JP5409524B2 - Telescopic leg locking device for ladder-like legs - Google Patents

Description

  The present invention relates to an extendable leg locking device for a ladder-shaped leg that extends and contracts a leg (such as a ladder-like leg) such as a stepladder, a ladder, and a work bench and fixes the leg with a predetermined leg length.

  As an example of a conventional ladder-type leg extendable leg locking device, there is one disclosed in Patent Document 1 below. As shown schematically in FIG. 11, the telescopic leg locking device described in Patent Document 1 has a step rail 3 horizontally mounted in a plurality of stages between a pair of left and right columns 2, 2, and expands and contracts at the lower end of each column 2. The above-mentioned telescopic leg 4 of a ladder-like leg formed by inserting the leg 4 so as to be slidable is fixed at a predetermined leg length, and includes a rack 8 provided on the telescopic leg 4 and a lower side step. A lock member 11 that is pivotally mounted in the end portion of the crosspiece 3 and has a tooth 9 that meshes with the rack 8, and has a pocket portion 10 that opens downward on the back of the tooth 9; And an operation member 21 having a protruding piece 29 at the front end that is supported so as to be able to move forward and backward by a fixed stroke only in a horizontal posture along the length direction of the tram and enters the pocket portion 10 of the lock member 11 from below. It is interposed between the member 21 and the end of the step rail 3 Teeth 9 of the locking member 11 is made of a coil spring 22 for urging the operating member 21 in the forward direction to engage the rack 8.

FIG. 11A shows a locked state in which the operation member 21 is urged in the forward direction by the coil spring 22 and the teeth 9 of the lock member 11 are engaged with the rack 8. When the operating member 21 is pulled in the backward direction against the biasing force of the coil spring 22 from this locked state as shown in (b), the locking member 11 rotates counterclockwise with respect to the figure via the protruding piece 29. The teeth 9 move away from the rack 8 and become unlocked. In this unlocked state, the telescopic legs 4 can slide with respect to the column main body 2. When the operation member 21 is returned to the original state in the unlocked state as shown in (b), the locked state as shown in (a) is obtained, and the telescopic legs 4 are fixed to the column main body 2.
JP 2009-121130 A

  In the telescopic leg locking device as described above, since the telescopic leg 4 is a so-called single lock structure that is free in the extending direction, when an operation or impact is applied that moves the stepladder up and down violently when moving, There is a possibility that the extensible leg 4 will be stretched by its own weight, and there is a possibility that the extensible leg 4 will be stretched when the end parts of the extensible leg 4 come into contact with other products during transportation of a stepladder or the like. It was. FIG. 11C shows a state in which the lock member 11 is rotated in the unlocking direction and unlocked by such extension of the telescopic leg 4.

  In view of the above problems, the present invention is such that an operation or an impact is applied such that the stepladder moves up and down violently when the stepladder moves, or the extendable leg is dragged from a state where the stepladder is loaded in a car or the like in multiple stages. An object of the present invention is to provide a telescopic leg locking device for a ladder-like leg that can securely fix the telescopic leg to the column body without causing the telescopic leg to expand even if an operation occurs.

Means for solving the above-described problems will be described with reference numerals in the embodiments described later. Claim 1 includes a plurality of pedestals 3 laid across a plurality of columns between the columns 2, 2. A telescopic leg locking device for fixing the telescopic leg 4 of the ladder-like leg 2 formed by slidingly inserting the telescopic leg 4 into a lower end portion of the leg at a predetermined leg length,
A rack 8 provided on the telescopic leg 4, a lock member 11 that is pivotally mounted in the end portion of the lower-stage side rail 3, has teeth 9 that mesh with the rack 8, and has a pocket portion 10 on the back side of the teeth 9; A high protruding piece 12 that is supported on the side of the step 3 so as to move forward and backward in the length direction, can be lifted at a forward position, and enters the pocket portion 10 from below, and a low position at a lower position. An operating member 15 having a projecting body 14 made of a projecting piece 13 at the front end, a spring 16 for urging the operating member 15 in the forward direction so that the lock member 11 maintains the locked position, and the front side is lifted The operation member 15 includes a locking step portion 18 provided on the side of the traverse 3 so that the low protrusion 13 of the protrusion 14 of the operation member 15 is locked. The lock member 11 is rotated through the piece 12 to release the lock. By pushing up the front side of the operating member 15 when the locking member 11 is in the locked position, with a low projection pieces 13 is engaged with the engaging step portion 18, the low projection pieces 13, pocket 10, the lock member 11 is prevented from rotating by being sandwiched between the front inner wall surface 10 a and the locking step portion 18, thereby locking the lock member 11 double.

