JP5378291B2 - Telescopic leg locking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expansion leg device capable of keeping stable operability in a ladder and the like. <P>SOLUTION: In the expansion leg locking device for fixing expansion legs 3 inserted in the lower end portions of supports 1 in a ladder-shaped leg body 10 made by horizontally laying a tread 2 between a pair of the supports 1, 1 so as to have required leg length, an intermediate portion of a locking lever 5 having an engaging tooth 8 engaged with a rack 7 provided in the expansion legs 3 at one end portion, and an operation lever engaging surface 9 on a lower surface on the other end portion side is journaled to a fixing frame 11 fixed to the support 1. A spring 12 is provided, which energizes the locking lever 5 to rotate in a locking direction in which the engaging tooth 8 engages with the rack 7. One end portion of an operation lever 6 is journaled on the other end portion side of the locking lever 5. The operation lever 6 is rotated upward by a predetermined angle from a downward posture in which the other end portion faces downward. The operation lever 6 is further rotated upward while engaging with the operation lever engaging surface 9 of the locking lever 5, thereby rotating the locking lever 5 in a lock-releasing direction to release the locking. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a telescopic leg lock device for fixing telescopic legs provided at a lower end of a series or two or more ladders to a required leg length.

  As a conventional ladder telescopic leg locking device, a publicly known document such as a patent gazette cannot be specifically cited, but a conventional ladder is formed by horizontally placing a foot cross between a pair of struts at appropriate intervals. The locking device for the extendable leg that is inserted into the lower end of each support column has an engagement tooth that engages with a rack provided on the extendable leg at one end, and a lock lever that has an operation portion at the other end. The engaging teeth are arranged so that they point toward the distal end of the telescopic legs, and the middle part of the lock lever is pivotally attached to a bracket fixed to the column, and locked in the direction in which the engaging teeth engage with the rack. The structure is provided with a spring for urging the lever.

  In using this telescopic leg locking device, when extending the telescopic leg, it is only necessary to pull the telescopic leg downward with the lock lever intact, and when contracting the telescopic leg, the other end of the lock lever What is necessary is just to lift a part and rotate it in the direction from which the engagement tooth of the one end part remove | deviates from a rack.

  In the telescopic leg locking device as described above, the lock lever is rotationally biased in the direction in which the engaging teeth at one end thereof engage with the rack on the telescopic leg side by the biasing force of the spring to hold the telescopic leg in the locked state. Therefore, the greater the biasing force of the spring, the stronger the locking lever engagement teeth will engage the rack and maintain a safer and more secure locked state, but the greater the spring force, the more unlocked There is a problem that it is difficult to lift the other end of the lock lever.

  In view of the above circumstances, the present invention can employ a spring having a large spring force on the lock lever side while being easy to lift the operation lever at the time of unlocking, and can achieve a safer and more reliable locked state. An object is to provide a telescopic leg device that can be maintained.

Means for solving the above-described problems will be described with reference numerals in the embodiments described later. The invention according to claim 1 is a horizontal installation of the footpiece 2 between the pair of support columns 1 and 1 at appropriate intervals. In the telescopic leg locking device for fixing the telescopic legs 3 inserted into the lower end portions of the respective pillars 1 in the ladder-shaped leg 10 formed as described above to the required leg length,
An intermediate portion of the lock lever 5 having an engagement tooth 8 that engages with a rack 7 or a continuous hole provided on the telescopic leg 3 at one end and an operation lever engagement surface 9 on the lower surface of the other end is provided on the column 1. A spring 12 is provided for pivotally urging the lock lever 5 in the locking direction in which the engaging tooth 8 engages with the rack 7 or the continuous hole. One end of the operating lever 6 is pivotally attached to the part side, and when the operating lever 6 is rotated in a downward posture with the other end facing downward, it comes into contact with the fixed frame 11 in the unlocking direction of the lock lever 5. A lock lever rotation prevention contact portion 13 for preventing rotation is provided on the outer peripheral portion on one end side of the operation lever 6, and the operation lever 6 is rotated upward by a predetermined angle from the downward posture so that the lock lever 5 is rotated in the unlocking direction. Lock lever 5 in a possible state Has a locking lever engagement surface 14 which engages with the operating lever engaging surface 9, further upward the operating lever 6 in a state the lock lever engagement surface 14 is engaged with the operating lever engaging surface 9 of the locking lever 5 The lock lever 5 is rotated in the unlocking direction to release the lock.

