Abstract: A backlash-free double row roller cam transmission mechanism includes two passive wheels, two sets of rollers respectively pivotally arranged on the circular peripheral edges of the passive wheels, and a transmission camshaft with two opposite sides of a spiral protrusion respectively abutted against the two sets of rollers. Use the principle of oblique wedge adjustment to generate the reverse thrust of the rollers, thereby eliminating the backlash between the rollers and the spiral protrusion. All rollers can abut against the entire spiral protrusion to increase the structural rigidity and transmission load and prolong the service life. The design is conducive to achieving the cam self-locking function.

Abstract: A parking garage elevator system includes a frame including two front posts, two rear posts, two upper support members each interconnecting upper ends of the front and rear posts of the same side, two middle support members each interconnecting intermediate portions of the front and rear posts of the same side, and two cross braces each interconnecting front ends or rear ends of the upper support members; upper and lower automobile platforms; a power transmitting mechanism including first and second electric motors and two chains each for transferring power from the first electric motor to the upper automobile platform or from the second electric motor to the lower automobile platform; and a safety mechanism including four sets of two safety hooks and a plurality of restrain screws on the upper automobile platform or the lower automobile platform.

Abstract: A parking garage elevator system includes a frame including two front posts, two rear posts, two upper support members each interconnecting upper ends of the front and rear posts of the same side, two middle support members each interconnecting intermediate portions of the front and rear posts of the same side, and two cross braces each interconnecting front ends or rear ends of the upper support members; upper and lower automobile platforms; a power transmitting mechanism including first and second electric motors and two chains each for transferring power from the first electric motor to the upper automobile platform or from the second electric motor to the lower automobile platform; and a safety mechanism including four sets of two safety hooks and a plurality of restrain screws on the upper automobile platform or the lower automobile platform.

Abstract: A double row roller cam transmission mechanism with backlash adjustment means is disclosed to include two passive wheels respectively provided with rollers, a transmission shaft with a spiral protrusion, and an adjustment device set operable to adjust the relative position between the two passive wheels so that the rollers of the two passive wheels can be respectively and positively abutted against the two opposite surfaces of the spiral protrusion of the transmission shaft to eliminate the backlash between the rollers and the spiral protrusion and to increase structural rigidity and transmission load.

Abstract: A double row roller cam transmission mechanism with backlash adjustment means is disclosed to include two passive wheels respectively provided with rollers, a transmission shaft with a spiral protrusion, and an adjustment device set operable to adjust the relative position between the two passive wheels so that the rollers of the two passive wheels can be respectively and positively abutted against the two opposite surfaces of the spiral protrusion of the transmission shaft to eliminate the backlash between the rollers and the spiral protrusion and to increase structural rigidity and transmission load

Abstract: A vehicle parking apparatus includes two front stanchions and two rear stanchions all mounted on a base frame; a top support interconnecting the front stanchions and the rear stanchions; a platform having a rear end moveably secured to the rear stanchions, and two sides moveably secured to the front stanchions; and two elevating assemblies, each including a first pulley on an upper portion of one rear stanchion, a second pulley fixedly disposed on either side of the top support, a third pulley on either side of the platform, a fourth pulley fixedly disposed on a bottom of one rear stanchion, the fourth pulley being driven by a motor, and a rope having one end secured to the base frame, and the other end secured to the top support, the rope sequentially passing through the first pulley, the fourth pulley, the second pulley, and the third pulley.

Abstract: A vehicle parking apparatus includes two front stanchions and two rear stanchions all mounted on a base frame; a top support interconnecting the front stanchions and the rear stanchions; a platform having a rear end moveably secured to the rear stanchions, and two sides moveably secured to the front stanchions; and two elevating assemblies, each including a first pulley on an upper portion of one rear stanchion, a second pulley fixedly disposed on either side of the top support, a third pulley on either side of the platform, a fourth pulley fixedly disposed on a bottom of one rear stanchion, the fourth pulley being driven by a motor, and a rope having one end secured to the base frame, and the other end secured to the top support, the rope sequentially passing through the first pulley, the fourth pulley, the second pulley, and the third pulley.

Abstract: The present invention discloses a portable earphone-microphone type digital music player capable of playing MIC sounds and comprises two insert holes on a body of the digital music player, and the two insert holes are an earphone output hole and a microphone (Mic or Line-in) input hole, and a select switch and a signal sensitivity adjusting knob are provided for switching a play function of the microphone (Mic) or a recording function of the Line-in microphone, and adjusting the input of a sound volume of said microphone or Line-in. If the play function of the microphone is selected, the signal sensitivity adjusting knob can be used for adjusting the input sound volume of the microphone.