1. Field of the Invention
The present invention relates to a pivotal device with open lightly and close heavily, and more particularly to a pivotal device that is mounted between a cap and a base of a device and therefore, the cap can open or close relative to the base.
2. Description of the Related Art
A conventional pivotal device is mounted between a cap and a base of a device so that the cap can open or close relative to the base. When the cap is closed relative to the base, the user slows down the speed of the cap closure to prevent the cap from bumping the base. Also, when the cap is opened relative to the base, the user opens the cap with a quick speed to open the cap as quickly as possible. However, with the same friction between the components of the conventional pivotal device, the user should open or close the cap using extra force.
Therefore, the invention provides a pivotal device with open lightly and close heavily to mitigate or obviate the aforementioned problems.
The main objective of the present invention is to provide a pivotal device with self friction to provide open lightly and close heavily to open or close the cap relative to the base without the extra force by the user.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
The axle (10) has a fixing portion (11) formed in a first end of the axle (10) and a non-circular bar (12) formed in a second end of the axle (10). The bar (12) has a threaded portion (121) formed a free end of the bar (12). Ahead (13) is formed radially between the fixing portion (11) and the bar (12).
The bracket (20) is mounted around the bar (12) and has two fastening holes (21) defined through the bracket (20).
With further reference to
The actuating washer (40) is mounted securely on the bar (12) of the axle (10) and has a non-circular orifice (41) defined through a center of the actuating washer (40). The non-circular orifice (41) engages the non-circular bar (12) to mount the actuating washer (40) securely on the axle (10). The actuating washer (40) is adjacent to the second side of the resisting washer (30) and has two lugs (42) extending towards the resisting washer (30) and opposite to each other. When the actuating washer (40) is rotated relative to the resisting washer (30), one of the lugs (42) slides along the skewed surface (32).
The elastic unit (50) and the friction washer (60) are respectively mounted around the bar (12). The fastener (70) is mounted around and fixed to an end of the bar (12). The fastener (70) can be a nut to screw to the threaded portion (121) of the bar (12).
The present invention is mounted between a base and a cap of an electronic appliance. The fixing portion (11) is fixed to the cap and the bracket (20) is fixed to the base. When the cap is opened or closed relative to the base, the axle (10) is rotated relative to the bracket (20) and the axle (10) drives the actuating washer (40) to rotate relative to the resisting washer (30). Hence, the lugs (42) slide along the skewed surface (32).
When the cap is closed, the lugs (42) sliding from the second end to the first end of the skewed surface (32) so that the friction between the actuating washer (40) and the resisting washer (30) is enhanced. Therefore, the enhancing friction slows down the closing speed of the cap.
When the cap is opened, the lugs (42) sliding from the first end to the second end of the skewed surface (32) so that the friction between the actuating washer (40) and the resisting washer (30) is decreased. Therefore, the decreasing friction speeds up the opening speed of the cap.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.