1. Technical Field The present invention relates to tables, and more particularly to a table with its table board adjustable in both height and pitch.
2. Description of Related Art
Adjustable tables have been extensively applied as, for example, drawing tables, map display stands, notice boards and so on. Such a table has its table board adjustable in pitch and thus can satisfy users' practical needs.
One example of the known adjustable tables is as described in U.S. Pat. No. 4,058,066. The prior-art table has a pair of front legs, a pair of upper legs and a table board. The front legs are configured to swing with respect to the upper legs, and the upper legs can swing with respect to the table board. Since the angle-adjusting mechanism between the front legs and the upper legs is deposited behind the table board, for table adjustment, a user has to first move to the lateral of the table to operate the angle-adjusting mechanism and then move back to the front of the table to check whether the adjusted pitch is satisfying. Such operation may have to be repeated for several times before the desired pitch is achieved.
Therefore, it would be desirable to have a table allows convenient adjustment of its table board in both pitch and height.
One objective of the present invention is to provide a table whose table board can be conveniently adjusted by a user standing in front of the table.
To achieve this and other objectives of the present invention, the disclosed adjustable table comprises a base, a pair of upper rods, a table board and a first pitch-adjusting mechanism. The base includes a pair of legs, each having a leg top, a slot and a plurality of dents, wherein the dents are separated and arranged abreast along a length of the slot. Each of the upper rods has a first connecting end and a second connecting end. The first connecting end is pivotally connected to the corresponding leg top. The leg and the corresponding upper rod include a first included angle. The table board is connected to the second connecting ends. The first pitch-adjusting mechanism serving to adjust the first included angle includes two positioning rods, a lever and a plurality of links. Each of the positioning rods has a pivotal end and a slotted end. The pivotal end is pivotally connected to the corresponding upper rod. Each of the slotted ends has an insert extending transversely. The two inserts have an engaged state and a disengaged state. In the engaged state, the two inserts are retained in the dents so that the first included angle is fixed. In the disengaged state, the two inserts leave from the dents and are free to slide along the slots, thereby changing the first included angle. The lever swings against a shaft, which is supported by at least one of the upper rods and close to the second connecting end of the upper rod. The links build kinetic connection between the positioning rods and the lever, so that when the lever is operated, the two inserts are switched between the engaged and disengaged states.
With the configuration as described above, the present invention allows a user standing in front of the table board to easily make adjustment by operating the lever to disengage the inserts, changing the first included angle and then releasing the lever to make the table board posed as desired.
The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
While a preferred embodiment provided hereinafter for illustrating the concept of the present invention as described above, it is to be understood that the components of the embodiment shown in the accompanying drawings are depicted for the sake of easy explanation and need not to be made to exact scale. Unless otherwise noted, like elements will be identified by identical numbers throughout all figures.
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The base 10 comprises a pair of legs 11 and a pair of feet that support the legs 11 to stand upright. In another embodiment, the legs 11 may be adjustable in length. Each of the legs 11 has a leg top 14 and a slot 15 deposited near the leg top 14. The slot 15 is provided with a plurality of dents 16 arranged along the length of the slot 15 and communicated with the slot 15.
Each of the upper rods 20 has a first connecting end 21 and a second connecting end 22. The first connecting end 21 is pivotally coupled with the corresponding leg top 14. A first included angle is included by each said leg 11 and the corresponding upper rod 20. Additionally, at least one said upper rod 20 has a lengthwise unit 23 extending along its length. In the illustrated embodiment, each of the upper rods 20 is equipped with the lengthwise unit 23. The lengthwise unit 23 may comprise a shank portion 24 and two fixing segments 25. The two fixing segments 25 are located at two ends of the shank portion 24 for attaching the shank portion 24 to the upper rod 20, such that the shank portion 24 is parallel to and separated from the upper rod 20 itself.
The table board 30 is connected to the second connecting ends 22. Preferably, the table board 30 and each said upper rod 20 include an adjustable second included angle. The table board 30 has two lower arms 31. The lower arm 31 is assembled to the lower surface of the table board 30 and aligned with the corresponding upper rod 20. The lower arm 31 has one end pivotally connected with the second connecting end 22 of the corresponding upper rod 20 and an opposite end left free.
The first pitch-adjusting mechanism 40 serves to adjust the first included angle and comprises two positioning rods 41, a lever 42 and several links. Each of the positioning rods 41 has a pivotal end 411 and a slotted end 412. The pivotal end 411 is pivotally connected to the corresponding upper rod 20, and the slotted end 412 has an insert 413 transversely extending. The two inserts 413 are in either an engaged state or a disengaged state simultaneously. In the engaged state, as shown in
Furthermore, the links are connected between and thereby link the positioning rod 41 and the lever 42. The links may include a first transverse link 44, a second transverse link 45, a first vertical link 46 and a second vertical link 47. The first transverse link 44 is connected between the pivotal ends 411 of the two positioning rods 41. The second transverse link 45 is connected between the slotted ends 412 of the two positioning rods 41. The first vertical link 46 is connected between the first and second transverse links 44, 45. The second vertical link 47 is connected between the first vertical link 46 and the lever 42.
Preferably, the disclosed table may further comprise a returning means that returns the two inserts 413 to the engaged state. The returning means comprises at least one elastic member connected between components that have variable angles or lengths. In the present embodiment, two springs 48 are provided between the two upper rods 20 and the first transverse link 44, respectively, for facilitating the foregoing return.
The second pitch-adjusting mechanism 50 serves to adjust the second included angle and has two support arms 51. Each of the support arms 51 can rotate with respect to the table board 30 against a first pivot 52, and can rotate with respect to the corresponding upper rod 20 against a second pivot 53. A distance between the first pivot 52 and the second connecting end 22 defines a first length. A distance between the second pivot 53 and the second connecting end 22 defines a second length. A distance between the first and second pivots 52, 53 defines a third length. Therein, one of the first, second and third lengths is adjustable. Thus, according to the Law of Cosines, change of the adjustable length leads to change of the second included angle.
For instance, in the present embodiment, the second length is adjustable. The first pivot 52 is located between two ends of the lower arm 31. The support arm 51 is directly or indirectly connected to the lengthwise unit 23 of the corresponding upper rod 20. In other embodiments, the adjustable length is the first or third length. U.S. Pat. No. 4,058,066 is an example wherein the third length is adjustable.
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With the configuration as described above, the present invention uses at least one adjustable joint to make the table board adjustable in pitch and height, and allows a user standing in front of the table board to easily make adjustment by operating the lever to disengage the inserts and then changing the first included angle. Thereby, the adjustment of the table board in pitch and height can be accomplished easily and rapidly, thereby satisfying the user's practical needs.
The present invention has been described with reference to the preferred embodiments and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims.