LONG LEG FIXATION DEVICE

Description

[Technical Field]

[0001] The present invention relates to a foldable table, and more particularly, to fixing legs hinged to a table top plate.[Background Art]

[0002] A table may have a structure that allows it to be folded, assuming that it is stored when not in use. The table, which has the structure in which th e top plate is folded vertically, has various functions according to the s torage form, such as tilting one top plate or tilting the top plates so as to separate and face each other. 0n the other hand, the table having the structure in which the legs are folded also has various functions such as folding the legs one by one or folding the plurality of legs in conjunctio n with each other.

[0003] For the tables with the foldable structure, it is important to fix the top plate or legs during use. If the top plate or legs are unintentionally fo lded during use, not only will the articles placed on the top plate be sca ttered, but there is a risk of causing an injury to the user.

[0004] As a mechanism for fixing the foldable top plate, a table in which a clawshaped member is locked to a step portion and the top plate is restrained in a horizontal posture is disclosed (cf patent document 1).[Description of the Prior Art][Patent Documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2004-187851 [Patent Document 2] Japanese Unexamined Patent Application Publication No. H4-54905

[0006] A further long leg fixing device is known from JP 2008 229326 A.[Disclosure of the Invention][Problems to be Solved by the Invention]

[0007] In the table having the structure for locking the engaging portion and the metal fitting at the tip of the swing member described above, there is an advantage of few unsteadiness at the time of opening the leg by matching of the shapes of the metal fitting and the linking crosspiece. However, th ere is a limit to the elastic force of the spring, and especially when the elastic force is insufficient for long legs and an unexpected external fo rce not from the release operation acts on the swing member, the engagemen t is suddenly released and the legs may be folded. Further, if the elastic force of the spring is excessive, there is a concern that the linking cro sspiece may be deformed, creating a problem that the linking crosspiece an d the leg must be strengthened.

[0008] Therefore, the objective of the present invention is to provide a long leg fixing device which, while maintaining the conventional effect of suppres sing unsteadiness when legs are open by supporting a bottom surface and a side surface of a linking crosspiece, maintains the open-leg state by mean s of engagement with a component on the side surface of the linking crossp iece, without relying on the elastic force of a spring, and at the same ti me facilitating an operation to release a closed-leg state.[Means for solving the problem]

[0009] That is, the present invention is intended to achieve the above-mentioned object.

[0010] According to the invention, there is provided a long leg fixing device for a table, the table having four long legs and having a structure in which two of the long legs are linked by means of a crossbeam portion, and in wh ich said two long legs are fitted to the table in such a way as to be capa ble of pivoting by means of a hinge to move together to open and close the long legs, the long leg fixing device comprising: a base that is fixable to a top plate of the table; an arm pin inserted into said base; an arm an d a lever arranged to swing around the arm pin, said lever having a claw p ortion; a cam pin inserted through said arm and said lever and which is no t inserted into the base, said cam pin being a common shaft for said arm a nd said lever; a lever cam arranged to swing around said cam pin as a shaf t and arranged to engage with the claw portion of the lever, the lever cam including a hanging plate portion in the center thereof; a latch; a link plate including a base portion and a claw portion arranged to interlock wi th the latch; a seat portion which is mountable to the crossbeam portion o f the table, the arm and the latch being configured to grip the seat porti on; and, a latch receiver and a push plate arranged inside the latch, and a latch spring is arranged in a space surrounded by the latch receiver and the push plate, wherein the diameter of a pi n hole of the lever cam through which said cam pin is inserted is formed to be slightly larger than the diameter of the body portion of said cam pin, and a pin hole of said lever is formed i n the shape of a slot, wherein the lever is operable to cause the hanging plate portion to come into contact with the base portion of the link plate and to cause the claw portion of the link plate to interlock with the lat ch, such that the arm and the latch are interlocked and the link plate is moved in the direction of the lever, wherein the latch spring is a compression coil spring, which is locked to the base portion of the latch receiver and the spring receiver portion of the latch, and always urges the latch and the latch receiver and wherein the lever cam that engages with the claw portion of the lever swings around the cam pin in response to the swing of the lever.

[0011] The lever may be operable to cause the latch to slide and release the seat portion in a first step and the arm to swing to release the lock with the seat portion in a second step.

