Abstract: Disclosed is a dental handpiece structure including a head having a turbine chamber, a rotor installed in the turbine chamber and having a transmission shaft, and a transmission element composed of a plurality of turbine vanes. A high-pressure air entering into the turbine chamber can push each turbine vane to drive and rotate the rotor, and a breach is upwardly formed between two adjacent turbine vanes. A head cap is covered onto the turbine chamber, and a circular groove is formed at the head cap and between an end surface facing the turbine chamber and the transmission element, and the circular groove and each breach are arranged opposite to each other for collecting the high-pressure air guided out from each breach to enhance the cutting force of the dental handpiece.

Abstract: Disclosed is a dental handpiece structure including a head having a turbine chamber, a rotor installed in the turbine chamber and having a transmission shaft, and a transmission element composed of a plurality of turbine vanes. A high-pressure air entering into the turbine chamber can push each turbine vane to drive and rotate the rotor, and a breach is upwardly formed between two adjacent turbine vanes. A head cap is covered onto the turbine chamber, and a circular groove is formed at the head cap and between an end surface facing the turbine chamber and the transmission element, and the circular groove and each breach are arranged opposite to each other for collecting the high-pressure air guided out from each breach to enhance the cutting force of the dental hand-piece.

Abstract: A motor spindle fixture includes a fixing base, a motor and a casing. The motor includes a main body and a spindle penetrating through the main body and protruding from both ends of the main body. The spindle has an end defined as a driving end for driving an external device and another end defined as a fixing end. The motor is pivotally mounted onto the fixing base through the driving end of the spindle. The casing is mounted onto the fixing base and has an accommodating space for accommodating the motor, and a chamber concavely formed on a sidewall of the casing and corresponding to the fixing end of the spindle. The chamber includes a fixing element, and the fixing end of the spindle is extended into the chamber and pivotally coupled to the fixing element for fixing the spindle, and preventing the spindle from being damaged by external impact forces during the operation of the motor.

Abstract: A remote-control helicopter rotor mechanism includes a rotor with multiple blade-root attachments and each blade-root attachment includes a slot located between two arms. Each arm includes two clamping surfaces and a recess which is defined longitudinally in an inside thereof and located between the two clamping surfaces. Multiple blades each have an elongate body and a root, the root has two protrusions extending from two opposite sides thereof and a passage is defined through the two protrusions and the root. The root inserted into the slot of the blade-root attachment corresponding thereto and a screw extends through the two arms and the passage of the root to connect the root within the slot. The protrusions are matched with the recesses of the two arms and the two clamping surfaces are matched with surfaces of the root.

Abstract: A press-type bit-holding mechanism of a dental high-speed handset, including a hollow rotary shaft, a push button accommodated in the hollow rotary shaft and a holder barrel also accommodated in the hollow rotary shaft. The push button has a first coupling section formed with two opposite splits and two opposite first projecting posts. The first projecting posts and the splits are interlaced with each other. The holder barrel has a second coupling section has two second splits and two second projecting posts complementary to the first splits and the first projecting posts of the first coupling section of the first coupling section of the push button.

Abstract: A remote controller has a body and a seat. A holding portion is between the body and the seat for being held by a hand of a user. The body is installed with a trigger and a rotary wheel for being held and operated by two hands of the user. The trigger is installed at an intersection of the body and the holding portion. The rotary wheel is installed on the body facing toward a lateral surface of the user. An angle is formed between an axial line of the rotary wheel and a moving direction of the trigger, wherein the angle is larger than 90 degrees.

Abstract: A mold and method for producing a two-stroke engine casing of a radio control model are to define a core cavity and a main cavity in the mold. A first core has a first end inserted into the mold and the core cavity is defined around the first end of the first core for forming a core and simplifying the manufacturing processes. The first core with the core is inserted into the main cavity to from the cylinder of the engine and the blocks of the core define grooves in the inner periphery of the cylinder of the engine.

Abstract: A forward/backward switch protective structure for a remotely controllable car, including an output shaft having a differential section. Two gears are respectively rotatably disposed at two ends of the differential section. A seat body is fixedly disposed on the differential section and a shade body is fitted on the differential section. The shade body is formed with a differential engaging hole for the differential section to fit therethrough. A shade body is controlled by a shifting mechanism and movable along the differential section. The shade body is formed with an internal chamber for receiving therein the seat body. The chamber is formed with annular grooves. When the engaging sections of the shade body are respectively engaged with the stop sections of the gears, the annular grooves respectively correspond to the throw plates of the seat body. When outward centrifugally extended, the throw plates are inserted into the annular grooves to prevent the shade body from moving.

Abstract: A structure for quickly turning up a car shell of a remotely controllable car, including two fixing boards connected with the car body for fixing the car shell. Each fixing board has a projecting column having a stop section at top end. The car shell is formed with a through hole for the column and the stop section to pass therethrough. A seat body is disposed on inner face of the car shell. A clip disposed on outer face of the car shell is connected with the seat body. The clip has a clip section and a press section. The clip section clips the column of the fixing board and is stopped by the stop section to fix the car shell. When turning up the car shell, the press section is compressed to stretch open the clip section and release the clip section from the stop of the stop section. Then the press section of the clip can be lifted to turn up the car shell.

Abstract: A structure for connecting a rim with a tire. The tire is formed with a central axial through hole. Multiple annularly arranged perforations are formed around the through hole. Each perforation is defined by a close circumference which is separated from the through hole by a separating section, whereby the circumference of the perforation is enclosed and the perforation simply axially passes through the tire. The rim is composed of a seat and a cooperative disc. The seat has insertion members respectively corresponding to the perforations of the tire. The insertion members are inserted into the perforations from one side of the tire, while the disc is mounted on the other side of the tire to connect with the seat.

Abstract: An assembling structure for tail wing of a model airplane. The airplane body has a horizontal connecting face at tail section for connecting with the horizontal tail wing and vertical tail fin. A bottom face of the vertical tail fin is disposed with two projecting fixing rods. A center of the horizontal tail wing is formed with two through holes corresponding to the fixing rods of the tail fin. A sleeve is fitted on inner wall of each through hole. The connecting face of the tail of the airplane body is also formed with two through holes corresponding to the fixing rods of the tail fin. A sleeve is fitted on inner wall of each through hole. The fixing rods of the tail fin can be firmly passed through the tail wing and airplane body and locked by screws. Therefore, the tail wing of the model airplane can be quickly firmly assembled or disassembled from the airplane body for easy carriage or storage.

Abstract: An assembling structure for landing gear of a model airplane, including an airplane body having a base board on which a landing gear fixing seat mounted. The landing gear is fixed on the fixing seat by fixing pins passing through the fixing seat. The cap section of the fixing pin can be rotated by 90 degrees to engage in a channel of the fixing section of the landing gear. Under such circumstance, the landing gear is disengaged from the cap section of the fixing pin and can be quickly disassembled from the fixing seat and separated from the airplane body. Accordingly, the model airplane body and the landing gear can be quickly assembled and disassembled to facilitate carriage and storage of the model airplane.