Abstract: A main needle holder is disposed above a needle plate, and has a screw portion for fitting a needle bar. A sub needle holder is fitted to the main needle holder by a set screw so as to be adjustable in position. Fitting position of the sub needle holder to the main needle holder is changed when loosening the screw, so that the interval of the plural needle is widened or narrowed in the longitudinal direction. Plural needles are individually fitted to the needle holders, and penetrate through a needle hole of the needle plate when descending. The fitting position of the sub needle holder to the main needle holder is changed by a longitudinal slit formed linearly on the main needle holder, and the cloth penetration lines by at least two needles of plural needles can be mutually set along in a narrow width.

Abstract: A take-up cam phase adjustment structure of looper thread take-up apparatus of a sewing machine includes a rotary shaft rotatablly mounted in the sewing machine. A thread-guiding plate mounted on the housing for correspondingly pressing a stitching thread against the rim of the take-up cam. A transmission mechanism connected between the lower driving shaft and the rotary shaft. The transmission mechanism includes a driven wheel rotatablly mounted on the rotary shaft. The take-up cam phase adjustment structure includes a locking member for locking the driven wheel on the rotary shaft and a turning section disposed at one end of the rotary shaft. After the second locking member is unscrewed and loosened, by means of rotating the turning section, the relative radial positions between the take-up cam and the lower driving shaft is drivingly adjustable.

Abstract: A transverse longitudinal-cylinder sewing machine includes an automatic thread loosening device, a tension adjustment mechanism, an automatic thread cutting bi-directional solenoid device and a differential fabric driving teeth displacement control device. The differential fabric driving teeth displacement control device consists of a primary transmission mechanism, first and second push mechanisms, a rocking mechanism, first and second adjustment mechanisms that are co-axle, and first and second fabric driving mechanisms located inside a cylinder normal to the co-axle. The axial direction of the cylinder is directed towards the operator so that the axis of the cylinder is normal to the entire transverse work station of the sewing machine.

Abstract: A textile fabric comprising a plurality of pieces of fabric material cut into strips, which are then placed adjacent to one another and interlaced. The interlaced strips are situated transverse of one another and allow for overlapping edges. Recessed from these edges along a generally parallel line are rows of stitching employed to join the pieces of fabric. The result enables the appearance of a simulated patchwork design.

Abstract: A method and apparatus are provided for accessing a cable or pipe (9) buried underwater in a layer of material (10). The method comprises urging a tool (1) through the layer of material (10) by fluidising the material adjacent the tool (1) such that the tool may be positioned at or adjacent the position of the buried cable or pipe.

Abstract: A device secured to a submersible portion of a boat lift to stabilize the submersible portion of the boat lift from unwanted lateral movement. Elongated pipe-like devices are attached to a submersible portion of a boat lift in proximity to a piling. The device is mounted to the submersible portion of a boat lift so that movement caused by wind, wave, or current action that would force the submersible boat lift into lateral motion will be stopped by the pipe-like device, which comes into contact with the piling before the lateral motion becomes so large as to be undesirable.

Abstract: A sea chest cover for providing access to the sea chest of a ship. The sea chest cover includes both a cover element and a liner element received within the interior of the sea chest and is fabricated essentially entirely of one or more viscoelastic materials, preferably either polyethylene or polyurethane. Materials can be also made of copolymers, which may be laminated, and compression molded or portions may be blow molded. Fabrication of the sea chest cover from a viscoelastic material reduces or eliminates corrosion and erosion problems. It also minimizes marine organism and ice build-up. The result is a reduction in the expense of associated with maintaining such covers. The sea chest cover can also include an additive to reduce bacteria and algae growth and be irradiated with gamma rays for increased strength.

Abstract: A launcher for torpedoes and underwater vehicles includes an inlet recess in fluid communication with a shutterway recess. A primary shutterway is provided both for ejection of the vehicle and for supplying fluid intake to the launcher. A pump circulates fluid from the inlet recess to the shutterway recess, and a launch tube houses a vehicle such as a weapon, within the launcher prior to launch thereof. A slide valve and impulse tank combination are positioned intermediate the pump and the launch tube, such that the slide valve controls a flow of fluid to the launch tube. A guide can is positioned at the shutterway recess for guiding the vehicle from the launch tube to an exterior of the launcher and fluid within the launcher is continually moderated to enable selective launch of the vehicle with a fluid force.

Abstract: A winglet for mounting on a trailing end of a flexible line to be towed by an underwater vehicle includes an internal collar member for connection to an inside surface of the line at the trailing end thereof, an outer collar member for connection to an outside surface of the line outboard of the internal collar, and connection means for fixing the internal and outer collar members to the line trailing end. A plurality of fins are mounted on an outside surface of the outer collar member and extend outwardly from the outer collar member.

Abstract: A system for docking a boat under substantial power in calm or rough seas includes a modified trailer platform having goalposts that guide the boat onto the platform. An elastic harness is attached to either side of the trailer platform and is positioned to interface the V-shaped bow of the vessel. A latch on the bow snags the harness as the vessel is being docked. The latch has a spring-biased and weighted cam that moves to an open position upon the harness contacting the cam and that then rotates to a closed position once the harness passes the cam. The harness then enters a hook formed by the latch and the closed position of the cam retains the harness in the hook. The expandable and retractable harness dissipates the kinetic energy of the docking vessel and assists in bringing the vessel to a rest.

Abstract: A track has a housing with a bore therein that extends from a first end to a second end, a linear slot at the top of the bore, a radial projection perpendicular to the linear slot, an axial groove in the bore, a plurality of radial openings that extend through the radial projection, a first leg thereon tangent to the top and a second leg tangent to the bottom of the bore. First and second cylindrical members on a ladder are located in the bore and a bolt inserted into each radial opening. Each bolt has a head that is located in the axial groove and a shaft that extends through an opening in a deck on a watercraft. A nut attached to each shaft such that the legs and a base on the radial projection are urged into engagement with the deck to affix the ladder to the deck.

Abstract: A self-retracting step assembly is attached to a swimming platform provided on the rear of the hull of a boat. The self-retracting step assembly includes a ladder comprising a series of telescoping tubes which enable its extension and retraction. The step assembly including the ladder assembly are attached to the swimming platform in a position in which the ladder is capable of extending into the water wherein the watercraft or boat floats. The telescoping ladder assembly can be extended and placed from a normally horizontal position into an inclined position wherein at least the last step of the ladder reaches the water. The energy for extending the ladder is supplied by a human user. The step assembly includes a motor or mechanical means for storing the energy used for extending the ladder. The ladder assembly is locked into the extended and inclined position by an improved mechanism that is located within the assembly attached to the swimming platform.

Abstract: A control system to control the descent of a seafaring vessel, such as a lifeboat, into water is disclosed herein. The control system, and an accompanying method, control the descent speed of the seafaring vessel to minimise the possibility of setback after splashdown, and thus increase the probability of a safe and orderly launch.

Abstract: Wetness indicating compositions having improved colorant retention and durability and to wearable articles comprising this wetness indicating composition are provided.

Abstract: An indicator having a character plate capable of making indicative characters emit light is provided, wherein a metal character plate 30 is provided with cut-out portions 30a being cut out along the peripheries of respective indicative characters, a back light source emits light on the back of the metal character plate 30, and a light-transmissive plate 40 are provided with projecting portions 40a to fit in cutout portions 30a of the metal character plate 30.

Abstract: A calculated medicine dose dispensing apparatus includes a medicine bottle and a calculated dose medicine dispenser specific to the medicine bottle and a particular medicine. The medicine bottle has a neck and a bottle cap installed on the neck. The dose dispenser includes a cup in the shape of a truncated cone with a large diameter open end and an end wall closing the small diameter end. The end wall has a circular indent defined by an indent sidewall. The dose cup fits on the bottle cap with the large open end facing down and the bottle cap frictionally installed in the cup indent. A dial assembly is installed on the dose cup on the exterior of the end wall. The dial assembly calculates the proper dose of the medicine for the patient according to a patient parameter such as weight. The dial assembly includes a dial and a data disc. The data disc is installed on the dose cup end wall and carries at least two information sets that are circularly arranged, spaced apart information bits.

Abstract: A mobile food dispenser includes a shell, a controller, at least one drive motor for moving the dispenser across a surface in response to direction from the controller, at least one sensor configured to detect the presence of an animal, and at least one compartment including a hatch mechanism for controlling an animal's access to the interior of the compartment, wherein the hatch mechanism is actuated by the controller, and wherein the controller is configured to move the dispenser and actuate the hatch mechanism to stimulate an animal, in response to a detected presence of the animal.