According to a second aspect of the present invention, in the telescopic leg device according to the first aspect, the operation lever 6 is integrally formed of a synthetic resin, and the lock lever is in a downward posture on the one end side of the operation lever 6. 5 is locked to the fixed frame 11 at each of the positions where the rotation in the unlocking direction is prevented and the position where the lock lever 5 can rotate in the unlocking direction by rotating upward from the downward posture by a predetermined angle. A convex piece 17 for holding the lever 6 in position is provided, and this convex piece 17 is adapted to be elastically deformed by being pressed against the fixed frame 11 when the operating lever 6 rotates between both positions. Features.

  The effect of the invention by the above-described solution means will be described with reference numerals of embodiments described later. According to the telescopic leg locking device of the invention according to claim 1, the engaging teeth that engage with the rack 7 or the continuous hole. 8 at one end and an intermediate portion of the lock lever 5 having the operation lever engaging surface 9 on the lower surface on the other end is pivotally attached to the fixed frame 11 fixed to the support column 1, and the engaging teeth 8 A spring 12 is provided for rotating and energizing the lock lever 5 in a direction to engage with the rack 7 or the continuous hole. One end of the operation lever 6 is pivotally attached to the other end of the lock lever 5. Rotating the lock lever 5 in the unlocking direction by rotating the control lever 6 further upward while rotating the control lever 6 in a state of being engaged with the control lever engaging surface 9 of the lock lever 5 from a downward posture. Since the lock is released, the operation lever 6 is a short distance from the fulcrum (pivot part) to the action point (abutment engagement part of the operation lever 6 that abuts and engages the operation lever engagement surface 9 of the lock lever 5). 6), a large force can be applied to the operating point with a small operating force at the operating point of the operating lever 6, so that the operating lever 6 can be easily lifted when the lock is released. On the other hand, the spring 12 having a relatively large spring force can be employed on the lock lever 5 side, and a safer and more reliable locked state can be maintained.

  Since the operation of the operation lever 6 is easy as described above, the operator can perform the unlocking operation by lifting the operation lever 6 even at the instep of the foot. Further, since the operator can easily operate the operation lever 6 at the instep portion of the foot, it is possible to stabilize the telescopic leg 3 while supporting the ladder-like leg with both hands or lifting the ladder-like leg lightly. Telescopic operation can be performed.

  Even if a large external force is applied to the operating lever 6 and the operating lever 6 is damaged or dropped, no force is applied to the locking lever 5 so that the locking lever 5 is damaged. Even if the lock lever 5 is damaged or dropped, the lock lever 5 can be directly operated to release the lock, and the operation lever 6 can be repaired and restored easily.

Further , according to the telescopic leg locking device of the present invention , since the operation lever 6 is attached to the lock lever 5, the operation lever 6 is rotated to a downward posture in which the free end portion is directed downward, thereby operating the operation lever. 6 is brought into contact with the fixed frame 11 to prevent the lock lever 5 from rotating in the unlocking direction, whereby the lock lever 5 is engaged by the spring 12. The lock lever 5 is securely locked in a double lock state of a lock state in which the teeth 8 are engaged and biased to the rack 7 or the continuous hole and a lock state in which the lock state is prevented from being released. can do. Further, the lock lever engaging surface 14 is changed to the operation lever engaging surface 9 of the lock lever 5 in the horizontal posture in which the lock lever 5 can be rotated in the unlocking direction by rotating the control lever 6 upward from the downward posture by a predetermined angle. The lock lever 5 can be easily unlocked by rotating the operation lever 6 further upward while being engaged.