[0012] The long leg fixing device may further include: a base pin provided in the base; and a hook that is movable with an operative swing of the lever suc h as to engage the hook with the base pin, and wherein the arm is fixable to lock the crossbeam portion.

[0013] By the operation of the lever, the hook and the base pin may be releasable in a first step and the arm swingable to release the lock with the seat p ortion in a second step.[Effects of the Invention]

[0014] Since the long leg fixing device of the present invention grips the crossb eam portion by the arm and the latch, there is an advantage that the maint enance of the open leg state does not need to rely on a strong spring for engaging the crosspiece and the arm. In addition, by operating the lever, the mechanism enables two-step operation of releasing the fixed state of t he long leg as the first step and swinging the arm as the second step, so that the long leg can be operated only by operating the lever. The fixing can be released and the long legs can be easily opened and closed.[Brief Description of Drawings]

[0015] FIG. 1 is a perspective view showing the table provided with the long leg fixing device in the present invention, in which the long leg fixing devic e grips the crossbeam portion between the opened long legs. FIG. 2 is a bottom view showing the table provided with the long leg fixin g device in the present invention, in which the long leg fixing device gri ps the crossbeam portion of the opened long leg. FIG. 3 is a bottom view showing the table provided with the long leg fixin g device in the present invention, in which the long leg fixing device loc ks the crossbeam portion of the closed long legs. FIG. 4 is a cross-sectional view showing the table provided with the long leg fixing device in the present invention, in which the long leg fixing d evice grips a crossbeam portion of the opened long leg. FIG. 5 is a perspective view of the seat portion of the long leg fixing de vice in the present invention. FIG. 6 is a perspective view of the latch of the long leg fixing device in the present invention. FIG. 7 is a cross-sectional view showing the table provided with the long leg fixing device in the present invention, in which the long leg fixing d evice is released from gripping the crossbeam portion of the opened long l eg. FIG. 8 is a perspective view of the lever cam of the long leg fixing devic e in the present invention. FIG. 9 is a perspective view of the link plate of the long leg fixing devi ce in the present invention. FIG. 10 is a cross-sectional view showing the table provided with the long leg fixing device in the present invention, in which the long legs are in the middle of the closed or opened. FIG. 11 is a cross-sectional view showing the table provided with the long leg fixing device in the present invention, in which the long leg fixing device locks the crossbeam portion of the closed long legs. FIG. 12 is a perspective view of the hook of the long leg fixing device of the present invention. FIG. 13 is a cross-sectional view showing the table provided with the long leg fixing device in the present invention, in which the long leg fixing device is capable of the opening the legs from the state in which the cros sbeam portion of the closed long legs are locked. [Description of Embodiments]

[0016] In the present invention, the following embodiments will now be described with reference to the accompanying drawings.[Embodiment 1]

[0017] A long leg fixing device 1 in the present invention is used for a table th at is erected using four long legs having a structure in which two of the long legs are linked by means of a crossbeam portion, and said two long le gs are fitted to the table in such a way as to be capable of pivoting by m eans of a hinge, move together to open and close the legs. FIG. 1 is a per spective view showing the table 2 provided with the long leg fixing device 1 in the present invention, in which the long leg fixing device 1 grips a crossbeam portion 4 between opened long legs 3, and seen from the back su rface of a top plate 5. In this embodiment, the back surface side of the t op plate 5 may be referred to as the underside surface. The long legs 3 ar e fitted to the table 2 by hinges 6, and the two long legs 3 are linked by the crossbeam portion 4. The other two legs (not shown) may also been gri pped by providing the other long leg fixing device on the back surface of the table 2.

[0018] FIG. 2 is a bottom view showing the table 2 provided with the long leg fix ing device 1 in the present invention, in which the long leg fixing device 1 grips the crossbeam portion 4 of the opened long legs 3. At the center of the crossbeam portion 4, a seat portion 7 formed to an approximately U-shaped cross section is mounted so as to surround a part of three surfaces of the crossbeam portion 4. In the open-leg state, the tip end portion of an arm 8 of the long leg fixing device 1 is locked to the seat portion 7. The fixing means of the seat portion 7 is not limited thereto, but an alt ernative example thereof includes fixing means using screws.

[0019] FIG. 3 is a bottom view showing the table 2 provided with the long leg fix ing device 1 in the present invention, in which the long leg fixing device 1 locks the crossbeam portion 4 of the closed long leg 3. In the closed l eg state, a long plate portion of the arm 8 of the long leg fixing device 1 is fixed at a position parallel to the top plate 5.

