Patent Application
20140001674
1. Field of the Invention
The present invention relates to a manufacturing method for a hinge, especially to a manufacturing method for a hinge that is mounted between the cover and the base of a flip device.
2. Description of the Prior Arts
Hinge is a device to rotate two objects relatively, and is usually used in flip devices, such as notebook computers. Two ends of the hinge are respectively connected securely to the base and the cover of the notebook computer. Then the cover can be opened or closed relative to the base.
A conventional hinge has a central element, a surrounding element and a fastener. The surrounding element is mounted rotatably around the central element. The fastener is mounted on an end of the central element. The surrounding element is clamped between the fastener and the central element, which keeps the surrounding element from departing axially from the central element. When the hinge is used, the central element and the surrounding element are respectively connected securely to two objects, which are to rotate relatively.
The conventional hinge only can allow two objects to rotate relative to each other. For achieving more functions, the conventional hinge usually comprises other elements such as a convex and concave washer assembly. The convex and concave washer assembly has two actuating washers and a spring. The actuating washers have corresponding shapes. The actuating washers and the spring are mounted around the central element. One of the actuating washers is connected securely to the central element, and the other one of the actuating washers is connected securely to the surrounding element. The spring makes the actuating washers abut each other. Normally, the actuating washers engage each other, but once the surrounding element and the central element are rotated relatively by an external force, the actuating washers rotate relatively as well. Then the actuating washers disengage from each other, and compress the spring therefore. When the external force is removed, the spring then pushes one of the actuating washers to make the actuating washers recovered to engage each other. As a result, when the actuating washers engage each other, the two objects are held at a specific angle, such as 90 degrees.
The conventional manufacturing method for the hinge comprises:
Making the components. The central element, the surrounding element and the fastener are made, and the process may comprise cold drawing, forging, turning, heat treatment, surface treating and so on.
Assembling the components. The surrounding element is mounted around the central element. Then the fastener is mounted on an end of the central element, and the fastener and the central element clamp the surrounding element. The fastener may be a nut and is screwed onto the end of the central element. However, because the nut is usually screwed tightly to prevent the nut from being loosened, the hinge has to further comprise an abrasion washer to reduce the abrasion, or the nut has to be glued to the central element.
To sum up, making each component takes much time and effort, and the subsequent assembling work is also complicated. Besides, the above-mentioned conventional manufacturing method is merely described in brief for illustrative purpose. In practice, the hinge may further comprise other components, such as a convex and concave washer assembly. Then the assembling takes more time and efforts, and the cost is increased therefore. Moreover, the conventional hinge comprises many components such that the connection between the components of the conventional hinge is not stable enough. Finally, the conventional hinges are mostly made of metal, which also costs a lot.
To overcome the shortcomings, the present invention provides a manufacturing method for a hinge to mitigate or obviate the aforementioned problems.
The main objective of the present invention is to provide a manufacturing method for a hinge that comprises fewer components, is of a simplified structure and made by a simplified process, and lowers the cost.
The manufacturing method for a hinge in accordance with the present invention has steps of forming one of a central element and a surrounding by injection molding, cooling down the formed element, and forming the other element on the priorly-formed element by injection molding such that a limit segment of the surrounding element is mounted around and flush with the neck segment having a smallest width of the central element, which keeps the surrounding element from departing axially from the central element, and further reduces the number of the components and simplifies a structure of the hinge. Because a melting point of the element formed priorly is higher than a melting point of the element formed later, the element formed later does not attach to the priorly-formed element after being cooled down. Therefore, the two elements are relatively rotatable. Additionally, the central element and the surrounding element are respectively formed integratedly so the stability of the hinge is higher compared to a conventional hinge comprising so many components. Finally, because a manufacturing process of the hinge is accomplished after injection molding twice, the process of manufacturing the hinge is more convenient and faster, and the cost is lowered compared to the process of manufacturing a conventional hinge that involves much assembling work.
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
With reference to
After being formed by injection molding, the central element 10 is cooled down and solidified.
With reference to
In another embodiment, the surrounding element 20 is made of Polyphthalamide (PPA) and glass fiber, wherein a weight ratio of Polyphthalamide to glass fiber is 2 to 1. This material is a plastic material from EMS GRIVORY®, and the model number of the material is GV-5H.
With reference to
The flip device may be portable electronic devices or other devices, such as notebook computers, or cosmetics boxes.
With reference to
In the manufacturing method with the present invention, the central element 10 having a higher melting point is formed by injection molding, and then is cooled down. Afterwards, the surrounding element 20 is formed on the central element 10 by injection molding. Because the melting point of the surrounding element 20 is lower, the central element 10 is not melted when the surrounding element 20 wraps the central element 10 and is being formed by injection molding such that the surrounding element 20 is not attached to the central element 10 after being cooled down. Additionally, the mounting segment 11 and the neck segment 12 are circular in cross section, and an inside surface of the surrounding element 20 is mounted around and is flush with the mounting segment 11 and the neck segment 12. As a result, the inside surface of the surrounding element 20 is circular as well. Then the surrounding element 20 is rotatable relative to the central element 10. Besides, when the surrounding element 20 wraps the central element 10 and is being formed by injection molding, the material of the surrounding element 20 flows into and is mounted around the neck segment 12 of the central element 10 such that after the surrounding element 20 is cooled down and solidified, the limit segment 22, which wraps the neck segment 12, abuts axially the mounting segment 11 and the fastening segment 13, which are respectively on the two sides of the neck segment 12. As a result, the central element 10 is unable to move axially relative to the surrounding element 20. To sum up, after being formed by injection molding twice, the hinge 30 reaches the essential requirement of being rotatable relatively but being unable to move relatively.
Moreover, the central element 10 forms the positioning protrusions 111 and compressing holes 112 after being formed by injection molding, and the surrounding element 20 forms the positioning recesses 211 after being formed by injection molding again such that the hinge 30 further reaches the requirement of being held at multiple angles.
The manufacturing process of the hinge 30 is accomplished after injection molding twice, and the hinge 30 meets the requirements mentioned above at the same time. As a result, the hinge is convenient in manufacturing and is beneficial for mass production. The cost is lowered therefore.
Furthermore, the hinge 30 is made of plastic, which further lowers the cost. Finally, the hinge 30 is formed by injection molding, so the central element 10 and the surrounding element 20 are respectively formed integratedly to enhance the stability when in use.
In another preferred embodiment as shown in
With reference to
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 features of the invention, the disclosure is illustrative only. Changes may be made in the 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.
