Patent Application
20090039131
1. Field of the Invention
The present invention relates to an adjustment device, and more particularly to an adjustment device composed of two worm rods coaxially combined together, two worm wheels respectively engaged with the two worm rods, and a shaft with a locking device to selectively control wires thereon.
2. Description of Related Art
A wire-guiding adjustment device is a structure for winding and releasing wires to drive position variation of a relative element by controlling the released length of the wires. For example, once an upper end and a lower end of a resilient backrest are controlled by the wires, the resilient backrest is bent to a big curved arc when the wires are released shorter. On the contrary, when the wires are released longer, the resilient backrest rebounds to keep straight. Therefore, the wire-guiding adjustment device has a wide application and various modifications in structures.
A conventional wire-guiding adjustment device is limited in technical aspect and generally comprises a single guiding wheel that can be selectively arranged to receive one or two counter wires to synchronously operate the wires for changing the shape or position of attached element such as the resilient backrest. However, controlling the resilient backrest usually needs multiple sets of the wire-guiding adjustment devices. For example, two conventional wire-guiding adjustment devices are needed for arc control and height control of the resilient backrest in operation so that setting the resilient backrest with the wire-guiding adjustment devices is not only cost-wasting but also time-consuming because it is hard to find proper locations and spaces for multiple sets to keep neat in appearance and also confusing in functions to users.
A main objective of the present invention is to provide an adjustment device with a dual-guiding structure that is composed of two worm rods, a shaft penetrating the two worm rods, and two worm wheels respectively engaged with the worm rods so that the adjustment device enables to receive multiple wires on the at least two worm wheels for multi-functional controlling.
main objective of the present invention is to provide an adjustment device with a dual-guiding structure that is convenient in assembly for workers and in operation for users.
To achieve the foregoing objectives, the adjustment device with a dual-guiding structure comprises:
two wire-guiding sets, each wire-guiding set having a worm wheel;
two worm rods coaxially combined together and respectively meshing with the worm wheels on the two wire-guiding sets, wherein each worm rod has an adjacent end and a locking recess defined in the adjacent end; and
a driving shaft axially penetrating the two worm rods and having a locking head mounted on the driving shaft to selectively engage with the locking recess on the worm rod.
Thereby, the two wire-guiding sets can be selectively and conveniently controlled by the driving shaft to control the rewind and release of the wire.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
An adjustment device with a dual-guiding structure in accordance with the present invention has two worm wheels respectively meshed with two coaxial worm rods (the worm wheel and worm shaft structure is an application of gear and threaded rod). Two worm rods are pivotally and axially fixed by a driving shaft. An adjacent end of each worm rod has a locking recess to receive a locking head mounted on the driving shaft. Thereby, the locking head is selectively engaged with one corresponding locking recess to drive the corresponding worm rod when the locking head on the driving shaft moves in reciprocation. Then, one worm wheel engaged with the corresponding worm rod is rotated to make the wires on the work wheel to rewind or release.
For more modification, the adjustment device selectively comprises at least two rods and at least two worm wheels respectively engaged with the worm rods so that the adjustment device enables to receive multiple wires on the at least two worm wheels for multi-functional controlling.
A preferred embodiment of the adjustment device with a dual-guiding structure has two wire-guiding set 1 each with a worm wheel 11 (as shown in
According to above described structure, a wire ring 12 on the wire-guiding set 1 is for attaching the wire 13. The wire-guiding set 1 enables to set one or more than two wire ring 12 to combine more wires for different operational purposes (because attaching one or two wires on the wire-guiding set is conventional, redundant description is eliminated). The rotation of the wire-guiding set 1 controls the rewind or the release of the wire 13. Because the worm wheel 11 on the wire-guiding set 1 meshes with the worm rod 2, the wire-guiding set 1 is positioned by the worm rod 2 when the driving shaft does not rotate (the worm rod 2 drives the worm wheel 11 but the worm wheel 11 can not drive the worm rod 2 in reverse). Therefore, the worm rod 2 efficiently controls the wire 13 on the wire-guiding set 1. When the locking head 31 on the driving shaft 3 slides into one corresponding locking recess 21 on the corresponding worm shaft 2 (as shown in
To make the locking head 31 smoothly and easily to engage with the locking recess, the locking head 31 has two distal ends and a leading angle 311 at each distal end (as shown in
Moreover, the wire rings 12 on the two wire-guiding sets 1 are arranged in different heights (as shown in
Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present invention of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts any be resorted to without departing from the spirit and scope of the invention.