[0020] FIG. 4 is a cross-sectional view showing the table 2 provided with the lon g leg fixing device 1 in the present invention, in which the long leg fixi ng device 1 grips the crossbeam portion 4 of the opened long legs 3, and t aken along the line A-A of FIG. 2. And, FIG. 5 is a perspective view of th e seat portion 7. The arm 8 is a component formed by bending a plate-shape d member, and has a space inside. Inside the arm 8, a latch 9 is slidably housed in a longitudinal direction of the arm 8. FIG. 6 is a perspective v iew of the latch 9. In the open-leg state, the claw portion 9a of the late h 9 is locked to an opening portion 7a and a raised portion 7b of the seat portion 7 by the urging of the latch spring 10.

[0021] The width of the claw portion 9a of the latch 9 is formed to be narrower t han the width of the opening portion 7a of the seat portion 7 and wider th an the width of the raised portion 7b. When the long leg fixing device 1 g rips the crossbeam portion 4 of the opened long legs 3, the claw portion 9 a gets into the opening portion 7a and comes into contact with the raised portion 7b. In this way, when the claw portion 9a is locked to the opening portion 7a and the raised portion 7b, the seat portion 7 is in a state of being gripped by the arm 8 and the latch. The open-leg state of the long leg 3 linked to the crossbeam portion 4 is maintained by the seat portion 7 mounted thereto.

[0022] FIG. 7 is a cross-sectional view showing a state in which the table 2 prov ided with the long leg fixing device 1 in the present invention is release d from gripping the crossbeam portion 4 of the opened long leg 3. The cutt ing line is the same as the line A-A in FIG 2. In the long leg fixing devi ce 1 in the present invention the internal mechanism of the arm 8 is opera ted by a lever 11. The arm 8 and the lever 11 swing around an arm pin 13 i nserted into a base 12 fixed to the top plate 5 of the table 2. Further, t he arm 8 and the lever 11 have a cam pin 14 which is not inserted into the base 12 as a common shaft. The cam pin 14 is a shaft that allows the leve r cam 15 to swing. The fixing means of the base 12 is not limited thereto, but an alternative example thereof includes fixing means using screws.

[0023] FIG. 8 is a perspective view of the lever cam 15. The diameter of a pin ho le 15b through which the cam pin 14 is inserted is formed to be slightly l arger than the diameter of the body portion of the cam pin 14, and the pin hole 11b of the lever 11 is formed in the shape of a slot. The diameter o f the pin hole (not shown) of the arm 8 is also formed to be slightly larg er than the diameter of the body portion of the cam pin 14, similarly to t he pin hole 15b. Further, FIG. 9 is a perspective view of a link plate 16. The claw portion 16b of the link plate 16 engages with a link plate recei ving portion 9c of the latch 9.

[0024] As shown in FIG. 7, when the lever 11 is operated and slightly pushed towa rd the top plate 5, the lever cam 15 that engages with the claw portion 11 a of the lever 11 swings around the cam pin 14 in response to the swing of the lever 11. At this time, the position of the cam pin 14 inserted into the arm 8 which has not yet swung will not change. Even if the position of the cam pin 14 does not change, since the pin hole 11b of the lever 11 ha s the shape of the slot, a slight swing of the lever 11 about the arm pin 13 is allowed. The lever cam 15 is provided with a hanging plate portion 1 5a in the center thereof, comes into contact with a base portion 16a of th e link plate 16. The link plate 16 is moved in the direction of the lever 11 according to the swing of the lever cam 15. The link plate 16 includes a claw portion 16b and interlocks with a latch 9 that engages with the cla w portion 16b. A latch receiver 17 and a push plate 18 are arranged inside the latch 9, and a latch spring 10 is arranged in a space surrounded by t he latch receiver 17 and the push plate 18. The latch spring 10 is a compr ession coil spring, which is locked to the base portion 17a of the latch r eceiver 17 and the spring receiver portion 9b of the latch 9, and always u rges the latch 9 and the latch receiver 17.

