Abstract: There is disclosed an event counting and reporting heart pacer which is useful for patients who suffer from bradycardia. The pacer operates in a demand mode with a 2.5-second escape interval. A count is maintained of the number of pauses each of which exceeds this escape interval. Four successive pauses, each of which exceeds 2.0 seconds but is less than 2.5 seconds, are treated as a single 2.5-second pause. Following the detection of each pause, the escape interval is reduced to 1.2 seconds and the counter is inhibited from further operation; the counter is enabled and the 2.5-second escape interval applies once again only after a spontaneous heartbeat is detected within 1.2 seconds of the preceding beat. When a maximum count of 128 pauses is reached, the system thereafter operates with fixed 1.2-second escape interval.

Abstract: A target material comprises a rubber sheet coated with a thermoluminescent material. When a bullet penetrates the target, as a result of the temperature rise the thermoluminescent material thermoluminesces indicating where the bullet went. A range is disclosed in which images of targets are projected onto the target material.

Abstract: An electrically operated roller door driving mechanism for operating a roller door comprising a reversible electrical motor fixedly mounted to one of the roller door supporting drum wheels and housed within the core of the roller door curtain, the motor and drum wheel being arranged to rotate simultaneously, and a ring gear operatively associated with said motor via a reduction gear mechanism, the ring gear being capable of being held stationary with respect to the rotating drum wheel but also being capable of rotating in unison with the drum wheel to thereby enable the roller door to be manually opened and closed in the event of a motor malfunction or power failure.

Abstract: A signal-to-noise improving system is described which comprises a circuit input for incoming noisy analogue signals and a circuit output for digitally stored input signals which have an improved signal-to-noise ratio provided by the system and which have been reconverted to analogue form,said circuit input and said circuit output being connected to inputs of an analogue comparator arranged to give an output which signifies that the stored signal is either higher or lower in magnitude than the incoming signal or that the incoming signal is either higher or lower in magnitude than the stored signal,said comparator output being connected to a signal incrementor which is arranged to give a signal output which is the stored digital signal incremented higher or lower by a number digitally in response to either a higher or lower signal output from said comparator,a store for storing in digital from the so incremented input signals, the store output being connected to a digital to analogue converter 1 the output of w

Abstract: A pacer for controlling tachycardia, in which the coupled interval is scanned as well as the initial delay. The time parameters which are successful in terminating the condition are stored so that upon confirmation of another tachycardia event, the previously successful time parameters are the first ones to be tried. The unit also allows tachycardia to be induced by the physician so that the parameters which are programmable can be adjusted for optimum performance following a subsequent naturally occurring tachycardia confirmation.

Abstract: Deadbolt mechanism for holding a door in a closed position and including a deadbolt pivotally connected to the mechanism housing for movement into and out of that housing to adopt inoperative and operative positions respectively. A pin tumbler lock is used to operate the deadbolt and the lock barrel is rotated through 360.degree. during the change of deadbolt positions whereas the deadbolt swings through 90.degree. only. The drive between the lock barrel and deadbolt includes a pair of gear segments which engage during the 90.degree. travel of the deadbolt and are otherwise disengaged to permit the lock barrel to rotate free of the deadbolt. The drive also includes a pivoted arm which locates between side walls of the deadbolt and has a laterally extending pin slideably locating within a slot in each of the side walls. When the gear segments are engaged the arm is swung such that a camming action occurs between the pin and cooperating slots whereby the deadbolt is caused to move about its pivot.

Abstract: A spiral separator includes an upright column supported with its axis substantially vertical and adapted to receive at an upper end thereof a pulp of water and particles to be separated. The spiral separator also includes a plurality of helical turns mounted to said upright column wherein at least in a top portion of the separator there is provided a channel located on an outer part of the separator. The channel is initially narrow and deep and becomes progressively wider to enable the particles to obtain or maintain an initial velocity so as to maintain the flow of pulp without the coarser and/or less dense particles becoming stationary or stranding and wherein the coarser and/or less dense particles may be retained in an outer section of the channel and the finer and/or denser particles may move toward an inner section of the channel and be retained in said inner section.

