Showing papers on "Damper published in 1971"

Bag diaphragms and bag diaphragm operated air dampers

Abstract: The present invention deals with a bag diaphragm comprising one or more flattened extremely flexible bags assembled together, to be mounted between rigid plates at a variable mean distance and to be inflated in operation by a variable pressure difference, and with an air damper operated by means of a bag diaphragm as mentioned above, this air damper being suitable for air conditioning plants, in constant flow, or constant variable flow, or mixing appliances, in fresh air and return air ducts, where an air flow is to be controlled, the operation of the air damper being possible without any electrical or pneumatic energy supply system, due to the particular characteristics of the aforesaid bag diaphragm and particular design of the damper.

Interblade baffle and damper

Abstract: A baffle and damper assembly includes end plates for closing the opening between adjacent blade shanks, a connecting member extending between the end plates, retaining means to lock the assembly to its adjacent blades against the urging of centrifugal force, and at least one damper weight movably secured to the connecting member and adapted to bear against the blade platforms under the urging of centrifugal force.

Turbine blade damper

Abstract: A VIBRATION DAMPER FOR USE IN A TURBINE ROTOR OF A HIGH TEMPERATURE GAS TURBINE IS DISCLOSED. THE DAMPER WHICH IS X SHAPED IN OVERALL CROSS SECTION WITH A PAIR OF DAMPING LEGS, A PROTRUDING ASSEMBLY LUG, AND A PAIR OF POSITIONING LEGS IS LOCATED IN THE TURBINE ROTOR IN A CAVITY FORMED BETWEEN THE EXTENDED NECKS OF A PAIR OF ADJACENT TURBINE BLADES IN ONE DIRECTION AND END COVER PLATES IN THE OTHER DIRECTION.

Ventilated open-air indoor broiler having damper means and control therefor

Abstract: VENTILATED OPEN-AIR INDOOR BROILER HAVING DAMPER MEANS AND POSITIONABLE CONTROL THEREOF COMPRISING AN ENERGIZING SWITCH FOR ELECTRIC HEATING ELEMENTS.

Overhead-line oscillations and the effect of aerodynamic dampers

Abstract: The paper is an attempt to further the understanding of aerodynamic effects in the large-scale vertical oscillations of overhead lines, usually known as ‘galloping’. The energy per cycle dissipated by the aerodynamic drag is calculated, and then, assuming the lift coefficient of the cable to be less than some measured maximum value, the maximum possible amplitude of oscillation for a given windspeed is found. The theory gives a plausible value of the minimum windspeed at which the ‘clashing’ of conductors can occur, and also a physical explanation for the given amplitude reached. The theory is then applied to the problem of estimating the effect of aerodynamic dampers in reducing the amplitude of galloping. Such dampers have been used in Canada, but the theory justifying their use appears, to the authors, inadequate. The method of calculation leads to an estimate of the minimum effect such dampers can have, and, as an example, the authors have examined the performance of some cylindrical dampers proposed for use on twin lines where pairs of cables are suspended about 0.3 m apart.

Air flow control device

Abstract: Pneumatically operated air flow control devices for use in a variable air volume conditioning system, wherein air volume rate is normally controlled by temperature responsive means, and including pressure responsive means to override the temperature responsive means under prescribed conditions.

Combustion control valve means and system

Abstract: Combination control apparatus including means for supplying air to a furnace, means for supplying gas to the furnace, means responsive to heat demand for varying the air flow and means responsive to the rate of air flow for adjusting the rate of gas flow to maintain a constant fuel/air ratio. Preferably, an air damper or valve is located in an air inlet pipe to a blower and a gas supply pipe is also connected to the inlet pipe adjacent the blower. The blower feeds the mixture into the furnace. A modulating-type pressure regulating valve controls the rate of gas flow and means responsive to air pressure, located between the air valve and the blower, adjusts the modulating valve to maintain an outlet pressure that provides a fuel/air ratio that is substantially constant.

Vibration damper test machine

Abstract: A vibration damper test machine including a rotary mass elastic system and characterized by electromagnetic means for exciting the system in the form of an oscillating torque of resonant frequency to produce large torsional vibrations at an end of the system adapted to receive a torsional vibration damper. The electromagnetic excitation means is arranged such that an excitation frequency corresponding to a predetermined order of vibration and an excitation torque corresponding to the order of vibration amplitude can be induced into the mass elastic system to simulate conditions existing in a particular engine. An observed excessive amount of strain on the system at resonance provides an indication of malfunction of the damper.

Damper for ventilating air flow control for indoor open-air cooking device

Abstract: Positionable damper means for directional air flow control over an open cooking surface of a stove or broiler. The damper means is adaptable for positioning to determine air flow velocity and directional entrance into an air exhausting plenum chamber, and is selectively positionable to completely close the entrance to the plenum and thereby prevent back draft of outside air into a room.

Suspension struts for independent wheel suspension systems of motor vehicles

Abstract: A suspension strut for an independent wheel suspension of a motor vehicle comprises a telescopic damper with a helical compression spring arranged around the damper and seated at its ends on the cylinder tube and piston rod respectively of the damper. A wheel carrier is connected to the lower end of the damper cylinder tube and projects laterally therefrom. To compensate for the bending moment produced by the offset disposition of the wheel carrier relative to the damper axis, those portions of the convolutions of the helical spring which are disposed on the same side of the spring as the laterally projecting wheel carrier - corresponding, in use, to the outboard side of the spring convolutions - are constructed to have a greater polar resistance moment than the portions of the spring convolutions which are disposed on the opposite side of the spring from the spring carrier. The spring starting material may for instance be circularsection spring stock, which, prior to convolution, has its crosssection locally reduced in area or changed in shape, by metal removal or by press-forming, to produce the portions having a smaller polar resistance moment.

Damper system for suspension systems

Abstract: A system is disclosed for damping bearing systems and particularly for damping magnetic bearings by applying a conductive plate in close proximity to a strong magnetic field at one or both ends of the bearing system. Induced eddy currents in the conductive block oppose radial and axial vibrations which cause soft bearings, such as magnetic bearings, to malfunction and become dangerous at high rotational speeds.

Mechanical damping structure

Abstract: A body adapted to absorb energy, especially a shock or force damper, consists of a sponge or foam metal matrix with pores and, preferably, a filler of vermiculite or perlite in an expanded state. The body is predeformed through 5 to 35 percent of its original volume before it is employed as a shock or force damper.

Stability of a dual spin satellite with two dampers

Abstract: Linearized equations of motion for a dual spin satellite composed of a platform, a rotor, a platform-mounted damper, and a rotor mounted damper are solved by the method of averaging to obtain a closed-form first approximation solution. The results obtained are found to be in good agreement with numerically computed solutions. Analytical stability criteria are also obtained and verified by comparison with the results of Floquet analysis. The method offered in the paper is based on the established formalism of the method of averaging, and in principle will yield a complete solution to any degree of approximation desired. In this application, the solution is noted to be particularly accurate when the masses of the dampers are small with respect to the total satellite mass, which is the case in current satellite designs.

Air distribution apparatus

Abstract: Air distribution apparatus including an air distributor designed for connection to ductwork in a building and adapted to be mounted flush with a ceiling The distributor contains an adjustable plenum chamber rotatable about its axis for selectively determining the quantity and directing air through its outlet angularly outward in any direction into a room without using dampers or other air deflecting or directing vanes The absence of dampers or other members in the air stream minimizes air turbulence and sound noises while increasing the overall efficiency of the distributor

Damper device for railway vehicle automatic couplings

Abstract: A damper device for automatic couplings in railway vehicles has elastic and hydraulic parts, the hydraulic part being double-acting and having two chambers which are interconnected through a variable flow restriction, for example a nozzle formed in part by a shaped axial pin, such that the damping force varies progressively in response to movement applied to the device.

Mechanical isolator and damper

Abstract: A mechanical isolator and damper has been developed which can be adapted to isolate shocks and damp vibrations to ball bearings, flexural pivots, and other similar rotating and oscillating devices. It can also be used as a bushing for shafts where isolating and damping is required. The damper comprises concentric outer and inner tubular collars connected by leaf springs, the space between the two collars being filled with a shock absorbing substance, such as an elastomeric material. Vibration damping and shock absorption is provided for fixed or moving devices positioned within the inner collar.

Rotor system having viscoelastic lead-lag damper

Abstract: A rotor system for a helicopter or the like vertical lift aircraft in which lead-lag motions of a blade are effectively damped by a body of viscoelastic material that is stressed preferentially in shear by the lead-lag movement of the blade.

Temperature compensated adjustable damper unit

Abstract: An adjustable damper unit is provided which exerts a restraining torque on a shaft, the torque being directly proportional to the angular velocity of the shaft. Damping is provided by a magnetic restraint on a drag cup driven through the magnetic field of a permanent magnet by planetary gears. An external adjusting ring controls the magnitude of the magnetic restraint and thereby controls the damping rate.

Proportional motor actuator circuit

Abstract: A motor actuator circuit for use in heating and air conditioning and process control systems to selectively rotate a motor shaft which positions a damper or valve. A command signal, such as a voltage, or a potentiometer controlled by a sensing element of the system provides a signal representing the desired position for the damper and a sense potentiometer provides a signal representing the actual shaft position; a signal comparator circuit including a differential amplifier having an output switching stage is responsive to a potential difference between the signals to effect energization of one of a pair of motor windings, the energized one of the pair being determined by the polarity of the difference signal; and detent circuits derive a detent signal from the voltage across the other one of the motor windings for coupling to the amplifier input to increase the potential difference, the sense potentiometer wiper being linked to the motor shaft so that the potential difference decreases as the shaft rotates to the desired position, and the motor is deenergized when the desired position is reached.

Cable vibrator damper with moveable additional weights

Abstract: A Stockbridge vibration damper for cables having at least one weight of elongated shape in combination with at least one additional weight adapted to be removably attached to the outer surface of said elongated weight at any selected region along the length of the major axis of each said elongated weight.

Method for making a torsional vibration damper

Abstract: A fluidized bed coating method is used to cover the weight of a torsional vibration damper with a thin coating of a bearing material, such as nylon. Thereafter, the weight is rotatably mounted in a housing which is filled with a viscous damping fluid.

Apparatus for controlling the density of a fiber feed mat

Abstract: For controlling its fiber density during formation of a mat that is to be fed to the lickerin of a card or web forming machine, a pressure gauge is connected to the inlet duct of the suction fan that causes fibers to be drawn from a feed mechanism and laid down on a condenser to form the mat; and this gauge is geared to a pivoted or reciprocable damper in the duct to control air flow in the duct, thereby to control the density of the mat. The control damper may be positioned either at the inlet or the outlet side of the fan.

Damper apparatus with fluid seal

Abstract: Dampers operative in a duct system are provided with a hollow body that is connected to a source of fluid maintained at a higher pressure than that of the gases passed through the duct. Means are provided along the edges of the dampers to contain sealing fluid admitted thereto when the dampers are disposed in a fully closed position thus to provide a fluid seal that is effective to prevent passage of the gases conducted through the duct from one side of the dampers to the other.

Variable Parameter Nutation Damper for SAS-A

Abstract: This paper presents design objectives, functional description and in-flight performance of a variable parameter nutation damper for a dual-spin satellite. The damper consists of a torsion wire mounted pendulum which includes the capability of command changing the pendulum resonant frequency and damping constant in order to obtain optimum spin axis stabilization for both a dual-spin and single-spin spacecraft dynamical condition. State-of-theart features of this damper include: 1) taut-band suspension, for a pendulous mass, which has no mechanical friction of hysteresis, 2) magnetic circuit for changing the torque constant of the taut-band thereby changing the damper natural frequency, 3) chargeable magnet system for varying the damping coefficient, and 4) 7-bit optical readout for telemetering the damper motion. The damper weights 2.7 Ib and draws 20 mw power when functioning for dual-spin conditions. The minimum nutation damping time constant in this mode is 12 min with a predicted spin axis pointing accuracy of 1 min of arc. Stabilization to better than 2 min of arc has been achieved in orbit.

