Abstract: A parking brake apparatus including a bolt screw rotated by a driving force transmitted from an actuator, one or more pistons disposed at one side or both sides of the bolt screw, one or more screw nuts accommodated in the piston, screwed to an end of the bolt screw, and moved along with the rotation of the bolt screw, one or more elastic members disposed around the screw nut within the piston, and elastically deformed, in response to a displacement of the screw nut while the screw nut is moved by a set distance, to press the piston toward a shoe, and a load transfer unit disposed in the piston, and configured to transmit, to the piston, a displacement of the screw nut when the screw nut moves more than the set distance, thereby pressing the piston toward the shoe.

Abstract: The present disclosure relates to an organic electroluminescent compound, a plurality of host materials, and an organic electroluminescent device comprising the same. By comprising the organic electroluminescent compound according to the present disclosure or by comprising a specific combination of compounds according to the present disclosure as a plurality of host materials, it is possible to produce an organic electroluminescent device having improved luminous efficiency, and/or lifetime properties compared to the conventional organic electroluminescent devices.

Abstract: The present disclosure relates to a printed circuit board and a method of manufacturing the same. The printed circuit board includes: an insulating layer; a plurality of pads disposed on the insulating layer; and a plurality of insulating walls that are disposed on the insulating layer and cover side surfaces of the plurality of pads, respectively, but are not disposed on upper surfaces of the plurality of pads. The plurality of insulating walls are disposed to be spaced apart from each other on the first insulating layer.

Abstract: The present disclosure relates to an organic electroluminescent device. The organic electroluminescent device of the present disclosure shows high luminous efficiency and good lifespan by comprising a specific combination of the plural kinds of host compounds and a specific hole transport compound.

Abstract: The present invention relates to a multi-component host material and an organic electroluminescent device comprising the same. By comprising a specific combination of the multi-component host compounds, the organic electroluminescent device according to the present invention can provide high luminous efficiency and excellent lifespan characteristics.

Abstract: The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. The organic electroluminescent compound of the present disclosure may be comprised in a light-emitting layer, and is effective for producing an organic electroluminescent device having high luminescent efficiency and/or excellent lifespan characteristic.

Abstract: The present disclosure relates to an organic electroluminescent device. The organic electroluminescent device of the present disclosure shows high luminous efficiency and good lifespan by comprising a specific combination of the plural kinds of host compounds and a specific hole transport compound.

Abstract: The present disclosure relates to a rotation prevention member of a leg screw for fixing a bone that is configured to prevent rotation of a leg crew that is coupled to a nail in a medullary cavity such as a femur and fixes a fracture portion. The rotation prevention member of a leg screw for fixing a bone, in which a femoral nail is fitted in an end of a femoral marrow, a leg screw combined with a cap is laterally inserted in a transverse hole formed at an angle with respect to a longitudinal axis of the nail, and the leg screw is fixed to be longitudinally movable without rotating in the transverse hole, includes: pin guide grooves formed symmetric to each other in a longitudinal direction of the leg screw; a superelastic member inserted in the pin guide grooves; and a cap thread-fastened to a rear surface of the leg screw to prevent separation of the superelastic member in order to prevent rotation between a threaded portion of the leg screw and a bone due to rotation after a fracture part is occupied.

Abstract: The present disclosure relates to a surgical aiming device 1 that prevents a sleeve from being pushed backward or shaken when a drill or a leg screw is implanted after a guide sleeve is mounted on an aiming device. The surgical aiming device includes: a body 20 having an aiming arm 21 and a barrel 22; a guide sleeve 30 disposed at an end of the aiming arm 21 and guiding a nail 10 and a leg screw 12; and a knob 40 for detachably attaching the guide sleeve 30, in which the guide sleeve 30 can be detachably attached in a one-touch type by a guide sleeve attachment/detachment unit 100 installed at an end of the aiming arm. The guide sleeve attachment/detachment unit 100 includes: an operation unit 21a installed at an end of the aiming arm 21; a button 110 installed at the operation unit 21a and partially exposed to the outside; an operation lever 120 being rotated on a rotary shaft by operation of the button 110; and a threaded portion 30a controlled by the operation lever 120 and formed on the guide sleeve 30a.

Abstract: A roller shoe has a pliable bottom. Rear wheels are independently rotatable about a rear axle recessed in the heel portion. A front wheel is rotatable on a front axle recessed in the arch portion. Both axles are removably yet firmly supported partially recessed within wheel housings. Rolling with front and rear wheels on a flat skating surface holds the forward portion of the shoe bottom clear of the skating surface. Tilting forward onto the front wheel alone allows pivoting while rolling. Tilting farther forward brings the forward portion down to sliding, standing or walking contact with the skating surface. Tilting backward onto the rear wheels alone allows pivoting while rolling. Tilting backward in the extreme brings the shoe heel into sliding or resting contact with the skating surface. Wheels are formed of urethane, axles and bearings of steel, shoe of textile or leather, shoe bottom of resinous or rubber material, and wheel housings of strong plastic such as nylon.