Torque adjustment tool

A torque adjustment tool has an inner tube having a front tuning handle on the screw assembly, a spring, an upper toothed block, a lower toothed block, a plurality of balls, a central axis and an adjusting unit. The upper toothed block has a through hole at the center, and there are multiple ball slots arranged in a ring shape on one end surface. The lower toothed block has a polygonal through hole at the center.

BACKGROUND OF INVENTION

Field of Invention

The present invention relates to a torque adjustment tool, and more particularly to a torque adjustment tool capable of preventing overload.

Description of Related Art

Currently, a conventional torque adjustment structure90, as shown inFIG.8andFIG.9, includes: an inner tube91, a front fine-tuning rod92, a spring93, an upper tooth block94, a lower tooth block95, a stopper96, a compression member97, a knob98and a linking member99. The inner tube91has a cylinder911at one end and a polygonal body912at the other. The cylinder911of the inner tube91is provided with an internal screw hole913, and the cylinder911has a fine-tuning fixing hole914connected to the inner screw hole913. The polygonal body912is provided with a chamber915with an internal screw thread section916at its inner wall, and a polygonal through hole917is provided between the chamber915of the inner tube91and the internal screw hole913. The polygonal body912of the inner tube91has a sliding slot918with a stop screw919at its inner wall, and the chute918is connected to the chamber915. The front fine-tuning rod92is installed at the front end of the inner tube91, an external thread section921is provided on the outer wall of the front fine-tuning rod92, and the front fine-tuning rod has a stepped through hole922. The spring93is disposed in the polygonal through hole917of the inner tube91and the stepped through hole922of the front fine-tuning rod92. The upper tooth block94is located in the chamber915and the polygonal through hole917of the inner tube91, and the upper tooth block94has a polygonal body in corresponding to the polygonal through hole917of the inner tube91. The upper tooth block94further has a through hole941, and one side of the upper tooth block94has a plurality of upper teeth942. One side of the upper tooth942is a vertical surface, and the other side is an inclined surface. The lower tooth block95is disposed in the chamber915of the inner tube91and engages with the upper tooth block94. The lower tooth block95has a polygonal through hole951and a plurality of lower latching teeth952, and one side of the lower tooth952is a vertical surface, and the other side is a inclined surface. The stopper96is installed in the chamber915of the inner tube91and located on one side of the lower tooth block95, and the stopper96has a through hole961and a screw hole962. The compression member97is located at the internal thread section916of the chamber915of the inner tube91, and the compression member97has a polygonal through hole971and an external thread segment972. The adjusting knob98is disposed at the rear end of the inner tube91and made of insulating material, and the adjusting knob98has a polygonal groove981and two inlays983opposite each other on the outer surface, and an polygonal groove984. The linkage member99is located in the polygonal groove984of the adjustment knob98, and the linkage member99has a polygonal slot991at one end and a polygonal connecting rod992at the other end.

However, the conventional structure as mentioned above still has the following problems: the upper tooth block94and the lower tooth block95utilize the upper teeth942and the lower tooth952for setting torque value, due to the stress-bearing area of the inclined surfaces of the upper latching tooth942and the lower latching tooth952is smaller, the transmission is less reliable. When the applied force is higher than the set torque value, the upper tooth block94and the lower tooth block95need to be separated from each other through tooth skipping and become in an idling state, but the friction resistance from the inclined surfaces is relatively large, the upper latching942and the lower teeth952are difficult to escape, such that the sensitivity of the overload protection is not enough.

Therefore, it is desirable to provide a torque adjustment tool to mitigate and/or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a torque adjustment tool capable of preventing overload.

In order to achieve the above mentioned objective, a torque adjustment tool has an inner tube having a front tuning handle on the screw assembly, a spring, an upper toothed block, a lower toothed block, a plurality of balls, a central axis and an adjusting unit. The upper toothed block has a through hole at the center, and there are multiple ball slots arranged in a ring shape on one end surface. The lower toothed block has a polygonal through hole at the center, tooth slots and multiple teeth.