Abstract: A concealed stall door latch is installed in a sliding stall door. The sliding stall door includes a bar portion disposed on a top thereof. A handle channel is preferably disposed on one side of the bar portion. A single end channel terminates each end of the sliding stall door. The concealed sliding door latch is preferably slidably retained inside the handle channel and the end channel. The concealed sliding door latch includes a latch rod. A handle preferably extends through the handle channel from the latch rod. One end of the latch rod is biased to extend past a perimeter of the sliding stall door. A latch retainer is positioned adjacent the one end of the latch rod. The latch rod is retracted by the handle to allow the sliding door to be moved.

Abstract: Products and methods for reducing tartar on the teeth of a pet are provided. In an embodiment, a chewable product that enhances dental hygiene in a pet is provided comprising a body having a continuous phase and a discontinuous phase in such a proportion so that the force required to penetrate the product is greater than an anticipated bite force exerted by the pet during a normal biting event, and below the maximum force that the pet may periodically exert.

Abstract: Provided is an animal tethering device for confining an animal to a location and allowing it to move freely within a prescribed area, while preventing entanglement. The device includes a central shaft through which a spool is rotatably and retractably attached. The device also includes a housing which may resemble a sports ball or other desired ornamental design. The device provides optimum rotation by allowing forces in the horizontal plane, and also offers maximum strength in the entire spool assembly.

Abstract: The invention relates to a retractable leash for animals, having a housing containing a spring-biased reel in which the remaining length of leash can be taken up and which is stoppable by an actuating mechanism for adjustment of the maximum extension length of the leash as required, and by providing for the slack section of the leash to be taken up automatically by the reel when this maximum extension length is not being used, thus ensuring that the leash is always taut without restricting the animal's freedom of movement unnecessarily.

Abstract: A fuel-fired boiler having a supply fan for providing essentially all of its combustion air requirements and has a non-aspirating type burner section to an inlet portion of which pressure regulator apparatus is coupled, the pressure regulator apparatus having a predetermined pressure regulation setting. Fuel delivery apparatus is coupled to the inlet of the pressure regulator apparatus and is operative to deliver thereto, from sources thereof, a selectively variable one of (1) a first fuel at a pressure greater than the pressure regulation setting, and (2) a second fuel at a pressure less than the pressure regulation setting, the second fuel having a Wobbe index greater than that of the first fuel. The design of the fuel delivery apparatus permits the burner section firing rate to remain essentially constant, without modifying the burner section, regardless of which of the two fuels is being utilized.

Abstract: Devices and methods for controlling a boiler system. One illustrative method includes controlling the bypass temperature by increasing the firing rate of the boiler. Further methods include bypass temperature control methods wherein both regular and fast control methods are used, where the regular method operates to control bypass temperature by using, first, a bypass valve, and second, possible increases in firing rate. The fast control method responds to particular situations suggesting potential condensation in a primary heat exchanger to increase firing rate without waiting for a bypass valve to fully open. Further embodiments include controllers programmed for or containing programming for performing steps of the method embodiments, as well as systems incorporating such controllers.

Abstract: A method for adjusting coolant temperature in an internal combustion engine (2), whereby the coolant circuit thereof contains an electrically driven coolant pump (3) and an electrically controllable bypass valve (4). If the setpoint value of the coolant temperature changes in an abrupt manner, the rotating speed of the coolant pump (3) rises during the short interval in order to reduce the dead time required for adjustment. A Smith controller, which takes into account dead times of the system, is used to regulate the bypass valve.

Abstract: A free piston engine is configured with a pair of opposed engine cylinders located on opposite sides of a fluid pumping assembly. An inner piston assembly includes a pair of inner pistons, one each operatively located in a respective one of the engine cylinders, with a push rod connected between the inner pistons. The push rod extends through an inner pumping chamber in the fluid pumping assembly and forms a fluid plunger within this chamber. An outer piston assembly includes a pair of outer pistons, one each operatively located in a respective one of the engine cylinders, with at least one pull rod connected between the outer pistons. The pull rod extends through an outer pumping chamber in the fluid pumping assembly and forms a fluid plunger within this chamber. The movement of the inner and outer piston assemblies during engine operation will cause the fluid plungers to pump fluid from a low pressure container into a high pressure chamber as a means of storing the energy output from the engine.