According to the second aspect of the present invention, the operation lever 6 is integrally formed of synthetic resin, and the rotation of the lock lever 5 in the unlocking direction is prevented in the downward posture of the operation lever 6 at the outer peripheral portion of the one end side. The operation lever 6 is locked to the fixed frame 11 at each position of the position and the position where the lock lever 5 is rotated to a horizontal position by rotating upward by a predetermined angle to enable the lock lever 5 to rotate in the unlocking direction. A convex piece 17 for holding the position is provided, and the convex piece 17 is pressed against the fixed frame 11 and elastically deformed when the operating lever 6 rotates between the two positions. By holding the position downward, the operating lever 6 does not shake, so even if the operator's foot touches it, the operating lever 6 does not rotate and avoids unexpected unlocking. Can also by the operating lever 6 is held in place in a horizontal position, it is possible to lock lever 5 now it is confirmed that a single lock state (rotatable locking lever 5 to the unlocked direction state). In addition, when the operating lever 6 is rotated, the clicked piece 17 is elastically compressed and deformed, and an operating feeling can be obtained. It can be confirmed that the state has been switched to.

1 shows a telescopic ladder provided with a telescopic leg locking device according to the present invention, wherein (a-1) is a front view in a contracted state, (a-2) is a side view thereof, and (b-1) is a front view in an extended state. Figure (b-2) is a side view. (a) is an enlarged view of the portion indicated by arrow A in FIG. 1, showing a double lock state in which the operation lever is in a downward posture and the lock lever is prevented from rotating in the unlocking direction, and (b) is (a) (C) is a sectional view taken along line XX of (b). (a) is a view similar to (a) in FIG. 2, showing the state where the operation lever has been rotated a predetermined angle upward from the downward posture and the lock lever can be rotated in the unlocking direction. It is a partially enlarged detail view of a). (a) is a view similar to (a) of FIG. 2, showing a state in which the lock lever is unlocked by rotating the operation lever upward while the lock lever and the engagement surface are in contact with each other, (b) ) Is an explanatory sectional view for further explaining the state of (a), and (c) is a plan view of the part shown in (b). (a) is a front view showing the lock lever in the mounting posture, and (b) is a plan view. (a) is a front view showing the operating lever in a downward position, (b) is a plan view of the operating lever as viewed from arrow B in (a), and (c) is a view of the operating lever from arrow C in (a). FIG. 6D is a partial side view of the semiconductor device viewed from the arrow D in FIG. 5A, and FIG. 5E is a cross-sectional view taken along line EE in FIG. (a) is a front view of a state in which one end of an operation lever is pivotally attached to the other end of the lock lever, (b) is a plan view, and (c) is a left side view. (a) is a front view of the mounting bracket, (b) is a side view, and (c) is a plan view. (a) is a front view of a state in which a lock lever pivotally attached to an operation lever is attached to a mounting bracket, and (b) is a plan view. (a) is a front view of the mounting bracket, (b) is a plan view thereof, and (c) is a right side view thereof. (a) is a front view of the assembled state of the lock lever, operating lever, mounting bracket and mounting bracket, (b) is a plan view of the assembled state, (c) is a right side view thereof, and (d) is a left side thereof. FIG.

  A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a dual-type telescopic ladder provided with the telescopic leg locking device of the present invention. Leg) 10, an upper ladder (ladder-like leg) 20 supported by the lower ladder 10 so as to be movable up and down, a pulley 30 attached to an upper end portion of the lower ladder 10, and one end portion on the upper stage side. An elevator operation rope 40 that is fixed to the lower end of the ladder 20, is mounted on a pulley 30 at the upper end of the lower ladder 10, and the other end is suspended, and the elevator operation rope 40 is operated. Thus, the upper ladder 20 is expanded and lowered along the lower ladder 10.

  Each of the upper and lower ladders (ladder-like legs) 10, 20 is formed by horizontally placing a foot cross 2 between the pair of pillars 1, 1 at an appropriate interval, and each pillar 1 of the lower ladder 10 has a lower end portion. The telescopic legs 3 are slidably inserted into the. The telescopic leg 3 is fixed to a required leg length by the telescopic leg locking device 4 according to the present invention. The telescopic leg locking device 4 is provided below the lowermost step bar 2 of the ladder 10. As shown in FIGS. 2 to 4, a non-slip end tool 31 is attached to the lower end of each column 1.

