Patent Application
20080136198
1. Field of the Invention
This invention relates to an adjustable bracing device for holding an openable case, more particularly to an adjustable bracing device used for holding an openable case in a partially opened position.
2. Description of the Related Art
Referring to
The bracing device 1 includes first and second mounts 15,16 disposed to be secured to the left upright wall 23 and the major wall 30, respectively, a carrier frame 11 having an anchoring end 13 which is pivotally connected to the first mount 15, a linking end 16, and a guiding portion 18 for receiving a biasing member 12 therein, and a linking lever 14 having a power end 142 which is pivotally connected to the second mount 16, and a weight end 141 with a cam surface that is disposed to abut against an end of the biasing member 12 so as to place the biasing member 12 in a lightly or heavily compressed position to thereby deliver a smaller or larger biasing force such that the smaller or larger biasing force can counteract a smaller or larger torque for holding the lid member 3 in a fully or partially opened position. Thus, the lid member 3 can be opened to the fully opened position by the user, and can then be held in the partially opened position by the bracing device 1 to permit access to the accommodation chamber 20. However, since the biasing force of the biasing member 12 is fixed, it may not be sufficient to hold a relatively heavy lid member in the partially opened position, which may result in falling of the lid member. Moreover, the lid member may also fall as a result of metal fatigue of the biasing member 12 after a prolonged period of use.
The object of the present invention is to provide an adjustable bracing device with an adjusting member which permit adjustment of the biasing force of a biasing member thereof.
According to this invention, the adjustable bracing device includes first and second mounts adapted to respectively extend away from a case body and a lid member hinged to the case body, a carrier frame, a biasing member, a linking lever, and an adjusting member. The first mount has a first pivot end pivotally mounted to an anchoring end of the carrier frame. The second mount has a second pivot end which is pivotally mounted to a power end of the linking lever, and which, as a result of displacement of the center of gravity of the lid member, delivers larger and smaller torques in a partially opened position and a fully opened position, respectively. The carrier frame includes a linking end pivotally mounted to a fulcrum of the linking lever, and a guiding segment interposed between the anchoring end and the linking end to define a lengthwise path. The biasing member is disposed on the guiding segment, and has abutment and depressed ends that are proximate to the anchoring end and the linking end, respectively. The biasing member is compressible along the lengthwise path between a heavily compressed position, where the depressed end is closer to the abutment end to thereby deliver a larger biasing force, and a lightly compressed position, where the depressed end is remote from the abutment end to thereby deliver a smaller biasing force. The linking lever has a weight end having a cam surface which includes first and second regions that are angularly displaced from each other, and that are distant from the fulcrum respectively by a first length and a second length which is shorter than the first length. When the second region is brought to abut against the depressed end so as to place the biasing member in the lightly compressed position, the smaller biasing force counteracts the smaller torque, thereby permitting the lid member to be held in the fully opened position by virtue of a balance of forces. Once a tipping force is applied to disrupt the balance of forces so as to cause the second pivot end to deliver the larger torque, the weight end is caused to turn about the fulcrum axis against the larger biasing force to bring the first region to abut against the depressed end to thereby place the biasing member in the heavily compressed position, where the larger biasing force counteracts the larger torque, thereby permitting the lid member to be held in the partially opened position. The adjusting member is disposed to adjust the position of the abutment end relative to the anchoring end so as to vary the biasing force of the biasing member.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which:
Referring to
The first mount 53 is adapted to be secured on the upright wall 23 of the case body 2, and extends away from the upright wall 23 to terminate at a first pivot end 531. The second mount 54 is adapted to be secured on a major wall 30 of the lid member 3, and extends away from the major wall 30 to terminate at a second pivot end 541 which, as a result of displacement of the center of gravity of the lid member 3 when the lid member 3 is moved between the partially opened position and a fully opened position, delivers larger and smaller torques, respectively.
The carrier frame 4 includes an anchoring end 42 pivotally mounted on the first pivot end 531 of the first mount 53 about a first pivot axis parallel to the hinging axis, a linking end 43 opposite to the anchoring end 42, and a guiding segment 41 interposed between the anchoring end 42 and the linking end 43 to define a lengthwise path. The linking end 43 is configured to have two lug portions 431 which are spaced apart from each other in the transverse direction to define an accommodation space 432. The guiding segment 41 is configured to have two guiding walls 411 which are spaced apart from each other in the transverse direction to define an accommodation chamber 412 that extends along the lengthwise path. Two shoulder walls 44 extend in the transverse direction to respectively interconnect the lug portions 43 and the guiding walls 411.
The biasing member 7 is received in the accommodation chamber 412, extends along the lengthwise path, and has abutment and depressed ends 71, 72 which are opposite to each other, and which are proximate to the anchoring end 42 and the linking end 43, respectively. The biasing member 7 is configured to be compressible along the lengthwise path between a heavily compressed position, as shown in
The linking lever 5 includes a power end 52 which is pivotally mounted on the second pivot end 541 of the second mount 54 about a second pivot axis parallel to the first pivot axis, and a fulcrum 58 which is pivotally mounted on the linking end 43 about a fulcrum axis parallel to the first pivot axis by means of a linkage pin 59 that extends through the lug portions 43 and that is received loosely in a key slot 581 formed in the fulcrum 58 so as to permit the fulcrum 58 to vary in location for facilitating a smooth angular displacement of the linking lever 5. The linking lever 5 further includes a weight end 56 which is received in the accommodation space 432, and which has a cam surface 561. The cam surface 561 includes first and second regions (561a, 561b) which are angularly displaced from each other about the fulcrum axis, and which are distant from the fulcrum axis by a first length and a second length, respectively. The second length is shorter than the first length. A pressure transmitting member 8 has a major wall 81 which is interposed between the depressed end 72 of the biasing member 7 and the shoulder walls 44. Thus, as shown in
The adjusting member 6 includes an abutment wall 63, an end cap 61, and an adjustment screw 62. The abutment wall 63 is disposed proximate to the anchoring end 42 of the carrier frame 4 to confront and cooperate with both the shoulder walls 44 to define the lengthwise path, and has a screw hole 631 formed therethrough. The end cap 61 is detachably engaged with the abutment end 71 of the biasing member 7, and has a pushed surface which is disposed to abut against the abutment wall 63. The adjustment screw 62 has a head portion 621 and a threaded shank portion 622 opposite to the head portion 621. The threaded shank portion 622 is threadedly engaged in the screw hole 631 so as to be movable between an adjusted position, where the abutment end 71 of the biasing member 7 is closer to the depressed end 72 as a result of a screw-in movement of the threaded shank portion 622 to push the pushed surface of the end cap 61 by virtue of turning of the head portion 621 using a tool (not shown), and an unadjusted position, where the abutment end 71 is remote from the depressed end 72. When the lid member 3 is relatively heavy, or when the biasing member 7 suffers from metal fatigue, the user can turn the head portion 621 to move the threaded shank portion 622 from the unadjusted position to the adjusted position so that the position of the abutment end 71 relative to the anchoring end 42 is adjusted to thereby increase the biasing force of the biasing member 7. Thus, the lid member 3 can be held firmly in the partially opened position. On the contrary, if the user needs to apply a relatively large force to the lid member 3 in order to counteract the biasing force of the biasing member 7 when closing the lid member 3, the user can screw-out the adjustment screw 62 so as to move the abutment end 71 away from the depressed end 72, thereby decreasing the biasing force of the biasing member 7. While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.
