through the body and having an eccentric mounted thereon, and (3) a rotor journalled on the eccentric. The shape of the internal surface of the housing and the rotor is such as to define a plurality of variable volume working chambers between the rotor and the housing. The rotor and internal surface of the housing may be cylindrical with the variable volume working chambers formed by sealing means projecting from the rotor in contact with the internal surface of the housing. The rotor and internal surface of the housing may also have a multi-lobed configuration with there being one less projecting lobe on the rotor than lobes in the housing with the projecting lobes of the rotor being essentially the same size and shape as those of the housing.

Abstract: A knock detecting apparatus for internal combustion engines, includes at least two vibration detectors having different resonance characteristics and encased in one container. The vibration detectors are comprised by piezoelectric devices (bimorph cells) or magnetic devices having reed members of magnetic material. The vibration detectors are interconnected by a lead wire to combine the outputs thereof and to produce a cumulative output.

Abstract: In a distribution type fuel injection system, the injection advance angle, or the relative angular position at which fuel injection begins, is controlled by a first spring loaded piston (44). The spring force is opposed by pressurized fuel from a pump (14), the pressure increasing with engine speed. A second spring loaded piston (49) moves the first piston (44) to an advanced position for starting the engine and is retracted when the fuel pressure reaches a certain value to retard the advance angle in an idling speed range. The fuel pressure moves the first piston (44) to progressively advance the angle in a higher speed range. An O-ring (61) is provided to an end of the second piston (49) which abuts against an end wall (53) so that the fluid pressure receiving area of the second piston (49) is small when the second piston (49) abuts against the end wall (53) but is greater when the second piston (49) is moved away from the end wall (53).

Abstract: A preheating device for the inlet manifold of an internal combustion engine, comprising at least one probe projecting into the exhaust manifold of the engine connected via a heat-conductive metallic rod or pipe to a second probe projecting into the inlet manifold, for transferring heat from the exhaust manifold to the fuel-air charge flowing through the inlet manifold. The probe disposed in the inlet manifold may be provided with an electrical heating element such as to preheat the interior of the inlet manifold prior to starting the engine, and providing heat to the fuel-air charge during cold starts of the engine.

Abstract: A trigger device for facilitating pulling bow strings and for quick release of the taut bow string and arrow, the quick release being actuated by either one or both of two mechanical links to a latch mechanism. The links are respectively actuable by the application of pressure by either or both of the archers thumb or small finger to a corresponding slide member housed in passages of a T-shaped passageway within a T-shaped housing. The housing is contoured for gripping by a hand. The slide members are each linked to a pivotable member which is engaged with the latch for the opening thereof.

Abstract: A stove construction including a firebox that defines a combustion chamber. Air is supplied to the upper portion of the combustion chamber through a preheat manifold having outlet apertures spaced along the sides. Air is drawn from the atmosphere into the manifold where it is preheated and discharged in the form of jets toward the sloping side walls of the firebox and into the flow path of the waste gases of combustion. Due to the restriction to flow caused by baffles located in the spaces between the sides of the manifold and the sloping sidewalls, a portion of the mixture of air and waste gases is directed downwardly along the surface of combustion plates, which are spaced from the walls of the firebox, back toward the primary combustion area. The waste gases are further combusted as they pass downwardly along the heated combustion plates. The recirculation achieves complete combustion of the waste gases.

Abstract: Hinged doors are provided on the front of a stove for sealably closing across a large opening through which logs can be loaded into a firebox within the stove. A cylindrical draft chamber is formed on an exterior surface of one or each of the doors. A draft cap is rotatable on a threaded stud which is coaxially secured in the cylindrical draft chamber. The draft cap includes an annular flange forming a sliding close-tolerance fit with an interior cylindrical wall of the draft chamber so that the cap can be rotated to vary the size of the draft chamber to selectively restrict the flow of air from a source through the draft chamber to the firebox whenever the doors are closed.