Patent Application
20090169336
1. Field of the Invention
The present invention relates generally to a locking device for outputting high torque and can be easily operated and released.
2. The Prior Arts
Most of conventional machine, especially for those including rotational parts such as grinding wheels, use bolts or nuts to lock the rotational parts. The bolts or nuts have to be tightened or loosened by tools such as wrenches or screwdrivers. The operation of the wrenches or screwdrivers take a lot of time and effort, and the users have to carry different types of sizes of the tools. This is inconvenient for the users.
A primary objective of the present invention is to provide a locking device which is easily operated without using tools and can quickly lock or unlock a rotational part.
The present invention is designed based on a planet gear system which includes an outer ring, balls and a locking disc. The outer ring performs as the ring gears on the outside of the planet gear system, the balls perform as the planet gears and the locking disc performs as the sun gear. When the outer ring is rotated in the first direction, the balls are moved with the outer ring and bring the locking disc to rotate in the same direction so as to lock the rotational part. When the outer ring is rotated in the second direction, the locking disc can be quickly released.
According to the present invention, a locking device is provided and comprises an outer ring having an interior enclosed by a wall thereof, and a clutch disc received in the interior at a first side of the outer ring. A first pad is located on the clutch disc and includes a plurality of first protrusions. A second pad is located on the first pad and including a plurality of second protrusions. A plurality of balls are received in the interior and located between the adjacent first and second protrusions. A plurality of springs are biased between the far first and second protrusions. A locking disc is received in the interior at a second side of the outer ring. A tubular portion extends from a center of the locking disc and through the second pad, the first pad and the clutch disc. The tubular portion is securely connected to the second pad. The balls are located in a space between the clutch disc, the locking disc, an inner periphery of the outer ring, the first pad and the second pad. The locking disc includes a plurality of recesses into which the balls fall.
The locking disc of the present invention includes a screw hole to be connected with a screw bolt of a machine.
There are two O-rings located between the inner periphery of the outer ring and the locking disc and between the inner periphery of the outer ring and the clutch disc to properly position the two discs in the outer ring.
The present invention will be apparent to those skilled in the art by reading the following detailed description of a preferred embodiment thereof, with reference to the attached drawings, in which:
With reference to the drawings and in particular to
The clutch disc 4 is a circular disc and received in the interior. The clutch disc 4 is located at a first side of the outer ring 1 and includes a central hole. An underside of the clutch disc 4 is removably connected to a grinding wheel 8. A first O-ring 41 is located between the inner periphery of the outer ring 1 and the clutch disc 4 so as to provide a damping action to the outer ring 1 and the clutch disc 4 and further position the clutch disc 4 relative to the inner periphery of the outer ring 1.
The first pad 6 is received in the interior and located on the clutch disc 4, the first pad 6 includes a plurality of first protrusions 61 extending upward from a periphery thereof at equal interval. A central hole is defined through a center of the first pad 6.
The second pad 5 is received in the interior and located on the first pad 6, and the second pad 5 includes a plurality of second protrusions 51 extending downward from a periphery thereof at equal interval. A central hole is defined through a center of the second pad 5, and two first flat surfaces 52 are defined in an inner periphery of the central hole.
The balls 3 are received in the interior and located between the adjacent first and second protrusions 61, 51 respectively.
The springs 7 are received in the interior and located between the far first and second protrusions 61, 51. The two ends of each spring 7 are biased against the first and second protrusions 61, 52 respectively as shown in
The locking disc 2 is received in the interior and located at a second side of the outer ring 1. A tubular portion 20 extends from a center of the locking disc 2 and through the central hole of the second pad 5, the central hole of the first pad 6 and the central hole of the clutch disc 4. A clipping ring 23 as shown in
The arrangement of the parts mentioned above forms as a planet gear system wherein the outer ring 1 performs as the ring gears on the outside of the planet gear system, the balls 3 perform as the planet gears and the locking disc 2 performs as the sun gear.
As shown in
As shown in
Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.