Abstract: This invention relates to the separation and purification of the platinum group metals; more particularly it relates to the separation of mixtures of Pt and/or Pd from Rh and/or Ru.

Abstract: Lead is selectively recovered electrolytically from a mixture of metal sulphides in an aqueous chloride electrolyte by controlling the rate of agitation and oxidation conditions so that metal sulphides other than lead remain substantially undissolved.

Abstract: There is disclosed a dual chamber pacer which offers several advantages over prior art devices. Although the pacer requires for its operation AV delay and VA delay parameter values, most physicians characterize dual chamber pacers in terms of AV delay and ventricular pacing rate. The pacer of the invention can be programmed under external control by the physician setting values for the parameters with which he is most familiar. A subtractor in the pacer forms the difference between the reciprocal of the ventricular pacing rate and the AV delay to derive the value of the VA delay. The pacer is also characterized by active recharge of the atrial output capacitor so that a very short ventricular refractory period following atrial pacing may be provided. A single maximum rate timer prevents the generation of excessively fast ventricular stimuli, whether due to the ventricular or atrial sub-systems, or even if atrial contractions are being sensed at too rapid a rate.

Abstract: The invention relates to an electro-chemical cell having an electrolyte comprising water, a halogen other than fluorine, a halide other than fluoride, which is not oxidized by the halogen as a soluble salt, and a stable, saturated, organic nitrile or dinitrile containing from 2 to 5 carbon atoms or a mixture thereof, said electrolyte being composed such as to exist in two phases, a first phase being halogen and nitrile-rich and a second phase being water-rich and containing halide salt, the cell having an inert electrode in the halogen and nitrile-rich phase and an electrode, containing or contacting halogen oxidizable material, in the water-rich phase. The electro-chemical cell of the invention is particularly applicable to systems containing zinc as the halogen oxidizable material.The use of the nitrile-rich phase reduces the degree of reaction between the halogen and the halogen oxidizable material.

Abstract: A wax composition has water repellent and adhesive properties, is cheap and has wide application in the manufacture and treatment of corrugated paperboard, fibreboard, particle board and other cellulosic materials. The liquid composition comprises 1-50 wt % of a wax, 1-30 wt % of a starch and 1-50 wt % of a formaldehyde based resin.

Abstract: A dial operated air pressure regulator produces forward, hold and reverse signals in an air operated control circuit which creates corresponding conditions in a hydraulic circuit. The regulator has a pair of spring loaded valves which slide axially in a pair of valve cylinders which in turn control the air flow in the circuit. The valves are depressed by face cams moulded into the dial; rotation of the dial in one direction causes one cam to operate one valve and produces a forward signal; rotation in the opposite direction causes the other cam to operate the associated valve to create the reverse signal; when neither valve operates, the hold signal results.

Abstract: A pool, such as a swimming or ornamental pool, has a bottom of sheet material and a vertical wall section of pliable sheet material, both of which may be of vinyl-coated sheet steel. A flexible extruded junction member is grooved to receive the edge portion of the pool bottom, and also the bottom edge portion of the wall section, each of which is held in sealed manner in the junction member by a resiliently deformable sealing strip driven into the junction member adjacent to the bottom and/or walls section.

Abstract: The invention relates to a digital loop sharing telephone system and also to a digital telephone for connection into such a system. The loop may be for a parallel telephone system or a party-line system. Each telephone is adapted to transmit data in an upstream direction on the loop, that is towards an exchange of the system, which data may originate from the telephone itself or a further telephone downstream thereof. Each telephone includes code detector circuitry and logic circuitry whereby if the telephone is the first to change to an off-hook or active condition it "seizes" the loop for exclusive data transmission to the exchange. In the case of a parallel telephone system any telephone going off-hook can receive incoming data from the exchange but only the first telephone to go off-hook can send data. In the case of a party-line system only the telephone which seizes the loop can receive data.