Abstract: An internal combustion engine (10) including at least two radial cylinders (17) disposed with their axes coplanar and equi-angular located relative to each other. The cylinders (17) meet to form a common combustion chamber (18). A piston (20) is located in each of the cylinders (17), each piston (20) cooperates with a cam profile (23) formed by the inner wall of a rotor (13). The cam profile (23) is rotationally symmetrical and includes the same number of lobes (26) as pistons (20) with each lobe (26) projecting radially inwards. The lobes are equi-angularly disposed about the inner wall of the rotor (13). In contrast to a conventional crankshaft driven engine, the cammed pistons (20) may move according to a non-sinusoidal time-velocity function. The lobes (26) may be modified in shape, for example, by filing or other reshaping, in order to customize the pattern of movement of the pistons (20) so as to alter the operating characteristics of the engine (10).

Abstract: Blower forces fuel/air mixture into bore of cylinder head against small diameter piston of compound piston assembly, forcing assembly down in engine cylinder, permitting fuel/air mixture to enter main cylinder of engine in which it is ignited. Exhaust forces assembly to bottom of its stroke. Roller bearings on large diameter piston engage sloping surface on swash plate causing rotation of drive shaft.

Abstract: An engine has a lubrication system configured to lubricate at least a portion of the engine with lubricant. The lubrication system has a lubrication pump that periodically pressurizes the lubricant toward the portion of the engine. A first sensor senses an engine speed. A second sensor senses an engine load. A third sensor senses a temperature of the lubricant or the engine. A control device controls the lubrication pump. The control device determines a frequency of periodic pressurization by the lubrication pump based upon outputs from the first and second sensors. The control device determines a pressurization time of the lubrication pump based upon at least one of outputs from the first, second and third sensors.

Abstract: A lead frame disposed within the confines of an engine cover, having an insulating portion and an electrically conducting portion. The conducting portion has at least one electrically conducting interconnect. Both the insulating portion and the electrically conducting portion form an integral piece for retaining and accurately positioning devices within an internal combustion engine. The lead frame includes a plurality of retaining elements for retaining or positioning of at least some of the devices; and an electrical connector member extending outside the confines of the internal combustion engine, the electrical connector member having a plurality of electrically conducting terminals in electrical communication with at least some of the devices within the internal combustion engine by means of the at least one electrically conducting interconnect, whereby at least some of the devices are retained and accurately positioned within the internal combustion engine.

Abstract: A controller restricts an operation amount of the variable valve actuation mechanism of a fluid pressure operated type such that increase in the valve overlap amount of an engine is restrained when the engine is in a transient operation state in which the output of the engine increases. When the controller determines that the variable valve actuation mechanism is in the locked state, the controller relaxes the restriction imposed on the operation amount of the variable valve actuation mechanism. Hence, a decrease in follow-up performance of valve properties to desired properties is restrained while restraining temporary stagnation of increase in engine rotational speed caused by vehicle acceleration.

Abstract: A valve lift mechanism, in particular for internal combustion engines of motor vehicles, has a driven cam element, a valve control member which can be driven (translational movement or pivot rotation) by the cam element, and a flexible enveloping element, wherein the cam element is rotationally mounted. The enveloping element may be formed of an open loop with two ends connected by a holder of said valve actuator, and it is movably connected to the valve control member in the plane perpendicular to the axis of rotation of the cam element.

Abstract: A line of small internal combustion engines, including twin cylinder engines and single cylinder engines. The engines each include a crankcase, and one or more cylinder members attached to the crankcase, the cylinder members being separate components from the crankcase. A number of different crankcases are provided for various types of single and two cylinder engines, the crankcases having common mounting structure to which the cylinder members may be attached. Thus, the manner in which the cylinder members are attached to the crankcases is the same for each of the different types of crankcases. Two different types of cylinder members are provided, one having a side valve or “L-head” valve train, and the other having an overhead cam (“OHV”) valve train. The cylinder members are therefore modular components which may be selectively used in a variety of different types of engines.

Abstract: A balancer device for engines, in which first and second balancer shafts are arranged in parallel to a crankshaft and the crankshaft rotatingly drives first and second balancer weights at the same speed as that of the crankshaft, characterized in that the first balancer weight is arranged on one end of the first balancer shaft in a direction along the crankshaft, the second balancer weight is arranged on the other end of the second balancer shaft in the direction along the crankshaft, and the first and second balancer shafts are made close to the crankshaft so that loci of rotation of the first and second balancer weights partially overlap a locus of rotation of that portion of the crankshaft, which is coupled to a conrod when viewed in the direction along the crankshaft.