  As shown in FIGS. 2 to 4, the telescopic leg locking device 4 has an engagement tooth 8 that engages with a rack 7 provided on the telescopic leg 3 at one end and an operation lever on the lower surface on the other end side. An intermediate portion of the lock lever 5 formed with the engagement surface 9 is pivotally attached to a mounting bracket 11 fixed to the column 1 via a fixing bracket 21, and the engagement teeth 8 of the lock lever 5 are engaged with the rack 7. A spring 12 that rotationally biases the lock lever 5 in the direction to be joined is interposed between the lock lever 5 and a mounting bracket (fixed frame) 11, and one end portion of the operation lever 6 on the other end side of the lock lever 5. When the operating lever 6 is rotated to a downward posture with the other end (free end) facing downward as shown in FIGS. 2 (a) and 2 (b), the upper frame portion of the mounting bracket 11 is mounted. A lock that comes into contact with the lower end surface of 11b and prevents the lock lever 5 from rotating in the unlocking direction. A bar rotation preventing contact portion 13 is provided on an outer peripheral portion on one end side of the operation lever 6, and the operation lever 6 can be rotated upward by a predetermined angle from the downward posture so that the lock lever 5 can be rotated in the unlocking direction. In this state, a lock lever engagement surface 14 that engages with the operation lever engagement surface 9 of the lock lever 5 is formed, and this lock lever engagement surface 14 is engaged with the operation lever engagement surface 9 of the lock lever 5. Then, by further rotating the operation lever 6 upward, the lock lever 5 is rotated in the unlocking direction to release the lock.

  The structure of the telescopic leg locking device 4 will be described in more detail. The lock lever 5 is made of an aluminum metal extruded mold formed in a substantially lateral L shape as shown in FIGS. 5 (a) and 5 (b). The engaging tooth 8 that engages with the rack 6 of the telescopic leg 3 is formed at one end, the operation lever engaging surface 9 is formed on the lower surface on the other end side, and substantially at the intermediate portion thereof. A rivet insertion hole 5a through which the lock lever pivot rivet 15 (pivot) shown in FIGS. 2 and 3 is inserted is formed, and an operation lever pivot is provided between the bolt insertion hole 5a and the operation lever engagement surface 10. A rivet insertion hole 5b through which the rivet 16 (pivot) is inserted is formed.

  The operation lever 6 has a shape as shown in FIGS. 6A to 6E, and a rivet insertion hole 6a through which a rivet 16 (see FIGS. 2 and 3) as a pivot is inserted at one end. A lock lever engagement surface 14 that engages with the operation lever engagement surface 9 of the lock lever 5 is formed at the intermediate portion, and a pair of lock lever rotation prevention contact portions on both ends on the outer peripheral portion on one end side. 13 and 13 are formed, and a pair of convex pieces 17 and 17 are formed to be held on the front surface of the flange frame portion 11a of the mounting bracket 11 and hold the operation lever 6 in the downward posture and the horizontal posture described below. . As shown in FIG. 2 (c), the width Wa of the pair of lock lever rotation prevention abutting portions 13, 13 on both sides of the operating lever 6 is made larger than the width Wb of the upper frame portions 11b, 11b of the mounting bracket 11. By forming widely, both the contact parts 13 and 13 can contact | abut to the upper frame parts 11b and 11b at the time of the downward attitude | position of the operation lever 6. FIG.

  FIG. 7 shows a state in which one end of the operation lever 6 is pivotally attached to the lock lever 5 by a rivet 16 (pivot). FIG. 7A shows an operation lever engagement surface 9 of the lock lever 5 in a predetermined mounting posture. The front view of the state which the lock lever engaging surface 14 of the operation lever 6 engaged is shown, (b) is the top view, (c) is a left view.