  Claim 2 is the telescopic leg locking device of the ladder-like leg according to claim 1, wherein the pocket portion 10 of the lock member 11 includes a front inner wall surface 10a on the side close to the teeth 9 and a rear inner wall surface facing the front inner wall surface 10a. 10b, the front and rear inner wall surfaces 10a, 10b are formed in an upward inclined shape in a direction approaching the tooth 9, and the lower end portion of the front inner wall surface 10a is formed in the vicinity of the entrance of the pocket portion 10. When the operation member 15 is in a horizontal posture, the guide protrusion protruding from the lower end on the front side of the high protrusion 12 of the protrusion 14 is adjacent to the downwardly inclined guide inclined surface 11a in the direction approaching 9. When the portion p is in elastic contact with the downward inclined guide slope portion 11a and the front side of the operating member 15 is pushed up, the guide protrusion p is moved from the downward inclined guide slope portion 11a into the pocket portion 10. Up-tilt front inner wall surface 10a Characterized in that it adapted to migrate to the front inner wall 10a beyond the boundary portion 10o.

  Claim 3 is a lock device in which the lock member 11, the operation member 15, and the spring 16 are attached and fixed in the end portion of the step rail 3 in the ladder-type leg extender locking device according to claim 1 or 2. It is incorporated in the box 19, and the locking step portion 18 is provided at the lower end portion of the lock box 19.

  According to a fourth aspect of the present invention, in the telescopic leg locking device for the ladder-like leg according to the third aspect, the locking step portion 18 provided at the lower end of the lock box 19 has a predetermined length from the rack 8 in the horizontal direction. At least two of the first locking step 18a formed there and the second locking step 18b formed stepwise in the direction away from the rack 8 on the lower side of the first locking step 18a. The at least two types of ladder-shaped leg bodies, each of which includes locking step portions 18a and 18b and differing in the facing angle between the inner side surface of the support column 2 and the upper side surface of the tram 3, the first locking step portion 18a is used, and the second locking step portion 18b is used for one having a large angle.

The effect of the invention by the above-described solving means will be described with reference numerals of embodiments to be described later. According to the invention of claim 1, when the lock member 11 is in the locked position, the front side of the operation member 15 By pushing up, the low protruding piece 13 of the protruding body 14 is locked to the locking step 18 on the side of the tread bar 3, and the low protruding piece 13 is connected to the front inner wall surface 10a of the pocket portion 10. The lock member 11 is prevented from rotating by being sandwiched between the locking step portions 18, thereby preventing the lock member 11 from rotating, and the lock member 11 is double-locked at the lock position. Therefore, even if an operation or an impact is applied such that the stepladder moves up and down violently when moving, or an operation such as dragging the extendable leg 4 from a state where the stepladder is loaded in a multi-stage manner or the like occurs, It ’s not going to grow unexpectedly. The telescopic legs can be securely fixed to the support 2.

  Further, from the state where the lock member 11 is double-locked, the operation member 15 is projected to return to the original posture by simply pulling the operation member 15 away from the rack 8 against the urging force of the spring 16. While the body 14 is descending, the low protrusion 13 is detached from the locking step 18 and the double lock of the lock member 11 is released, and the lock member 11 is released by the high protrusion 12 in the pocket 10. Since the tooth 9 rotates in a direction away from the rack 8 to release the lock, the unlocking operation from the double lock state is easy, and after releasing the lock, if the hand is released from the operation member 15, The operation member 15 can be moved forward by the urging force of the spring 16 to bring the lock member 11 into a normal lock state (single lock state).

  According to the second aspect of the present invention, the operation member 15 can effectively maintain the parallel posture when the lock member 11 is in the normal lock position and is in a projecting shape when the operation member 15 is tilted forward. Since the guide protrusion p of the body 14 is elastically in contact with the front inner wall surface 10a that is inclined upward in the direction approaching the teeth 9, the double lock is released unless the operation member 15 is pulled away from the rack 8. It will be safe. Further, when the guide protrusion p shifts to the upward inclined front inner wall surface 10a in the pocket portion 10 beyond the boundary portion 10o with the upward inclined front inner wall surface 10a which is the top of the downward inclined guide inclined surface portion 11a. Since the operation member 15 has an appropriate click feeling, the double lock state of the lock member 11 can be confirmed.

  According to the third aspect of the present invention, the lock member 11, the operation member 15, and the spring 16 are incorporated in the lock box 19 that is attached and fixed in the end portion of the step rail 3, and the locking step 18 is the lock box 19. Since the lock box 19 only needs to be attached to the step rail 3, the installation of the telescopic leg lock device on the step rail 3 is easy and easy.

  As in the invention according to claim 4, the locking step portion 18 provided at the lower end portion of the lock box 19 includes a first locking step portion 18 a formed at a predetermined length in the horizontal direction from the rack 8. The second locking step portion 18b is formed on the lower side of the first locking step portion 18a in a stepwise manner away from the rack 8, and includes at least two locking step portions 18a and 18b. In at least two types of ladder-like legs with different facing angles between the inner side surface of 2 and the upper side surface of the tread bar 3, the first locking step 18a is used for the smaller one and the larger angle is used. When the second locking step 18b is used, the telescopic leg locking device of the invention according to claim 3 can be used for at least two types of ladder-like legs by one type of component. It is possible to reduce the cost.

It is a perspective view which shows the stepladder used also as a ladder. It is a front view which shows the expansion-contraction leg locking device of this invention applied to the stepladder of FIG. (a) is the sectional view on the AA line of FIG. 2, (b) is the sectional view on the BB line of FIG. (a) is a front view which shows a locking member, (b) is a side view. (a) is a front view of the lock box, (b) is a left side view, and (c) is a bottom view. (a) is a front view of the operating member, (b) is a left side view, (c) is a right side view, (d) is a plan view, (e) is a bottom view, and (f) is a C- It is C sectional drawing. (a)-(d) is explanatory drawing explaining the effect | action of an expansion-contraction leg locking device same as the above. (a) is an enlarged view of a portion indicated by an arrow D in FIG. 7 (a), and (b) is an enlarged view of a portion indicated by an arrow E in FIG. 7 (c). (a) is a front view showing a part of the telescopic ladder, (b) is a side view thereof, and (c) is an enlarged view of a part indicated by an arrow F in (a). It is a front view which shows an expansion-contraction leg locking device. (a) is explanatory drawing which shows the state by which the locking member was double-locked by the expansion-and-contraction leg locking device same as the above, (b) is an enlarged view of the part shown by the arrow G of (b). (a)-(c) is explanatory drawing explaining the effect | action of the conventional telescopic leg locking apparatus.

  A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a stepladder 1 that also serves as a ladder, and FIG. 2 shows a telescopic leg locking device provided on the stepladder 1. The stepladder 1 includes a plurality of steps of a hollow step 3 made of aluminum extruded material, which is horizontally disposed between a pair of left and right hollow columns 2, 2 arranged in a divergent shape made of aluminum extruded material. A ladder-like leg 5 is formed by slidably inserting the telescopic leg 4 into the lower end of the column 2, and the upper ends of the two ladder-like legs 5, 5 are pivotally connected by a rotating metal fitting 6. In order to fix each telescopic leg 4 to a predetermined leg length between the lower end of the column 2 of each ladder-like leg 5, the end of the lowermost step 3A, and the telescopic leg 4. The telescopic leg locking device 7 is provided. The facing angle between the inner side surface of the column 2 of the ladder-like leg 5 and the upper side surface of the step 3 is, for example, 85 ° as shown in FIG. An end cap 35 is attached to the lower end of the column 2 of the ladder-like leg 5. In FIG. 1, one telescopic leg 4 of each ladder-like leg 5 is shown in a contracted state, and the other telescopic leg 4 is shown in an extended state.

  As shown in FIGS. 2 and 3, the telescopic leg locking device 7 is mounted on the rack 8 provided on the telescopic leg 4 and the end of the lower step rail 3 and is engaged with the rack 8. 9 and a locking member 11 formed with an inverted U-shaped pocket portion 10 that opens downward on the back of the tooth 9, and a constant stroke in the horizontal direction in the length direction of the step 3 at the end of the step 3 A protrusion that is supported so as to be able to move forward and backward, has a front portion that can be lifted at the forward movement position, and includes a high protrusion 12 that enters the pocket 10 of the lock member 11 from below and a low protrusion 13 that is positioned lower than this. An operation member 15 having a body 14 at the front end, and is interposed between the rear side of the operation member 15 and the end of the traverse 3, and the teeth 9 of the lock member 11 are engaged with the rack 8. The operation member 15 is urged in the forward direction so as to maintain the lock position. Locking provided on the lower surface side of the end of the traverse 3 so that the coil spring 16 and the low protruding portion 13 of the protruding body 14 of the operating member 15 which is in a forward tilted posture with the front side lifted up are locked. The high protrusion 12 of the protrusion 14 is always in the pocket 10 of the lock member 11 and is locked via the high protrusion 12 by retracting the operation member 15. The member 11 is rotated so that its teeth 9 are disengaged from the rack 8 to release the lock, and when the lock member 11 is in the locked position, the front side of the operation member 15 is pushed up to the forward tilted position. The low projecting portion 13 of the shaped body 14 is engaged with the engaging step portion on the side of the end of the traverse 3 so that the lock member 11 is double-locked at the lock position.

  The structure of the telescopic leg locking device 7 will be described in more detail. As shown in FIGS. 2 and 3, the end portion of the lowermost step rail 3 </ b> A has its end surface close to the inner side surface of the column 2, It is fixed to the column 2 by rivet shafts 20 and 40 which will be described later while being sandwiched between a pair of brackets 37 and 37 attached to both sides of the column 2 with rivets 38 and 38. Further, a lock box mounting opening 39 (see FIG. 3) is cut out on the lower surface of the end of the lowermost step rail 3A, and the lower end portion of the lock box 19 inserted into the end of the step rail 3A. Protrudes downward from the opening 39, and the lock box 19 is fixed in the traverse 3A by the rivet shafts 20, 36, 40.

  As shown in FIGS. 3A and 3B and FIGS. 5A to 5C, the lock box 19 extends downward from the upper wall portion 30 and both side ends of the upper wall portion 30. A pair of upper side wall portions 31, 31 on both sides having a wide facing interval, and a pair of lower side wall portions 33 on both sides having a small facing interval extending downwardly from the lower ends of the upper side wall portions 31, 31 through inward inclined wall portions 32, 32, 33, the lower end 33a of each lower side wall 33 is formed in a cross-section inward L-shape, and a locking step 18 is provided at the front end of the cross-section inward L-shape lower end 33a. Notches are formed. The locking step portion 18 includes a first locking step portion 18a that is a predetermined length in the horizontal direction from the rack 8 in a state where the lock box 19 is attached to the end portion of the lowermost step bar 3A. It is composed of at least two locking step portions 18a, 18b and a second locking step portion 18b formed in a step shape in a direction away from the rack 8 on the lower side of one locking step portion. As will be described later, the portions 18a and 18b are selectively used when the mounting angles of the support column 2 and the traverse 3 are different.