Abstract: An internal combustion engine; having block valley radiator core, with electrical water pump and air cooling fans, cooling and circulating water through block water passages, and having block valley oil reservoirs positioned under block valley radiator core for oil storage cooling and directing oil through oil passages. Includes; cylinderhead having horizontally rotating valveshaft; having separate axially spaced intake and exhaust valvepockets between ringseals, being timed rotated, centrally above dual spark plug ignition combustion chambers, over piston cylinders, and communicating centrally between cylinderhead intake and exhaust chambers—having port passageways, with connected intake and exhaust manifolds, providing strainfree; opening and closing combustion chambers, highspeed valvepocket(s) rotation, highflow air-fuel intaking and combustion exhausting—velocity capabilities. The valveshaft provides installation and removal without removing cylinderhead from engine block.

Abstract: A method is disclosed for positioning the crankshaft of an engine. The method comprises the steps of providing a first hole in the flywheel, providing a hole in a stationary part of the engine to line up accurately with the hole in the flywheel once during each crankshaft revolution, manually cranking the engine until the holes in the flywheel and the engine are aligned, and inserting a pin into the aligned holes to lock the crankshaft in a predetermined angular position.

Abstract: An internal combustion engine providing a strong mounting attachment for an engine accessory component on a light weight element of the engine body that is provided with a reinforcement for another primary purpose.

Abstract: A reciprocating piston engine (or motor) includes plural reciprocating pistons operatively connected to a single intermediate oscillating shaft, and a crankshaft having a single crank pin operatively connected to the oscillating shaft, so that the crankshaft experiences one complete revolution for each back-and-forth reciprocation of the pistons. The connection between the pistons and the oscillating shaft can include a rack-pinion drive system or a link-lever drive system. The connection between the oscillating shaft and the crankshaft can include a sector gear in mesh with a toothed rack that operates a connecting rod attached to the crank pin; alternately a lever-connecting rod drive mechanism can be used between the oscillating shaft and the crankshaft.

Abstract: Disclosed is an engine of a personal watercraft having a water jet pump at a rear end thereof, in which a center of gravity of the engine is located rearward for improvement of planing capability of the watercraft. The engine comprises: a crankcase having a front end wall and a rear end wall; a crankshaft provided inside the crankcase; a generator provided at an output end portion of the crankshaft, the generator including a rotor fixed to the crankshaft; a starter motor provided on an output end side of the crankshaft outside the crankcase; and a clutch provided between the starter motor and the rotor of the generator, for connecting/disconnecting the starter motor to/from the rotor.

Abstract: During start-up of an in-cylinder fuel injection spark ignition engine (1), an engine controller (21) calculates a start-up fuel injection pulse width TIST on the basis of a cooling water temperature Tw, an engine rotation speed Ne, and a fuel supply pressure Pf to a fuel injector (8) (S1). When the fuel supply pressure Pf exceeds a required fuel pressure, the engine controller (21) executes stratified combustion by means of compression stroke fuel injection. By setting the required fuel pressure precisely in accordance with a start-up condition defined by the start-up fuel injection pulse width TIST and the engine rotation speed Ne, the opportunities for stratified combustion during start-up increase, and the amount of hydrocarbon discharge decreases.

Abstract: An internal combustion engine includes an intake port leading to an engine cylinder. The intake port is divided into first and second passage section by a partition extending in the intake port in a longitudinal direction of the intake port. A gas motion control valve is arranged to open and close an upstream end of the second passage section. A connection passage connects an upstream end portion of the second passage section to the first passage section. A bulge is formed in a first part of a circumferential region surrounding the downstream port end so as to prevent air from being drawn from the cylinder into the second passage section.

Abstract: A compression release brake system 10 includes a hydraulic apparatus 12 for controllably opening at least one exhaust valve 14 of at least one cylinder 16 of an engine in response to motion of a cam actuator 12. The system 10 includes a master piston assembly 40 having a master piston 42 engageable with the cam actuator 12. The master piston 42 includes a compressible piston pin 56. A slave piston assembly 44 is hydraulically linked to the master piston assembly 40 and includes a slave piston 46 engageable with the at least one exhaust valve 14.

