Showing papers on "Beam (nautical) published in 1988"

Kayak safety sponsons

Abstract: Kayak safety sponsons having two parallel inflatable tubes along the waterline on each side of the kayak adjacent the cockpit. These tubes join together below the waterline by means of material such as straps and above the waterline at both ends by a fastener such as a strap with a quick-release buckle, at each end of the cockpit. They can be attached and inflated by the kayaker seated in the cockpit while using a paddle. Deflated, the sponsons are flat and tightly drawn against the hull by the two fasteners for minimal water resistance. Inflated, the sponsons taper toward both ends for minimal water resistance, increasing maximum waterline beam of the kayak adjacent to the cockpit area but not affecting foreward and aft lines of the craft, permitting normal handling due to minimal change in underwaterlines and minimal increase in water resistance.

Flotation body for ships

Abstract: In vehicle ferries that are loaded by the roll-on/roll-off method, a loading unfavourable for the transverse stability results from the fact that the payload and the holds needed for it lie above the waterline. In known ship forms, enlarging the beam to increase the stability is limited by the resulting increase in the resistance. The function of the invention is to design the flotation body so that good safety against capsizing, low resistance to propulsion in the case of a large beam, and the abilities to load and unload quickly, and to go ahead and astern, are achieved. This is achieved by a flotation body with a rectangular outline, together with a water channel running through the middle thereof, thus dividing the flotation body into two partial flotation bodies that provide the buoyancy. The water channel is closed off at the top and bottom.

Reflection type photoelectric sensor

Abstract: PURPOSE:To easily adjust the converging position of projected beam, by providing a projected beam converging point position adjusting means moving a beam projecting optical system from the outside of a case. CONSTITUTION:This photoelectric sensor consists of the semiconductor laser 1, PSD 2, beam projecting lens 3 and beam receiving lens 4 received in a case consisting of a case main body 115 and a lid, and an adjustment knob 20 made freely rotatable is fitted to the main body 15. When the knob 20 is rotated, the distance between the laser 1 and the lens 3 is changed to make it possible to change the converging point position of projected beam alpha. At this time, since the knob part 201 of the knob 20 protrudes to the outside of the case and the knob 20 can be rotated from the outside of the case, the converging point position of the projected beam alpha can be easily adjusted from the outside of the case. Therefore, it is unnecessary to disassemble the main body 15 in order to adjust a position and positional adjustment can be performed with good accuracy.

Flotage preventer for earthquake-proof structure

Abstract: PURPOSE: To secure such a device that purely restricts only vertical displacement without entailing any damage to an earthquake-proof effect at the time of floatage of a superstructure by engaging an engaged beam locked to the superstructure with a restricted beam locked to a substructure. CONSTITUTION: A device A consists of an engaged beam 1 being locked to a superstructure B1 and a restricted beam 2 being locked to a substructure B2. The engaged beam 1 keeps a distance from a lower surface of the superstructure B1, and it is fixed to a part of a steel frame F1 assembled in a rectangle by having this part of the steel frame embedded in the superstructure B1 or the like and then installed horizontally. Likewise the restricted beam 2 keeps a distance in a gap with a top surface of the substructure B2, and it is horizontally installed at the upper side of the engaged beam 1 as crossed with it. A clearance C is installed between a top surface of the engaged beam 1 and a bottom surface of the restricted beam 2, through which an amount of flotage of the superstructure B1 is restricted. COPYRIGHT: (C)1990,JPO&Japio

Distance and angle-of-inclination measuring device

Abstract: PURPOSE:To detect the relative distance interval between a processing tool and an object to be measured or the positions and shapes or the like thereof in a noncontact state, by providing light projecting and receiving systems as one set and moving the same to obtain the min three arbitrary sets of light projection and receiving data on the surface of the object to be measured CONSTITUTION:The position where beam spot 6 is allowed to irradiate the surface 2 of an object to be measured from the stationary position of a sensor part 1 by a light projecting system is set to a start point and the projection quantity of beam of a laser diode 4 is adjusted by an emission controller 14 to project beam through a projection lens 5 The reflected beam forms a focus on a photodetector PSD 8 by a beam receiving lens 7 The PSD 8 generates the signal relating to the distance from the predetermined position of the sensor part 1 to the beam spot 6 and said signal is sent to a signal converter 9 and a relative distance is operated by a projection distance operation part 16 A distance and angle-of-inclination operation part 18 calculates the distance D between predetermined position of the sensing part and the surface 2 to be measured and the angles thetaX, thetaY of inclination of the plane crossing the rotary shaft of the sensor part 1 and the surface of the object to be measured