  The rear ends of the lower end portions 33a, 33a of the pair of lower side wall portions 33, 33 on both sides are integrally connected by a connecting piece 34 as shown in FIGS. 5 (b) and 5 (c). A spring receiver 41 for receiving the rear end side of the coil spring 16 protrudes from the piece 34, and the operation member 15 can be slid in the length direction of the treadle on the upper inner surface of each of the lower side wall portions 33 and 33. Guide rails 42 and 42 having an L-shaped cross section that are supported so as to be pushed up are formed. Each upper side wall portion 31 is provided with insertion holes 43, 44, and 45 through which the rivet shafts 36, 20, and 40 are inserted.

  As shown in FIGS. 4A and 4B, the lock member 11 has a hole 47 through which a lock member support tube 46 (see FIG. 3A) fitted on the rivet shaft 36 can be inserted. A plurality of teeth 9 meshing with the rack 8, a pocket portion 10 opened downward so that the projecting body 14 of the operation member 15 enters a portion corresponding to the back side of the teeth 9, and this pocket And a rear protruding piece 17 formed along the rear inner wall surface 10b of the portion 10.

  As shown in FIG. 4 (a), the pocket portion 10 of the locking member 11 includes a front inner wall surface 10a on the side close to the teeth 9 and a rear inner wall surface 10b facing the front inner wall surface 10a substantially in parallel. The front and rear inner wall surfaces 10a and 10b are formed in an upward inclined shape in a direction approaching the teeth 9, and the lower end portion of the front inner wall surface 10a is the entrance of the pocket portion 10 on the lower end surface side of the lock member 11. The guide slope portion 11a, which is formed in the portion and is adjacent to the downwardly inclined guide slope portion 11a in the direction approaching the tooth 9, is located on the front inner wall surface 10a of the pocket portion 10 and outside the pocket portion 10 and is inclined downward. The boundary part (the top part of the downward inclined guide slope part 11a) is denoted by reference numeral 10o in the figure.

  As shown in FIGS. 2, 3, 6, and 7, the operation member 15 has a protruding body 14 that protrudes from below into the pocket portion 10 of the lock member 11 at one end (front end) and the other end. A coil spring holding portion 48 for holding the compression coil spring 16 is provided on the side. As shown in FIGS. 6A to 6F, the protrusions 14 that enter the pocket portion 10 of the lock member 11 have a pair of left and right ends on one end (front end) side of the operation member 15. The low protrusions 13 and 13 and the high protrusions 12 located between the low protrusions 13 and 13 and projecting one step higher than the low protrusions 13 are formed. The guide protrusion p is provided in the left and right horizontal direction at the lower end of the front surface side of 12.

  Further, as shown in FIGS. 6A to 6F, the coil spring holding portion is sandwiched between the projecting body 14 at the front end portion of the operating member 15 and the coil spring holding portion 48 with the both end sides of the high protruding portion 12 interposed therebetween. A pair of support walls 49, 49 that extend continuously so as to form both side walls of the portion 48 are provided, and the lower side wall portions 33, 33 of the lock box 19 are provided at the upper ends of the support walls 49, 49. Support guides 50 and 50 are formed so as to be slidable and supported so as to be slidable by guide rails 42 and 42 formed on the upper surface of the inner surface. Further, a handle step 51 is provided at the lower end of the operation member 15, and a handle 52 is formed in a concave shape on the front end surface of the step 51, that is, the end surface facing the rack 8. On the lower surface of the hand-operated convex step portion 51, an anti-slip concave / convex portion 53 is provided in a direction perpendicular to the sliding direction of the operation member 15, and on both sides of the hand-operated convex step portion 51, An upward arrow mark 54 indicating that the front side of the operation member 15 is pushed up is formed.

