Abstract: A directional coupler for coupling r.f. energy in a waveguide system from a main channel waveguide to a subsidiary channel waveguide, the coupling being in the range between about -3 dB to -15 dB. The coupler comprises a single coupling slot at the junction between the main channel waveguide and the subsidiary channel waveguide with an arrangement for decoupling the slot to yield the desired coupling, the arrangement including first and second posts in the plane of the junction. A further provision involves inductively loading the junction, the loading being provided at the plane of the junction. The provision for inductively loading the junction is an "inverted" button, in the form of capped-off holes, the depth of the holes being adjusted to vary the directivity of the coupler.

Abstract: An optical projection system has been provided which is particularly suited for use in microlithography and includes a source of exposure energy for generating a beam of energy. A primary lens and mirror are located in the path of the beam for receiving the beam and passing only a portion of the beam therethrough. A refractive lens group is located in the path of the portion of the beam for receiving and transmitting that portion. A recticle element is located in the path of the portion of the beam and has a uniform thickness having a pattern on one surface thereof and an unpatterned portion adjacent thereto. The reticle element is positioned for permitting the portion of the beam to pass through its thickness and for reflecting the portion of the beam back through its thickness and the refractive lens group to the primary lens and mirror.

Abstract: A technique and arrangement for lowering the mismatch normally obtained, thereby increasing the bandwidth, in a standard rectangular-to-coaxial waveguide "T" junction coupling in an antenna system, such arrangement including, in a T-junction of a coaxial transmission line to a waveguide transmission line in which measured impedance values in the range of approximate 30 MHz in the UHF band must be within a 1.1:1 circle of voltage standing wave ratio, the improvement which achieves minimal reflection over said range of frequencies, according to which a diconical slug is connected between an upper and lower portion of the coaxial transmission line and mounted for support within the structure of the waveguide transmission line, and in which said diconical slug includes back-to-back conical sections such that the large diameter rims of the sections confront each other.

Abstract: Method and apparatus for loading and unloading semitrailers on a train of flat cars by coupling the semitrailers to power driven stanchions respectively, providing the power driven stanchions with automatic control in the form of proximity sensors for governing movement of the semitrailers in accordance with proximity of adjoining semitrailers and automatically steering the stanchions along a guide path to load and unload the train.

Abstract: A suppression control device comprises a relay valve together with respective temporary and permanent diaphragm operated circuit breakers for governing suppression of a cab signal penalty brake application that can be used with either of two principal types of locomotive braking systems as well as being adapted to automatically adjust to changes in brake pipe pressure settings of 90 psi and 110 psi.

Abstract: An arrangement for conserving the alarm-state power supplied to numbers of light emitting devices included in respective addressable terminal units of a fire alarm system or the like. The addressable terminal units are connected to a transmission line or loop; and a loop controller cyclically transmits address signals to the terminal units (polling routine); the controller functions, responsive to received data from those units, to generate an alarm-state display command signal for causing illumination of the light emitting devices of terminal units that are in alarm. In the case where a terminal unit comprises a master transponder to which a group of non-addressable conventional "slave" detectors is connected, the loop controller is programmed to disconnect such slave detector from the loop or line when more than one of them is in alarm. However, in the event of a large number of terminal units at scattered locations being in alarm, a tell-tale signal from each unit is highly desirable.

Abstract: An environmental monitoring system in which a controller is arranged to test the workability and reliability of a plurality of detector units on a cyclic basis. Each unit has an analog sensor and an analog to digital converter for converting the analog sensor voltage to a digital value in a range of 0 to N. Each unit responds to a test instruction to cause the sensor analog output to assume an alarm value. The sensor output is limited to a maximum value that under a no drift condition of the analog to digital converter, its corresponding digital signal value will be intermediate a tolerance range of values, the upper limit of such range being less than N. The controller includes a test routine program for both issuing the test instruction and for determining if the digital signal test value is within the tolerance range and issuing a trouble output indicative of the test value being outside the range.

Abstract: Improvement to a fire alarm system that enables a city tie line connection to be made selectively. Terminal units at a variety of locations are coupled or connected in separate, independent loops within the system such that serial synchronous power transmission and data communication is effectuated over the individual loops. A master controller at a central location is programmed to recognize that certain terminal units connected in particular loops of the system are in alarm states and to cause a city tie line connection to be made, selectively, whereby a municipal fire department or the like is informed of the particularly critical alarms emanating from those terminal units.

Abstract: The invention provides an electronic horn for an alarm circuits of the type in which the d.c. power supply for the horn will be of a particular polarity to indicate an alarm condition. The circuit provides a piezo sounder connected across the terminals of the power supply, an inductor connected in parallel with the piezo sounder to form a tank circuit therewith and current modifying means connected in series with the tank circuit to modify the current through the tank circuit in response to the output of an R/S flip-flop which is periodically set by a clock signal at a frequency corresponding to the frequency desired for the fundamental audible tones of the sounder. The duration of the clock output pulse which makes the modifying means conductive must be such that the capacitance of the sounder is charged by the supply before the output of the clock permits a change of state in the flip-flop to make the modifying means nonconductive.

Abstract: A fire alarm system in which a large number of terminal units, comprising detectors and interface circuits, at a variety of locations are coupled or connected in separate, independent loops of the system, each of the scattered terminal units being addressable from a central control panel. The arrangement is such that serial synchronous power transmission and data communication is effectuated over the individual loops of the system. The improvement resides in providing continuity-isolation testing for a Class A wiring scheme involved in the loops. By Class A operation is meant that there are two separate channels involved in each loop. A continuity test is sequentially performed on both channels of the loop such that discontinuities can be precisely located.