Method for measuring depth and width

Abstract: PURPOSE:To automatically measure the depth and width of a fine pattern rapidly and accurately in a non-contact state, by simple constitution such that the fine spot beam is projected to an article to be measured to form the projected part thereof into an image on the surface of a photoelectric converter element and the article to be measured is moved while the moving quantity thereof is detected by a linear encoder to measure the depth of the fine pattern. CONSTITUTION:An optical system 21 wherein fine laser spot beam is projected to an article 6 to be measured and the projected part thereof is formed into an image on the surface of a photoelectric converter element through a half mirror is moved by a Y-axis direction moving mechanism 22. Then, the depth of the article 6 to be measured corresponding to photoelectrically coverted max. output beam based on the focus matching image to the projected part of the spot beam is measured by a measuring and control circuit 26 through a linear encoder 23 for detecting moving quantity in a Y-direction. In the same way, the depth of each point is measured by moving the article 6 to be measured by an X-axis direction moving mechanism 24 while the moving quantity thereof is detected by a linear encoder 25 for moving quantity thereof is detected by a linear encoder 25 for detecting moving quantity in an X-direction and, by this simple constitution, the depth and width of a fine pattern can be automatically measured rapidly and accurately in a non-contact state.

Rotatable radar reflector partic for small ship

Abstract: The reflector is supported by a rotatable shaft to the end of which are fixed three edge-adjusted plates arranged at right-angles to each other, and connected to a horizontal plate. The reflector rotates in an anti-clockwise direction, and is enclosed in a protective casing, which is removable. The three plates are of highly reflective metal. Where the reflector is located on a small ship on the surface of the water, it works in conjunction with the radar antenna fitted at a much higher level on a large vessel. The radar transmitter emits a forwardly directed lobe, providing the strongest radar field apparently at a level above the reflector. This means that the radiation only comes into contact with the reflector with its lowest lobe part which has low strength. This part of the radiation is picked up by the top side of one of the three plates (4), reflected to the upper part of another plate, and is then given out as a reflected beam forming an echo signal.

Handscanner capable of varying scan width

Abstract: PURPOSE:To enable a bar code label having long length or plural bar code labels arranged adjacently to each other to be read with one scanner respectively, by enabling the scan width of a scanning beam to be adjusted. CONSTITUTION:A beam generating from a beam generating source is reflected on a rotary mirror 24 in an optical system 22, then being radiated to the outside, and scans an object (bar code) in directions of A and B, and a scan width adjusting mechanism 23 adjusts the size of the scan width in the middle way of the optical path of the beam. An adjustment in a rotary mirror system is performed in such way that the aperture quantity of the aperture part 26a of a slit sheet 26 on an optical axis is adjusted. In other words, the size of the scan width of the scanning beam is adjusted by setting the position of the slit sheet 26 at an appropriate level. In such way, it is possible to surely read the bar codes having various kinds of sizes, and arranged in a various ways.

Stable bed on ship

Abstract: The utility model discloses a stable bed on ship which uses reverse-swing compensation controlled by electricity The utility model is characterized in that the reverse-swing frame bearing a bed frame can swing relatively to a swing beam; the swing beam can also swing relatively to the bed bearing fixed to cabin with the help of an orthogonal swing shaft The reverse-swing compensation is performed by an electric control system which directs two servo motors fixed on the reverse-swing frame and bed bearing respectively to drive both reverse-swing frame relatively to the swing beam and swing beam relatively to the bed bearing for generating a reverse-swing rotary angle opposite to the swing direction of ship Thus, the bed frame can reach the assumption of maintaining the level state permanently during the swing of ship

The effect of ship motion on ship magnetic signature

Abstract: : The effects of roll, pitch and yaw motions on a ship's magnetic signature are investigated. These three modes of rotary motion, each simple harmonic, are treated as uncoupled and a dipole model representation is used to describe the ship's magnetization. Signatures are computed for a model ship assumed, for simplicity, to be bearing due magnetic North and compared with the steady-state signatures (for no rotary motion). Oscillatory magnetic field components result from these ship motions which decrease in significance, compared to the steady-state fields, as the observation point is moved further away from the ship's passage. These field deviations decrease more rapidly with a beam displacement than with depth. Variation with ship speed is more complicated and depends critically on the values assigned for the amplitudes, frequencies, and relative phases of the three modes of motion. In high sea states the magnetic signatures can vary considerably from those in calm seas with implications for magnetic-influence mine actuation. Keywords: Ship signatures; Magnetic signatures; Sea state; Australia; Ship motion.