[0025] In the state of FIG. 2 in which the arm 8 and the latch 9 grip the crossbe am portion 4 of the opened long legs 3, the latch spring 10 urging the lat ch 9 maintain the state of the claw portion 9a to lock the opening 7a. The latch receiver 17 and the push plate 18 are locked to the arm 8 and do no t interlock with the latch 9. By the cooperation of the internal mechanism of the arm 8 starting from the operation by the lever 11, the latch 9 sli des and releases the seat portion 7 as the first step in the crossbeam por tion 4 to which the seat portion 7 is mounted. At this time, the crossbeam portion 4 thus released from the gripping is locked by the arm 8 as shown in FIG. 7.

[0026] FIG. 10 is a cross-sectional view showing a table 2 provided with the long leg fixing device 1 in the present invention, in which the long legs 3 ar e in the middle of closed or opened state. The cutting line is the same as the A-A line of FIG. 2 or FIG. 3. When the lever 11 is further pushed in from the state where the crossbeam portion 4 and the latch 9 are unlocked, the cam pin 14 is locked with the arm 8 as the second step, the lever 11 and the arm 8 start interlocking and moving together. And, the arm 8 swing s around the arm pin 13. Here, in the crossbeam portion 4 to which the sea t portion 7 is mounted, the lock between the arm 8 and the seat portion 7 is released, and the long legs 3 linked to the crosspiece 4 may be closed. The arm pin 13 is inserted into the coil of a torsion coil spring 19 that types as the double torsion. An arm portion of the torsion coil spring 19 is engaged with a spring receiving portion (not shown) of the lever 11, a nd the intermediate portion of the torsion coil spring 19 is engaged with a spring receiving portion 12a of the base 12 to urge the lever 11. Theref ore, the operation of pushing the lever 11 in the direction of the top pla te 5 requires a constant load.

[0027] FIG. 11 is a cross-sectional view taken along the line A-A of FIG. 3 showi ng a table 2 provided with the long leg fixing device 1 in the present inv ention, in which the long leg fixing device 1 locks the crossbeam portion 4 of the closed long leg 3. The long legs 3 that can be closed reach the c losed-leg state of FIG. 11 via the state of FIG. 10. The closed-leg state is maintained by engaging a hang portion 20a of a hook 20 with a base pin 21. The base pin 21 is attached to the base 12. The hook pin 22 attached t o the arm 8 serves as a shaft of the hook 20, and the hook 20 interlocks w ith the swing of the arm 8.

[0028] FIG. 12 is a perspective view of the hook 20. A claw portion 20b of the ho ok 20 engages with the claw receiving portion 16c of the link plate 16. Th e hook 20 moving together the hook pin 22 as the link plate 16 moves in co njunction with the swing of the lever 11. The hook pin 22 is inserted into the coil of a torsion coil spring 23 that types as the double torsion. An arm portion of the torsion coil spring 23 is engaged with a spring receiv ing portion (not shown) of the Arm 8, and the intermediate portion of the torsion coil spring 23 is engaged with a spring receiving portion 20c of t he hook 20 to urge the hook 20. When the long leg 3 is closed and the load of the lever 11 is removed, the hook 20 swings due to the urging of the t orsion coil spring 23 and engages with the base pin 21. When the hook 20 i s engaged with the base pin 21, the arm 8 is fixed to the base 12 and do n ot swing. At this time, the crossbeam portion 4 is locked to the arm 8, an d the long legs 3 do not open.

[0029] FIG. 13 is a cross-sectional view showing the table 2 provided with the lo ng leg fixing device 1 in the present invention, in which the long leg fix ing device 1 is capable of the opening the legs 3 from the state in which the crossbeam portion 4 of the closed long legs 3 are locked. The cutting line is the same as the line A-A in FIG 3. When the lever 11 is operated a nd slightly pushed toward the top plate 5, the lever cam 15 and the link p late 16 are interlocked as the first step, the hook 20 swings, and the hoo k 20 and the base pin 21 are released. When the lever 11 is further pushed in from the state where the hook 20 and the base pin 21 are released, the cam pin 14 is locked with the arm 8 as the second step, the lever 11 and the arm 8 start interlocking and moving together. And, the arm 8 swings ar ound the arm pin 13. Here, in the crossbeam portion 4, the arm 8 swinging in the direction away from the top plate 5 and the crosspiece 4 are releas ed, and the long legs 3 linked to the crosspiece 4 may be opened. The long legs 3 that can be opened reach the opened-leg state of FIG. 4 via the st ate of FIG. 10.