  In assembling the lock member 11, the operation member 15, the compression coil spring 16, and the lock box 19, which are constituent members of the telescopic leg lock device 7, first, the lock member 11 is arranged on the distal end side in the lock box 19, and the coil spring As shown in FIGS. 3 (a) and 3 (b), the operation member 15 in which the compression coil spring 16 is housed in the holding portion 48 is connected to the support guides 50 and 50 on the operation member 15 side and the guide rail 42 on the lock box 19 side. 42 and slidably attached to the lower end of the lock box 19, and the high protrusion 12 of the protrusion 14 of the operation member 15 is inserted into the pocket 10 of the lock member 11.

  As shown in FIGS. 2, 3, 5 and 6, the coil spring 16 is housed in the coil spring holding portion 48 of the operating member 15 and the lower side wall portions 33, 33 of the lock box 19. One end of the coil spring 16 is abutted and supported by an end wall 48a (see (a), (d), and (f) of FIG. 6) in the coil spring holding portion 48 with the coil spring 16 being inserted between them. The other end is fitted and held in the spring receiver 41 on the lock box 19 side (see FIGS. 3B and 5C).

  The lock box 19 having the operation member 15 attached to the lower end portion as described above is inserted into the end portion of the lowermost step side rail 3A, and is locked from the lock box mounting opening 39 on the lower surface of the end portion of the step rail 3A. With the lower end portion of the box 19 and the operation member 15 protruding, the rivet shaft 36 fitted with the lock member support pipe 46 (see FIG. 3A) is inserted from the rivet insertion hole (not shown) of the traverse 3A. The lock member 11 is pivotally attached to the lock box 19 and inserted into the rivet insertion hole 43 of the upper side wall portion 31 of the lock box 19 and the hole 47 of the lock member 11, and the rivet shafts 20, 40 are attached. Is inserted through the rivet insertion holes 44 and 45 of the upper side wall 31 of the lock box 19 from the rivet insertion holes (not shown) of the bracket 37 and the traverse 3A. As a result, the assembly of the telescopic leg locking device 7 is completed.

  The telescopic leg locking device 7 in the state of being assembled in this way is shown in FIGS. 2, 3, 7 and 8. In these states shown in FIG. 2, the lock member 11 is fitted on the rivet shaft 36. The lock member support tube 46 (see FIGS. 3 and 8) is pivotable, and is normally moved forward by the compression coil spring 16 as shown in FIGS. 7 (a) and 8 (a). The teeth 9 are held in a locked position where the teeth 9 are engaged with the racks 8 of the telescopic legs 4 by being pushed by the projecting body 14 of the operating member 15 to be urged. At this time, the operation protrusion 15 has a guide protrusion p at the lower end on the front side of the high protrusion 12 of the protrusion 14 protruding into the pocket 10 of the lock member 11 as shown in FIG. As shown in FIG. 3, the support guide 50 is elastically contacted with the downwardly inclined guide slope portion 11a formed on the back side of the lock member 11, so that the support guide 50 is supported by the guide rail 42 (see FIG. 3) in a horizontal posture. It can be maintained effectively.

  When releasing the lock state of the lock member 11, as shown in FIG. 7 (b), the user holds the operation member 15 by placing a hand on the handle portion 52 formed on the handle protrusion 51 of the operation member 15. When pulled in the direction away from the rack 8 against the urging force of the compression coil spring 16 (in the direction of the arrow in the figure), the high protrusion of the protrusion 14 of the operating member 15 that has entered the pocket portion 10 of the lock member 11. When the shaped portion 12 hits the rear protruding piece 17 of the locking member 11 which is the rear inner wall surface 10b of the pocket portion 10, the locking member 11 is rotated counterclockwise with respect to FIG. Detaches from the rack 8 and unlocks the lock member 11. After releasing the lock, if the hand is released from the handle 52 of the operation member 15, the operation member 15 is moved forward in a horizontal posture by the urging force of the coil spring 16, and the lock member 11 is normally moved as shown in FIG. Return to the locked position.