Tool and method for milking animal

Abstract: PURPOSE: To provide an implement, with which a cup for test can be linked to the teat of the breast of an animal, equipped with a robot arm for holding the cup for teat to be applied and a means for individually positioning the respective cups for teat at the teats. CONSTITUTION: When a milking cow is taken into a milking room surrounded with fences 2, a sensor system 5 turns toward its rear side. An almost vertical frame beam 6 is arranged on the lateral side of the milking room, a lengthwise guiding means is formed at its upper end, and a robot arm 7 is attached near its lower end. The frame beam 6 is always held at a position suitable for the animal by a control mechanism 27. The robot arm 7 can be slid in heightwise direction to the frame beam 6 and is linked to a frame 47 attached to a slide block 45 so as to be turned around an almost vertical pivot pin. The robot arm 7 is composed of a 2nd section 54 linked to a 1st section 53 so as to be turned around the pivot pin.

The experiments on the sailing performance of the sail training ship nippon maru

Abstract: The NIPPON MARU, 2650 ton 4-masted bark, was built in 1984 to replace the former NIPPON MARU as a sail training ship for the cadets of Institute for Sea Training, Ministry of Transport, Japan. The authors have carried out the experiments to measure her sailing speed, leeway, apparent wind direction and speed and others in trade-wind zone of the North Pacific Ocean. In analysing this experimental data, they obtained ship speed/true wind speed ratios for each trim angle of yards and sail condition. Secondly, they obtained aerodynamic coefficients of her sails, by solving the equilibrium equations in steady sailing conditions. The results are as follows. In respect of ship manoeuvring, she made a speed of more than 75% of true wind speed in close-hauled under full sail, when her propellers were revolving freely. Staysails were effective when she sailed in the range from close-hauled to beam reach condition. In following wind condition she made a speed of 20% of the true wind speed under fore and aft sails only. In respect of aerodynamic performance, her sails stalled at 25Deg. of the attack angle and had a considerably larger lift and drag force than those by wind tunnel test. Her thrust force coefficient was maximum at close-reaching because of no interference of the aft sails to the fore sails, and thrust force mainly depended on her sail area.

Height measuring method for structure or the like under water

Abstract: PURPOSE:To eliminate the influence of oscillation of a ship by extending a cord body fixed to an underwater structure to a pulley fitted to an on-ship support rack and fitting a reflecting prism for a light wave range distance meter to the vertical part of the cord body over the surface of water CONSTITUTION:The pulley 3 is fitted to the support rack 2 stood on the ship 1 and a piano wire 5 whose one end is coupled with an underwater beam 4 on the bottom surface of the sea is extended A weight 7 is coupled with the other end of the piano wire 5 and applied with a constant tensile force Further, the reflecting prism 6 is fitted to the vertical part of the piano wire 5 on the sea surface as a target for the light wave distance meter 8 This distance meter 8 collimates the prism 6 to find the oblique distance (d) between KL and TL and a perpendicular angle alpha, thereby finding the specific height difference h1 Then, the specific height difference h2 between the reverse surface of the underwater beam 4 and DL is found from this value h1 and known l1 and l2, and H and H1

Assistance system for the decking of aircraft having a stationary flight on a ship platform

Abstract: The aircraft 1 comprises means for emitting a conical light beam 14. The vessel 2 comprises photosensitive cells 6 materializing the trace of the beam on the vessel, which is an ellipse 17. Means determine the equation of ellipse 17 and, from it, deck-landing information which is displayed on a table 25.

Large Slow Drift of a Ship in Slightly Modulated Beam Seas

Abstract: The slow sway motion of a moored fore-and-aft symmetric ship in slightly modulated beam seas is discussed. The slow motion is associated with long waves. Depending on the speed of propagation, they may be decomposed into the locked, free and radiated long waves. Numerical examples are given for a Series 60 (CB= 0.6) ship in some different wave packets. Because of the restoring force developed by the mooring line, resonance may occur and the magnitude of the slow sway can be large. Real fluid effects are not included.