[0030] The arm 8 of the long leg fixing device 1 in the present invention is prov ided with a window 8a that allows the latch 9 to be visually recognized fr om the bottom surface side. Since the latch 9 is interlocked by the operat ion of the lever 11, the portion of the latch 9 that may be visually recog nized from the window 8a differs between when the lever 11 is in the refer ence position and when the lever 11 is in the pushed state. By arranging d ifferent colors at each position, it is possible to operate the entire lon g leg fixing device 1 while checking the operation of the mechanism inside the arm 8.

[0031] Since the long leg fixing device 1 in the present invention grips the cros sbeam portion 4 by the arm 8 and the latch 9, it is not necessary to rely on a strong spring for engaging the crosspiece 4 and the arm 8 to keep the open-leg state. Further, by operating the lever 11, the mechanism enables two-step operation of releasing the fixed state of the long leg 3 as the first step and swinging the arm 8 as the second step, so that only the ope ration of lever 11 may be released the closed-leg state, and the long leg 3 may be easily opened and closed.[Description of the reference numerals]

[0032] 1Long leg fixing device. 2table. 3Long legs. 4Crossbeam portion. 5Top plate. 6Hinge. 7Seat portion. 8Arm. 9Latch. 10Latch spring. 11Lever. 12Base. 13Arm pin. 14Cam pin. 15Lever cam. 16Link plate. 17Latch receiver. 18Push plate. 19Torsion coil spring. 20Hook. 21Base pin. 22Hook pin. 23Torsion coil spring.

Claims

1. A long leg fixing device (1) for a table (2), the table (2) having four long legs (3) and having a structure in which two of the long legs (3) are linked by means of a crossbeam portion (4), and in which said two long legs (3) are fitted to the table (2) in such a way as to be capable of pivoting by means of a hinge (6) to move together to open and close the long legs (3), the long leg fixing device (1) comprising: a base (12) that is fixable to a top plate (5) of the table (2); an arm pin (13) inserted into said base (12); an arm (8) and a lever (11) arranged to swing around the arm pin (13), said lever (11) having a claw portion (11a); a cam pin (14) inserted through said arm (8) and said lever (11) and which is not inserted into the base (12), said cam pin (14) being a common shaft for said arm (8) and said lever (11); a lever cam (15) arranged to swing around said cam pin (14) as a shaft and arranged to engage with the claw portion (11a) of the lever (11), the lever cam (15) including a hanging plate portion (15a) in the center thereof; a latch (9); a link plate (16) including a base portion (16a) and a claw portion (16b) arranged to interlock with the latch (9); a seat portion (7) which is mountable to the crossbeam portion (4) of the table (2), the arm (8) and the latch (9) being configured to grip the seat portion (7); and, a latch receiver (17) and a push plate (18) arranged inside the latch (9), and a latch spring (10) is arranged in a space surrounded by the latch receiver (17) and the push plate (18); wherein the diameter of a pin hole (15b) of the lever cam (15) through which said cam pin (14) is inserted is formed to be slightly larger than the diameter of a body portion of said cam pin (14), and a pin hole (11b) of said lever (11) is formed in the shape of a slot; wherein the lever (11) is operable to cause the hanging plate portion (15a) to come into contact with the base portion (16a) of the link plate (16) and to cause the claw portion (16b) of the link plate (16) to interlock with the latch (9), such that the arm (8) and the latch (9) are interlocked and the link plate (16) is moved in the direction of the lever (11); wherein the latch spring (10) is a compression coil spring, which is locked to the base portion (17a) of the latch receiver (17) and the spring receiver portion (9b) of the latch (9), and always urges the latch (9) and the latch receiver (17); and wherein the lever cam (15) that engages with the claw portion (11a) of the lever (11) swings around the cam pin (14) in response to the swing of the lever (11).

2. A long leg fixing device (1) according to claim 1, wherein the lever (11) is operable to cause the latch (9) to slide and release the seat portion (7) in a first step and the arm (8) to swing to release the lock with the seat portion (7) in a second step.

3. A long leg fixing device (1) according to claim 1, further including: a base pin (21) provided in the base (12); and a hook (20) that is movable with an operative swing of the lever (11) such as to engage the hook (20) with the base pin (21), and wherein the arm (8) is fixable to lock the crossbeam portion (4).

4. A long leg fixing device (1) according to claim 3, wherein by the operation of the lever (11), the hook (20) and the base pin (21) are releasable in a first step and the arm (8) is swingable to release the lock with the seat portion (7) in a second step.