Front operated fireplace damper control

Abstract: This invention is for a control for the damper of a fireplace. The control may be operated from the front of the fireplace. This invention is adaptable for use in older and installed fireplaces and is also adaptable for use in new fireplaces or fireplaces which are about to be installed.

Fluid distribution device

Abstract: A heat exchanger for an air flow, comprising; a duct with a hump; a heat transfer matrix mounted on the duct within the hump in a spaced manner to make a free air flow passageway, a damper plate pivotally mounted on the matrix, a first plate having a plurality of first apertures and mounted on the duct, a second plate with a plurality of second apertures, a device for linking the second plate with the damper plate, and apparatus connected to the damper plate for holding the damper plate in a first or second position and moving the damper plate therebetween. The damper plate closes the free air flow passageway when the damper plate is in a first position, thereby forcing air to flow through the matrix, said damper plate covers a portion of the matrix when the damper plate is in a second position, thereby allowing air flow through the free air flow passageway, and an uppermost periphery of the first plate is contiguous to a lower periphery of the damper plate when the damper plate is in the second position.

A Single‐Coil Probe Damper for Pulsed Nuclear Magnetic Resonance

Abstract: A circuit design is presented for a probe damper suitable for single coil NMR probes which improves the time for ringdown following an rf pulse by a factor of 2.5. The damping is provided for a precisely controlled time and removed positively to enable the use of high‐Q single‐coil NMR probes for samples with very short T2's. The damper can be adapted for use with negative or positive transmitter gating pulses.

Delayed action dampers for air terminal units

Abstract: An air damper arrangement for a terminal unit that has separate positionable dampers located in the unit to provide for automatic air mixing in response to temperature requirements. In double duct systems, the dampers are mechanically linked in a unique way so that the hot air damper will not begin to open until the cold air damper is partially closed. In this manner, the cold air volume is reduced to a minimum quantity before the hot air is permitted to mixin the terminal unit. Another embodiment utilizes this linkage concept with terminal reheat bypass units to selectively control the dampers associated with the terminal unit heating coil thereby decreasing the volume of air bypassing the coil prior to utilization of same.

Motorized damper operator and control

Abstract: An electric motor driven operator and control for dampers of the gravity return type, such as used in chimney flues for fireplaces. The operator comprises an electric motor-gear speed reduction unit for driving a crank arm which engages with a pivoted member in an elongated slot in the latter. In each revolution of the output shaft of the driving unit the pivoted member opens the damper in the first half revolution, and then allows it to close in the remaining half revolution. The control comprises a two position selector switch, and limit switch operable in accordance with the motor shaft position to cause the motor to stop when the damper is in full open position, or when in completely closed position. Indicating lights are provided to indicate when the damper is in open position, and when the temperature in the region of the damper operator exceeds a predetermined high limit.

Thermostatic vacuum positioner

Abstract: An automatic temperature control system for air conditioning the passenger compartment of an automobile utilizing a spirally wound bimetal to sense the temperature of air which is drawn through an opening in the dashboard and through an ambient temperature compensating heat exchanger. The center of the spiral bimetal is supported by a shaft while the peripheral end of the bimetal coacts with an air bleed valve assembly which is connected to a vacuum pressure source and a vacuum motor to position an air damper for producing desirable air temperatures in the passenger compartment. The air bleed valve is movable with respect to the bimetal in response to settings of a dash mounted control adapted to be manually set for a temperature desired in the passenger compartment. A feedback mechanism which operates in correspondence to the position of the damper rotates the interconnected shaft and bimetal to re-establish a desirable spacial relationship between the end of the bimetal and the air bleed valve assembly after a setting change of the control assembly.