  8 (a) to 8 (c) show the mounting bracket 11. The mounting bracket 11 is formed from a rectangular tube-shaped rod frame portion 11a and upper end portions of the left and right side walls of the rectangular tube-shaped rod frame portion 11a. It consists of a pair of upper frame portions 11b, 11b on both sides projecting forward and a mounting protrusion 11c projecting from the upper end of the rear side wall of the rectangular tube frame 11a, and the front wall of the square tube frame 11a In addition, openings 18a and 18b through which the lock lever 5 passes are formed in the rear side wall. Also, a rivet insertion hole 19 for inserting a lock lever pivot rivet 15 (pivot) is provided in the upper part of the left and right side walls of the rectangular tubular frame 11a, and the mounting bracket 11 is fixed to the upper and lower ends of the left and right side walls. A bolt insertion hole 23 through which a bolt 25 fixed to the bracket 21 is inserted is provided.

  FIG. 9 shows that the lock lever 5 with the operation lever 6 shown in FIG. 7 is pivotally attached to the rectangular tubular frame 11 a of the mounting bracket 11 by a lock lever pivot rivet 15 (pivot) and the lock lever 5 is engaged. A spring 12 for rotating and energizing the lock lever 5 in a locking direction in which the teeth 8 engage with the rack 7 of the telescopic leg 3 is interposed between the lock lever 5 and the rectangular tubular frame 11 a of the mounting bracket 11. (A) is a front view thereof, and (b) is a plan view thereof.

  10A and 10B show a fixing bracket 21 to which the mounting bracket 11 is attached. FIG. 10A is a front view seen from the front, FIG. 10B is a plan view, and FIG. 10C is a side view. As can be seen from FIG. 2, the fixing bracket 21 includes a fitting frame portion 21 a that is fitted to the lower end portion of the support column 1 and is fixed by the rivet 24, and both upper and lower end portions of both front edge portions of the fitting frame portion 21 a. Is formed by a flange 21b... That is fitted and held by the mounting bracket 11 and fixed with bolts 25 and nuts 26. The locking lever 5 is provided at the center of the front side wall of the fitting frame portion 21a. The engagement teeth 8 at one end are inserted into the respective openings (not shown) of the support column 1 and the telescopic legs 3 to provide openings 27 for engagement with the rack 7, and bolts are inserted into the flanges 21b. A hole 28 is provided. In addition, holes 29 through which the rivets 24 are inserted are provided in the left and right side walls of the fitting frame portion 21a.

  FIG. 11 shows a state where the assembly of the lock lever 5, the operation lever 6 and the mounting bracket 11 shown in FIG. 9 is attached to the mounting bracket 21 shown in FIG. That is, the bolt 25 and the nut 26 inserted through the rivet insertion holes 28 and 28 by fitting the rectangular tubular frame 11 a of the mounting bracket 11 in the state shown in FIG. 9 between the flanges 21 b and 21 b of the fixing bracket 21. The fitting frame portion 21a of the fixed bracket 21 is fitted to the lower end portion of the support column 1 and the mounting protrusion 11c protruding from the upper end of the rear side wall of the rectangular tubular frame frame portion 11a of the mounting bracket 11 is fixed. In the state where it is inserted into the traverse 2, fixing with the rivet 24 inserted into the rivet insertion hole 29 of the fitting frame portion 21 a completes the mounting of all members of the telescopic leg locking device 4. It will be in an attachment state as shown in 2-4.

  The operation of the telescopic leg locking device 4 configured as described above will be described below with reference to FIGS.

  FIG. 2 shows that the operation lever 6 is in a downward posture with the other end portion (free end portion) facing downward, and the lock lever rotation prevention contact portion 13 provided on the outer periphery of the one end side is attached at the position directly above. The double lock state in which the lock lever 5 is prevented from rotating in the unlocking direction is brought into contact with the lower surface of the upper frame portion 11b of the metal fitting 11. In the double lock state, the lock lever 5 is locked so that the engaging teeth 8 are engaged with the rack 7 by the urging force of the spring 12, and the lock lever 5 is locked so as to be prevented from rotating in the unlocking direction. The state that was done. In this double-locked state, the expansion / contraction leg 3 is prevented from moving in the expansion and contraction directions with respect to the column 1, so that it is securely fixed to the column 1.

