Patent Application
20080078776
Many aspects of the present torsion spring configuration and the present releasable casing with the torsion spring configuration can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Reference will now be made to the drawings to describe in detail, the preferred embodiments of the present torsion spring configuration and the present releasable casing with the torsion spring configuration.
Torsion springs are helical springs used to apply torque or store rotational energy. Torque by definition is a force that produces rotation. A torsion spring exerts a force of torque in a circular arc, and arms of the torsion spring rotate about a central axis thereof.
A typical torsion spring includes a cylindrical body constructed with a helical wire, two ends of the helical wire form a pair of arms extending from the body. In use, the body is typically sleeved on a rod, either one of the pair of arms is fixed, while the other arm (a free arm) is movable relative to the rod.
When a force is acted on the free arm at a distance from an axis of the torsion spring, the torque (a.k.a. moment), which is equal to the force multiplied by the arm of force (i.e. a distance of a point of contact of the arm), causes the free arm to rotate around the axis, thus, kinetic energy is transformed to potential energy.
When the torsion spring releases/exerts the potential energy stored, the free arm of the torsion spring rotates and returns to an initial position. A force acted from the free arm of the torsion spring gradually decreases as the free arm moves closer to the initial position. Supposing that the above torsion spring is utilized to release a lid of a releasable casing, a force applied to the lid by the torsion spring would gradually decreases. This results in that the lid rotates unevenly together with the free arm of the torsion spring during the releasing process.
As described above, it is difficult to choose an appropriate torsion spring for a given releasable casing. This is because in the given releasable casing, if the torsion spring thereof carries a relatively great torque, the lid would open and strike the releasable casing fiercely, resulting in undesired ricochets, shakes, or vibrations. Thus, the lid, or the releasable casing would be prone to damage. On the other hand, if the torsion spring carries a relatively small torque, the lid cannot open at a greatest releasing angle.
Hereinafter, a torsion spring configuration is described in detail to solve the above problem satisfactorily.
Referring to
The lid 10 includes a first supporting portion 12 and a second supporting portion 14, both of which are in quadrant shapes. The first and second supporting portions 12 and 14 are formed near an edge of the lid 10 with axes thereof superposing each other and the rotating axis OO of the lid 10. A positioning slot 16 perpendicular to the rotating axis OO of the lid 10 is defined beside the second supporting portion 14. The first supporting portion 12 and the positioning slot 16 are respectively used to position the first torsion spring 30 and the second torsion spring 40. The second supporting portion 14 forms a partial gear 142 to engage/mesh with a gear (not shown) positioned in the base 20 thus, slowing down the lid 10 during an opening procedure and dampening an impact between the lid 10 and the base 20 when reaching the largest opening angle.
The base 20 defines a first opening 22, a second opening 24, and a third opening 26. The first opening 22 is defined near an edge of the base 20 corresponding to the first supporting portion 12 of the lid 10 allowing the first supporting portion 12 to extend therethrough. Similarly, the second opening 24 is defined near the edge of the base 20 corresponding to the second supporting portion 14 of the lid 10 allowing the second supporting portion 14 to extend therethrough. The third opening 26 is defined near the second opening 24 to allow an arm of the second torsion spring 40 to extend therethrough reaching the positioning slot 16 of the lid 10.
The first torsion spring 30 includes a first body 32 spun in a coil, and a first arm 34 and a second arm 36 extending from the first body 32. The first arm 34 extends from an end of the first body 32 forming an S-shape, and the second arm 36 extends tangently from an opposite end of the first body 32. The second arm 36 is relatively a straight arm extending from the first body 32, and the first arm 34 includes a first portion 342 extending relatively straight along an opposite direction to the second arm 36, an arc-shaped second portion 344, and an arc-shaped third portion 346. The second portion 344 and the third portion 346 are end-to-end, and the bending directions thereof are opposite to each other. That is, a center point of an imaginary circle conformed to the second portion 344 and a center point of an imaginary circle conformed to the third portion 346 are respectively positioned at two opposite sides of the first arm 34.
The second torsion spring 40 includes a second body 42 converted in coils, and a third arm 44 and a fourth arm 46 extending from the second body 42. The third arm 44 and the fourth arm 46 are straight arms. The third arm 44 extends tangently from an end of the second body 42, and the fourth arm 46 extends radially from another opposite end of the second body 42.
The first body 32 and the second body 42 are sleeved on rods (not shown) formed in the base 20 correspondingly. The first arm 34 of the first torsion spring 30 and the third arm 44 of the second torsion spring 40 are fixed to the lid 10 of the releasable casing 100, while the second arm 36 of the first torsion spring 30 and the fourth arm 46 of the second torsion spring 40 are fixed to the base 20. Detailedly, the first arm 34 resists against the first supporting portion 12 of the lid 10, and the third arm 44 is restricted in the positioning slot 16 defined on the lid 10.
Referring to
Different states during an opening procedure of the lid 10 are respectively shown in
Firstly referring to
Subsequently referring to
Finally referring to
As described above, from the closed state to the half opened state, the first torsion spring 30 applies a first force onto the first supporting portion 12 holding the first supporting portion 12 in the opening procedure. Meanwhile, the second torsion spring 40 applies a second force onto the lid 10 releasing the lid 10. During such a procedure, the first torsion spring 30 holds the lid 10, and the second torsion spring 40 releases the lid, thus, a resultant force of the first force and a second force applied to the lid 10 releasing the lid 10 is adjusted. As the opening angle increases, the first force applied by the first torsion spring 30 decreases, and the second force applied by the second torsion spring 40 decreases. Therefore, the resultant force of the first force and the second force changes slightly or remains constant. From the half opened state to the opened state, the third portion 346 of the first arm 34 moves into the sliding channel 120. The first force applied by the first torsion spring 30 disappears, and a third force is generated by the first arm 34 supporting the lid 10, helping the lid 10 to reach and remain at the largest opening angle. The second force applied by the second torsion spring 40 decreases continuously. When the third portion 346 moves into the sliding channel 120, the second force and the third force applied respectively by the first torsion spring 30 and the second torsion spring 40 together support the lid 10, and keep the lid 10 at the largest opening angle.
A closing procedure is a reverse procedure of the above opening procedure.
It is clear that the first torsion spring 30 cooperates with the second torsion spring 40 to maintain the releasing force of lid 10 during the releasing procedure, and to support the lid 10 at the largest opening angle so as to eliminate/depress shakes of the lid 10 in the opened state. Such a configuration of the first torsion spring 30 and the second torsion spring 40 effectively resolves common problems of conventional torsion springs. The releasable casing 100 is superior to those by having a substantially constant releasing force on the lid 10 and a long work life thereof due to depressed/eliminated strikes. This torsion spring configuration can be utilized in many electronic devices, such as a game player, a disc player, a tool box, or even a dressing case, etc.
It should be emphasized that the above-described embodiments of the present invention, including any preferred embodiments, are merely possible examples of implementation of the principles of the invention, and are merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and be protected by the following claims.