Other objects, advantages, and novel features of invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

First, please refer toFIG.1andFIG.3. A torque adjustment tool comprises: an inner tube10, a front tuning handle20, a spring30, an upper toothed block40, a lower toothed block50, a plurality of balls60, a central axis70and a adjusting unit80. The inner tube10has an inner screw hole101at one end and a containing space102at another end. A first inner threaded section103and a second inner threaded section104are provided on a sidewall of the containing space102. The containing space102and the inner screw hole101are connected by a polygonal hole105, and a sidewall of the inner tube10has at least one a sliding slot106passing through the containing space102and having at least one screw11. The front tuning handle20has an open end and a closed end, the open end has an outer threaded section21on an outer surface for engaging with the inner screw hole101of the inner tube10, and the closed end has a through aperture22for accepting an external tool wrench A for insertion into the inner tube10. The spring30is disposed in the inner tube10, an end of the spring30abutting the closed end of the front tuning handle20. The upper toothed block40has a through hole41surrounded by a plurality of ball slots42. The upper toothed block40is disposed in the containing space102of the inner tube10and the polygonal hole105and abuts against another end of the spring30, and the upper toothed block40is shaped as a polygonal body corresponding to the polygonal hole105of the inner tube10. The lower toothed block50has a polygonal through hole5at a center position and a plurality of tooth slots52and a plurality of teeth53alternatingly at one end, the lower toothed block50is disposed in the containing space102of the inner tube10, and the lower toothed block50and the upper toothed block40are engaged via the balls60. The central axis70has a driving hole71with polygonal shape and is placed through the polygonal through hole51of the lower toothed block50and the through hole41of the upper toothed block40and the central axis70is sandwiched between the adjusting unit80and the lower toothed block50via the adjusting unit. The central axis70has a polygonal portion72corresponding to the polygonal through hole50. With the engagement of the polygonal portion72and the polygonal through hole51, the external tool wrench A inserted from the through aperture22further enters into the driving hole71, such that the lower toothed block50and the central axis70all move simultaneously, as shown inFIG.5andFIG.6. The adjusting unit80has a positioning ring81, a compressing member82and a stopping ring83. The positioning ring81has at least one screw hole811for accepting a screw in the containing space102to limiting the positioning ring81in the containing space102. The compressing member82and the stopping ring83respectively have a first outer threaded section821and a second outer threaded section831such that the compressing member82engages with the first outer threaded section821via the first inner threaded section103, the stopping ring83engages with the second inner threaded section831via the second outer threaded section104, and the compressing member82has a polygonal hole822.

Furthermore, the inner tube10has two sliding slots106, and the positioning ring81has two screw holes811.

Also, one of the sliding slots106has a screw11, and another sliding slot has106a screw11and an elastic plate.12.

Furthermore, the polygonal hole105and the upper toothed block40, the polygonal through hole51and the polygonal portion72respectively have matching hexagonal shapes.

Additionally, the driving hole71and the polygonal hole822both have hexagonal shapes.

Again, one sidewall of each tooth slot52is a vertical side and another side is an inclined side.

Moreover, a top end of each tooth53has a groove531for positioning the ball60to prevent the ball60from escaping between the lower toothed block50and the upper toothed block40, and the groove531connects the tooth slots52at both sides of the teeth53.

Also, the lower toothed block are separate parts as shown inFIG.2.

Additionally, the lower toothed block50and the central axis70are integrally formed as shown inFIG.7.

In actually operation, a polygonal wrench tool is inserted into the polygonal hole822of the compressing member82from the stopping ring83and rotated, as shown inFIG.4, so that with the engagement of the outer threaded section821and the first inner threaded section103, the compressing member82is able to be rotated inwardly or outwardly in the inner tube10. When the pre-set torque value is higher, the compressing member82is rotated inward and pushes the positioning ring81to move, the positioning ring81then pushes the lower toothed block50closer to the upper toothed block40, and the upper toothed block40is pushed by the elasticity of the spring30, so that the lower toothed block50and the upper toothed block40is more tightly locked with each other through the balls60, which generates larger torque value. When the pre-set torque value is lower, the compressing member82is moved outwardly, the positioning ring81, the lower toothed block50and the upper toothed block40are elastically pushed by the spring30and move outwardly. At this time, the lower toothed block50and the upper toothed block40are less tightly locked, and generated torque value is lower. When driving the tool wrench A to rotate, as shown inFIG.5, if the applied force exceeds the pre-set torque value, the balls60will be brought out of the tooth slot52to form an idling phenomenon, which allows the tooth slot52to rotate. The lower toothed block50and the upper toothed block40cannot be locked by the balls60, so the overload protection effect can be provided, as shown inFIG.6.

The above-mentioned torque adjustment tool has the following advantages: the outer circumferential arc surface of the steel60has a larger stress-bearing area relative to the inclined surface, so when the upper toothed block40and the lower toothed block50are locked by the balls60and it makes the transmission more reliable. Furthermore, with the rolling of the balls60, the friction resistance can be greatly reduced, which makes it easier for the steel ball60to be taken out of the tooth slot52for high overload protection sensitivity.