  That is, the lock lever 5 is only urged by the spring 12 in the direction in which the engaging teeth 8 at one end engage with the rack 7 of the telescopic leg 3. When the force in the direction of pulling up is applied or the telescopic leg 3 is extended against the urging force of the spring 12, the lock lever 5 rotates in the unlocking direction to release the lock. In the double lock state in the downward posture, the lock lever rotation prevention contact portion 13 at the end of the operation lever 6 on the pivot side contacts the lower surface of the upper frame portion 11b of the mounting bracket 11, and the lock lever 5 Since the rotation in the unlocking direction is prevented, the lock lever 5 is completely locked.

  Also, in this double-locked state, the operating lever 6 is in a posture that hangs downward as shown in FIGS. 2 (a) and 2 (b), so that an operator can put his / her foot on the operating lever 6 when using a ladder. There is no risk of catching. Further, as shown in FIGS. 2A and 2B, when the operation lever 6 is in the downward posture in which it hangs down, a pair of left and right convex pieces 17 and 17 projecting from the outer periphery of one end of the operation lever 6 is provided. Is locked to the front surface of the flange portion 11a of the mounting bracket 11 to hold the operation lever 6 in a downward posture. Even if it exists, the operation lever 6 does not rotate inconveniently.

  3 shows that the lock lever 5 is rotated upward by a predetermined angle (for example, about 70 °) from the state where the lock lever 5 is double-locked as shown in FIG. 2, and the lock lever engaging surface 14 of the control lever 6 is locked. A single lock state in which the lock lever 5 can be rotated in the unlocking direction by being brought into contact with the operation lever engaging surface 9 of the lever 5 is shown. In this single lock state, the lock lever rotation prevention contact portion 13 on the outer periphery on one end side of the operation lever 6 rotates downward by a predetermined angle (for example, about 70 °) from the position directly above in the double lock state, The lock lever 5 can be rotated in the unlocking direction because it is away from the contact position with the lower surface of the upper frame portion 11 b of the mounting bracket 11, so that the telescopic leg 3 is in the contracting direction with respect to the column 1. Although it is locked, it can move in the extending direction with respect to the column 1.

  When releasing the double lock as described above, the operation lever 6 is moved from the phantom line illustrated position (double lock position) in FIGS. 3 (a) and 3 (b) to the solid line illustrated position (single lock position) in FIG. ) And a pair of left and right convex pieces 17 and 17 (see FIG. 2 (c)) projecting from the outer periphery of one end of the operation lever 6 are also rotated from the phantom line illustrated position to the solid line illustrated position. The operation piece 6 is held at the single lock position by moving and the convex piece 17 is locked to the front surface of the flange frame portion 11a of the mounting bracket 11 at the position indicated by the solid line. When rotating from the heavy lock position to the single lock position, it is pressed against the front surface of the flange frame portion 11a and is elastically deformed by the compression allowance t as shown in FIG. 3 (b). Then, when the operation lever 6 is rotated, a click feeling that the convex piece 17 is elastically compressed and deformed is obtained, and an operation feeling is obtained. Therefore, the operator switches the lock lever 5 from the double lock state to the single lock state. I can confirm that.

  FIG. 4 shows that the operating lever 6 is rotated further upward from the single locking state as shown in FIG. 3 with the locking lever engaging surface 14 of the operating lever 6 engaged with the operating lever engaging surface 9 of the lock lever 5. In this state, the lock lever 5 is rotated in the unlocking direction and unlocked by adopting the horizontal posture as shown by the solid line in FIG. 4A and the phantom line in FIG. 4B. That is, when the operation lever 6 is further rotated upward, for example, about 20 ° from the state where the lock lever engagement surface 14 and the operation lever engagement surface 9 are in contact, the lock lever 5 resists the biasing force of the spring 12. Rotating in the unlocking direction, the engaging teeth 8 are disengaged from the rack 7 of the telescopic legs 3 to enter the unlocked state, and the telescopic legs 3 can move in either the telescopic direction or the contracting direction with respect to the column 1. It becomes.