Abstract: In fuel injector including an accumulator and an intensifier, fuel is injected such that an injection control valve and a piston control valve are individually controlled, an operational phase difference therebetween is regulated, and at least one of a maximum injection pressure, a rate of increase of an injection pressure at the start of an increase of pressure, a rate of decrease of the injection pressure at the completion of injection, a pilot injection pressure, and an after injection pressure of fuel injected from a fuel injection nozzle is arbitrarily changed. Namely, a pressure during a movement from a base common rail pressure of the accumulator to a static maximum pressure statically determined by an operation of the intensifier is positively used as a control factor of injection, whereby a fuel injection pattern can be implemented with an extremely high degree of freedom.

Abstract: A pulsation reducing system for a fuel line of an internal combustion engine, especially for an automotive engine equipped with an electronic fuel injection system is provided. The system includes a fuel delivery rail, a fuel tank, and a longitudinal main fuel pipe. A first flexible tube is arranged between the fuel delivery rail and the main fuel pipe. A second flexible tube is arranged between the main fuel pipe and the fuel tank. A small-ID tubular portion is arranged within the first tube or near the connecting portion of the first tube. The inside diameter of the small-ID tubular portion is smaller than that of the main fuel pipe. The length of the small-ID tubular portion is set between 10 to 50 times the inside diameter of the small-ID tubular portion itself. Thus, standing waves and resultant pressure pulsations caused by the fuel delivery rail are reduced by the small-ID tubular portion.

Abstract: A manifold has a supply inlet communicating with a plurality of spaced supply ports; and, has associated with each supply port a separate control pressure passage. A gasket has a plurality of spaced bosses, each with a valving cavity with an electrically operated valve received and ported in the cavity. Each valving cavity has a supply port communicating with one of the supply ports on the manifold and a control pressure outlet port communicating with one of the control pressure passages on the manifold. A plurality of electrically conductive strips are embedded in the gasket and each is connected to a terminal pin in a receptacle shell formed on the gasket. The remote end of each of the conductor strips is exposed adjacent a valve and makes contact with a terminal on the valve when the valve is received in the respective valving cavity. A common retaining bracket is attached to the manifold and retains the valves and gasket as an assembly on the manifold.

Abstract: An LPG fuel tank for motor vehicles is provided, inside, with a support, on which there can be installed in a rapid way a pump assembly including a supply pump and the corresponding electric actuating motor. Preferably, the support is also used for installing a level-sensor assembly within the tank.

Abstract: A powdered metal bearing (40) that guides a pintle (42) in an EGR valve (20) is sealed against infiltration of exhaust gases by mechanical processing or by applying a sealant.

Abstract: Method and arrangement for cleaning an EGR cooler of an exhaust gas recirculation system by detecting an excessive particulate accumulation condition in the EGR cooler and causing liquid-state moisture to be introduced in the EGR cooler thereby enabling a reduction of the excessive particulate accumulation from the EGR cooler.

Abstract: An output signal from a downstream-side exhaust gas sensor is fed back into a fuel injection rate so that the air-fuel ratio of the exhaust gases flowing out from a catalyst may match a reference value. In this sub-feedback control process, the integral value of the deviation between the output signal of the downstream-side exhaust gas sensor and a reference value is calculated, and the resulting integral-data signal is smoothed. A learning value for compensating for the permanent error included in an air-fuel ratio signal from an A/F sensor is learnt from the integral-data signal generated by the above smoothing operation.

Abstract: A compound archery bow having an adjustable cable guard. In one preferred embodiment, the cable guard includes a swing arm with an adjustable cable saver. In an alternate preferred embodiment, a compound archery bow includes a cable guard and a fall-away arrow rest assembly.

Abstract: An air-powered projectile launcher. A double-acting piston within a pump tube is employed. A separate magazine tube is used to hold a plurality of projectiles. One end of the magazine tube feeds into a barrel assembly. The opposite end is closed by a one-way valve. The muzzle of the barrel is closed by a muzzle valve. When the piston is pulled through a back stroke, an air manifold directs the flow to induce a vacuum in the end of the magazine tube proximate the barrel. The vacuum closes the muzzle valve and opens the one-way valve on the opposite end of the magazine tube. The vacuum then pulls the first projectile into the barrel. When the piston is pushed through a forward stroke, pressure is directed behind the first projectile and in front of the second projectile. The second projectile is forced back into the magazine tube. The pressure within the magazine tube closes the one-way valve, effectively making the second projectile the base of a closed firing chamber.