Abstract: A strobe light circuit is provided for flashing a strobe flash unit at a desired frequency. An inductor is repetitively connected and disconnected across a d.c. power line by a switch means so that energy is stored in the inductor during the period when the circuit is complete. The flash unit and a capacitor are connected in parallel so that the capacitor can discharge its stored energy to the flash unit when the voltage across the capacitor exceeds the threshold firing voltage of the flash unit. The parallel combination of the flash unit and the capacitor is in turn connected in series with a diode, and the resulting series circuit is connected across the inductor with the diode being connected in polarity such that current will not flow from the power line through the flash unit or the capacitor.

Abstract: A broadcast switching system includes at least two sources, such as power amplifiers or transmitters; a waste or dummy load; and an antenna. A non-contacting switching arrangement for such a system includes directional or hybrid couplers for suitably cross-coupling portions of the signals from each of the sources. The present system is such that at least two couplers of nominally identical value may be employed regardless of input power ratios and yet, required power levels can be obtained at the outputs by reason of the deployment of phase shifters providing controlled phase delays over the entire range, which phase delays are precisely selectable for a full range of input power ratios. Although a nominal coupling value of -3 dB for the couplers may be utilized, the invention is not necessarily restricted to this value.

Abstract: In an electronic horn for alarm systems of the type in which an alarm condition is indicated by a reversal of polarity in the d.c. power supply, an improvement provides a pair of terminals for connection to said d.c.

Abstract: In the manufacture of ductile iron it is important to know that the magnesium content is above (or possibly below) a threshold value. It is known that the presence of magnesium prevents tellurium causing solidification of a sample with carbidic eutectic arrest. Accordingly we treat a sample in a receptacle with a known quantity of sulphur (or selenium) such as just to neutralize the threshold quantity of magnesium, then we observe whether, on solidification, the eutectic arrest is graphitic (indicating that more than the threshold quantity of magnesium is present) or carbidic, indicating less magnesium. The observation is most simply done (and can be done semi-automatically) by timing a cooling curve between two predetermined temperatures.

Abstract: A spring hanger system for supporting a rectangular waveguide on a transmission tower or other structure, including a plurality of vertically spaced spring hangers, each adapted to engage and support a section in the vertical run of the waveguide. Each hanger includes (1) a lateral support guide for restraining the guide from any appreciable movement in all directions except vertical, and adapted for fixation to the supporting structure; (2) a gripping frame adapted to grip tightly the outer periphery of the waveguide without seriously deforming same, the gripping frame being spaced vertically below the lateral support guide; and (3) a relatively constant force spring mechanism connecting said gripping frame to said lateral support guide, thus allowing the waveguide to move upwardly and downwardly with variations in temperature without substantially changing the top loading on the tower.

Abstract: A specially designed, Z-shaped, parasitic dipole is spaced radially outwardly from the slot provided in a cylindrical antenna; a controlled amount of energy which is in a horizontally polarized direction is coupled to the Z-shaped dipole so as to radiate energy into the vertical plane, thus creating a variable circularly polarized antenna capable of adding a selectable amount of vertical component to the horizontal in quadrature; since the dipole element, which parasitically develops its polarized energy, is in the same horizontal plane as the polarized energy emanating from the slot, a good, i.e. constant, axial ratio is maintained throughout the elevation pattern.

Abstract: Coupler control system for railway vehicles that provides isolation of the electric and pneumatic lines of a rail vehicle from its corresponding electric and/or pneumatic intervehicle interface when that end of the vehicle is in an uncoupled condition. A combination proximity sensor and switch is positioned within the mechanical hook coupling housing so as to sense the actual engagement of the mechanical hooks of a pair of vehicles. The switch then closes and becomes operative to initiate a coupling cycle during which the onboard electric and pneumatic lines are coupled to the associated electric and pneumatic interfaces to provide continuity with the vehicle to which it is coupled. Included in the circuitry for the sensor switch is a diode circuit arranged to permit looping of the sensor switch output across the electric interface onto the adjacent car and back through the interface through the use of only two interface connector pins per interface.

Abstract: A broadcasting arrangement includes a source of signals to be transmitted which is subject to distortion in the event that signals are reflected. An antenna is adapted for radiating all the signal applied to a polarization sensitive input part with a particular polarization. The antenna is mounted on a tower. A waveguide is coupled to the source of signals and to the input port of the antenna. If the waveguide is circular waveguide, the windload on the tower due to wind loading of the circular waveguide is low, but flexure which occurs results in polarization changes which causes signals applied to the antenna input port to be reflected, thereby reducing radiated power and causing distortion. If the waveguide is rectangular, the wind loading is high and the tower must be more sturdy and therefore more costly than for circualr waveguide. A truncated circular waveguide is used which has a wave propagation channel defined by a cylinder and a pair of parallel longitudinal plates in the cylinder.

Abstract: A fluid brake system has a brake pipe, a control valve device, a brake cylinder and a brake rigging, and in addition, a handbrake pipe, a protective device, a fluid pressure releasable spring handbrake cylinder, and a manually operable handbrake device for selectively governing brakes of the brake rigging under varying conditions, as when air supply is disconnected from a train. A moveable fulcrum in the manual handbrake device permits manual release of spring applied handbrakes in combination with a resetable toggle locking connection to a handbrake rod.

Abstract: A retaining apparatus for retaining an associated wire includes a first slot having a width that is substantially the same as the wire, including any insulation, that is to be retained. The first slot is dimensioned for snug engagement with the associated wire. A second slot intersects the first slot. The second slot has walls at least in some portion in the slot which have an interference with the associated wire to be retained.