  The operation lever 6 is a lever having a fulcrum, a force point, and an action point. The fulcrum is located at one end of the operation lever 6 and is a pivot 16 that is a pivot point with the mounting bracket 11. Is a free end portion of the operation lever 6, and an action point is a lock lever engagement surface 14 that is in contact with the operation lever engagement surface 9 of the lock lever 5, which is close to the pivot 16 that is a fulcrum. Since the distance from the fulcrum to the action point is short and the distance from the fulcrum to the force point is long, the operation force of the operation lever 6 can be reduced. When the lock lever 5 is released by the operation lever 6, the operation lever 6 The lock lever 5 can be easily unlocked by simply pulling up the free end.

  In addition, when the operation lever 6 is in a downward posture at a position along the side surface of the lower end of each column 1, the operation lever 6 is in a double lock position that prevents the lock lever 5 from rotating in the unlocking direction. The lock lever engagement surface 14 of the operation lever 6 is engaged with the operation lever engagement surface 9 of the lock lever 5 in a state in which the lock lever 5 can be rotated in the unlocking direction by rotating about 70 ° upward by a predetermined angle, for example. In addition, by rotating the operation lever 6 further upward by about 20 °, the lock lever 5 is rotated in the unlocking direction to release the lock. The lock lever 5 can be easily unlocked by lifting the free end 6.

  That is, when using a large and heavy ladder-shaped leg product such as the double ladder shown in FIG. 1, the operator can extend and contract while lifting the telescopic leg while supporting the weight of the leg. For telescopic leg locking devices that require operation of the leg locking device and inevitably need to be installed at the lower end of the ladder-shaped leg, operate by bending or tilting the ladder-shaped leg slightly. It is required to perform the expansion / contraction operation by installing only the non-operation side support column and slightly extending the expansion / contraction leg of the operation side support column so that the expansion / contraction operation can be performed. Therefore, if the telescopic leg 3 can be expanded and contracted at the instep portion like the telescopic leg locking device 4 according to the present invention, the operator can support the ladder leg with both hands or the ladder leg. Stable operation is possible even if it is lifted lightly. In particular, it is extremely effective for ladder-like leg products that cannot stand up independently such as ladders.

  2 to 4, the operation lever 6 is matched with the amount of rotation of the lock lever 5 from the downward posture in which the lock lever 5 is double-locked to the lateral posture in which the lock lever 5 is unlocked. However, when the operation lever 6 is in the downward posture where the operation lever 6 is positioned along the flange frame portion 11a of the mounting bracket 11, the lock lever rotation-preventing contact portion 13 at one end of the operation lever 6 is used. Makes contact with the lower surface of the upper frame portion 11b of the mounting bracket 11 to prevent the lock lever 5 from rotating in the unlocking direction, thereby bringing the lock lever 5 into a double-locked state. In such a downward posture of the operation lever 6, there is no fear that an operator will accidentally unlock the device by hooking his / her foot on the operation lever 6 when using a ladder or the like, and the lifting / lowering operation of the telescopic leg 3 will be hindered. There is no such thing.

  Further, since the telescopic leg locking device 4 is installed below the lowermost step rail 2 of the ladder (ladder-like leg) 10, there is no influence on the lifting and lowering of the operator, and the operator's foot is operated by any chance. Unexpected unlocking when the lever 6 is touched can be avoided. Unlike stepladders, etc., where the lower side gradually becomes wider in order to stabilize the work, below the lowermost step rail as a telescopic leg locking device such as a ladder where almost all the step rails are linearly configured with the same width The telescopic leg locking device installed in the door does not obstruct the raising and lowering and is effective for the safe raising and lowering.

  Further, in this telescopic leg lock device 4, even if a large external force is applied to the operation lever 6 and the operation lever 6 is damaged and dropped, the lock lever 5 may be damaged. Even if the operating lever 6 is not damaged and the operating lever 6 is broken or dropped, the unlocking operation can be performed by directly operating the locking lever 5. In addition, the operation lever 6 can be easily repaired and restored.

