Abstract: A speed change system for work vehicle having a continuously variable transmission device selects a first change gear ratio which is set larger than a smallest change gear ratio, when an engine rotational speed is a first set rotational speed which is set equal or close to an idling rotational speed of an engine; retains the change gear ratio of the continuously variable transmission device at the smallest change gear ratio, when the engine rotational speed is equal to or above a second set rotational speed set on a high-speed side relative to the first set rotational speed; and makes the change gear ratio of the continuously variable transmission device larger between the first change gear ratio and the smallest change gear ratio, as the engine rotational speed at that moment becomes lower, when the engine rotational speed is between the first and second set rotational speeds.

Abstract: A PTO control system for allowing selection between an independent PTO mode and an interlock PTO mode, comprising a mode-switch command input device 11 for giving an instruction on selection between the independent PTO mode and the interlock PTO mode, a PTO setting device 12 having an engaging position for producing an engaging command and a disengaging position for producing a disengaging command of the PTO clutch, and a PTO control unit for controlling a PTO clutch in response to a pedal operational position of a brake pedal, a mode selected by the mode-switch command input device, and a position selected by the PTO setting device. PTO mode switch implementation processing is suspended when the PTO transmission system is in a power transmittable state, while the PTO mode switch implementation processing is permitted when the PTO transmission system is in the power non-transmittable state.

Abstract: A transmission device for a work vehicle, comprising a travel drive system for transmitting engine power to a travel device; an implement drive system for transmitting engine power to an external power take-off shaft; braking operation tools for a braking operation; a stop operation mechanism provided to the travel drive system and capable of interrupting the transmission of power to the travel device; and a hydraulically operated PTO clutch for interrupting the transmission of power to the external power take-off shaft, the PTO shaft being provided to the implement drive system; wherein the stop operation mechanism and the PTO clutch are linked with the braking operation tools so that the stop operation mechanism is operated to a power transmission stopping position and the PTO clutch is disengaged along with a pressing operation of the braking operation tools, and the PTO clutch is engaged along with a press-releasing operation of the braking operation tools; and an operation timing is set so that the PT

Abstract: A travel operation structure of a work vehicle, comprising a pair of left and right side brake pedals disposed on either the left or right of a steering wheel; a hydro static transmission for changing the speed of travel; and a stop operation pedal disposed on the other of the left and right of the steering wheel; wherein the corresponding left or right side brake is applied when one of the pair of left and right side brake pedals is depressed, and when both the left and right side brake pedals are depressed, both the left and right side brakes operate, and travel is stopped; and when the stop operation pedal is depressed, operating oil of the continuously variable speed change device is directed into an oil tank, and the continuously variable speed change device is switched to a neutral stop position for blocking transmission of power to the travel device.

Abstract: A transmission control apparatus includes transmission lines disposed between a pair of transmission shafts and a hydraulic multiple disc transmission clutch disposed on one side of the transmission lines. Power from an engine is transmitted via one of the transmission lines to a traveling unit. Each of the transmission lines has a friction clutch. A first gear mechanism operated by a first actuator is disposed between one of the transmission shafts and the first transmission line. A second gear mechanism operated by a second actuator is disposed between one of the transmission shafts and the second transmission line. When the first transmission line is powered, a first system operates the second gear mechanism into a speed position; the first clutch to a non-transmitting state and the second clutch to a transmitting state, thereby providing a progressive shifting of the transmission clutch from a transmitting state to a semi-transmitting state.

Abstract: A control apparatus (64) for a transmission.

Abstract: A radiation-sensitive composition is described, which is comprised of (1) a polymer containing repeating units of the formula: ##STR1## wherein R.sup.1 is a trivalent or tetravalent aromatic or heteroaromatic residue having 6 to 30 carbon atoms, R.sup.2 is a divalent aromatic or heteroaromatic residue having 6 to 30 carbon atoms, R.sup.3 is hydrogen or an ammonium ion, n is 1 or 2, and COOR.sup.3 is located in an ortho or peri position with respect to the amide linkage, (2) an organic compound having a radiation-dimerizable or radiation-polymerizable olefinic double bond and an amino radical or a quaternary ammonium salt, and (3) an aromatic monoazide compound [III] having no substituent or having a neutral or acidic substituent. This composition has a highly improved radiation sensitivity and the sensitive wavelength region of this composition is very broad. This composition can give a highly heat-resistant relief pattern with a good edge sharpness.

Abstract: A radiation-sensitive composition is described, which is comprised of (1) a polymer containing repeating units of the formula: ##STR1## wherein R.sup.1 is a trivalent or tetravalent aromatic or heteroaromatic residue having 6 to 30 carbon atoms, R.sup.2 is a divalent aromatic or heteroaromatic residue having 6 to 30 carbon atoms, R.sup.3 is hydrogen or an ammonium ion, n is 1 or 2, and COOR.sup.3 is located in an ortho or peri position with respect to the amide linkage, (2) an organic compound having a radiation-dimerizable or radiation-polymerizable olefinic double bond and an amino radical or a quaternary ammonium salt, and (3) an aromatic secondary or tertiary amine compound which is chemically inactive to actinic radiation. This composition has an improved photo-sensitivity or radiation sensitivity and can give highly heat-resistant relief patterns with a good edge sharpness and good mechanical and chemical properties as well as good insulating properties.