  Further, the operation lever 6 is integrally formed of synthetic resin, and at one end side outer peripheral portion, a position that prevents the lock lever 5 from rotating in the unlocking direction in the downward posture of the operation lever 6 ((b) in FIG. 3). ), And a position that enables the lock lever 5 to rotate in the unlocking direction by rotating upward from the downward posture by a predetermined angle (the solid line indicated position in FIG. 3 (b)). A convex piece 17 is provided for locking the operation lever 6 at each position to hold the operation lever 6. The convex piece 17 is pressed against the fixed frame 11 when the operation lever 6 rotates between the two positions. Since the operation lever 6 is held in the downward posture, the operation lever 6 is not shaken. Therefore, even if the operator's foot touches, the operation lever 6 Rotate No, it is possible to avoid the lock release of the unexpected. Further, since the operation lever 6 is held in the horizontal posture, it can be confirmed that the lock lever 5 is currently in a single lock state (the lock lever 5 is rotatable in the unlocking direction).

  Further, since the operation lever 6 has a short distance from the fulcrum to the action point and a long distance from the fulcrum to the force point, a large force can be applied to the action point with a small operation force of the operation lever 6. Rotation operation is facilitated while a spring 12 having a relatively large spring force is employed on the lock lever 5 side to maintain a safer locked state.

  In the telescopic leg locking device 4 according to the embodiment described above, the engagement teeth 8 of the lock lever 5 are adapted to engage with the rack 7 provided in the telescopic leg 3. 3, a continuous hole may be provided, and the engaging teeth 8 may be engaged with the continuous hole.

DESCRIPTION OF SYMBOLS 1 Strut 2 Step rail 3 Telescopic leg 4 Telescopic leg lock device 5 Lock lever 6 Operation lever 7 Rack 8 Engagement tooth 9 Operation lever engagement surface 10 Ladder (ladder-like leg)
11 Mounting bracket (fixed frame)
11a Hook frame portion 11b of mounting bracket (fixed frame) Upper frame portion 12 of mounting bracket (fixed frame) Spring 13 Lock lever rotation blocking contact portion 14 Lock lever engaging surface 17 Convex piece 21 Fixed bracket (fixed frame)

Claims (2)

In a telescopic leg lock device for fixing an extensible leg fitted to a lower end of each strut in a ladder-like leg formed by laying a foot cross between a pair of struts at appropriate intervals, to a required leg length,
A fixed frame in which an intermediate portion of a lock lever having an engagement tooth at one end and an operation lever engagement surface on the lower surface of the other end is fixed to the column. And a spring for rotating and energizing the lock lever in a locking direction in which the engaging teeth engage with the rack or the continuous hole, and one end of the operation lever is pivotally attached to the other end of the lock lever. When the operation lever is rotated in a downward posture with the other end facing downward, a lock lever rotation prevention contact portion that contacts the fixed frame and prevents the lock lever from rotating in the unlocking direction is provided on the operation lever. A lock lever provided on the outer peripheral portion of the one end side that engages with an operation lever engaging surface of the lock lever in a state in which the lock lever can be rotated in a unlocking direction by rotating upward from the downward posture by a predetermined angle. Has engagement surface By this locking lever engagement surface rotates further upward the operation lever in engagement with the operating lever engaging surface of the lock lever, made so as to unlock and rotate the lock lever in the unlocking direction Telescopic leg lock device. The operation lever is integrally molded of synthetic resin, and the outer end of one end of the operation lever is rotated at a position that prevents the lock lever from rotating in the unlocking direction when the operation lever is in the downward position, and rotates upward by a predetermined angle from the downward position. A convex piece is provided at each position where the lock lever can be rotated in the unlocking direction to hold the operation lever by locking it to the fixed frame. 2. The telescopic leg lock device according to claim 1, wherein the telescopic leg locking device is configured to be elastically deformed by being pressed against a fixed frame when rotating the arm .

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