  Then, when the operating member 15 is in the horizontal position as shown in FIG. 7 (a), the front side of the operating member 15, that is, the lower end of the portion with the arrow mark 54 shown in FIG. When pushed up strongly, the guide protrusion p of the projecting body 14 moves the apex portion 10o of the downwardly inclined guide slope portion 11a of the lock member 11 as shown in FIG. 7 (c) and FIG. 8 (b). It moves to the front inner wall surface 10a in the upward inclined shape (upward inclined shape approaching gradually toward the teeth 9) in the pocket portion 10 of the lock member 11, and is elastically contacted with the upward inclined front inner wall surface 10a. The low protruding portion 13 of the body 14 is engaged with the first engaging step portion 18a of the engaging step portion 18 provided in the lock box 19, and the lock member 11 is double-locked at the lock position.

  The state at this time will be further described with reference to FIGS. 8A and 8B. First, the operating member 15 is tilted forward by strongly pushing up the front side of the operating member 15 in a horizontal posture. After the guide protrusion p of the projecting body 14 exceeds the top part 10o of the descending inclined guide slope part 11a while retreating slightly against the coil spring 16 in the posture, the guide protrusion p of the coil spring 16 Due to the urging force, it moves to the upward inclined front inner wall surface 10 a in the pocket portion 10, and the high protruding portion 12 of the protruding body 14 enters the inner depth of the pocket portion 10 and the low protruding portion 13 is locked. The box 19 is locked to the first locking step 18a. At this time, the low protruding portion 13 of the protruding body 14 is sandwiched between the front inner wall surface 10a of the pocket portion 10 and the first locking step portion 18a, thereby preventing the lock member 11 from rotating. Therefore, the lock of the lock member 11 cannot be released even if the extendable leg 4 is pulled out downward. That is, the lock member 11 in the lock position is double-locked by further locking with the low protrusion 13 of the protrusion 14 locked to the first locking step 18a of the lock box 19. Therefore, it is impossible to pull out the telescopic leg 4 by pulling it downward. In addition, when the guide protrusion p passes over the top 10o of the downward inclined guide slope 11a and moves to the upward inclined front inner wall surface 10a in the pocket portion 10, an appropriate click feeling is generated on the operation member 15, so that the lock is locked. The double lock state of the member 11 can be confirmed.

  7 (c) and FIG. 8 (b), the operation member 15 is tilted forward and the lock member 11 is double-locked by the low protrusion 13 of the protrusion 14 from the state shown in FIG. When the operating member 15 is pulled in the direction away from the rack 8 against the urging force of the coil spring 16 (the arrow direction in the figure), the operating member 15 is moved as shown in FIG. While the projecting body 14 descends to return to the horizontal posture from the forward tilted posture, the low projecting portion 13 is detached from the first locking step portion 18a of the lock box 19, and the double lock of the lock member 11 is achieved. After the release, the high protruding portion 12 in the pocket portion 10 hits the rear inner wall surface 10b of the pocket portion 10 to rotate the lock member 11, and as shown in FIG. And the operation member 15 returns to the horizontal posture. Then, after releasing the lock, if the hand is released from the handle 52 of the operation member 15, the operation member 15 moves forward in a horizontal posture by the urging force of the coil spring 16, and the lock member 11 is ) And the normal lock position as shown in FIG.

As described above, according to the telescopic leg locking device 7, when the operation member 15 is in the horizontal posture and the lock member 11 is in the lock position, the front side of the operation member 15 is pushed up to the forward tilt posture. Thus, the low protruding portion 13 of the protruding body 14 is inserted into the pocket portion 10 of the lock member 11 and is locked to the locking step portion 18 of the lock box 19 so that the lock member 11 is doubled to the locked position. Because it is locked, the ladder-like leg does not swing unexpectedly when the ladder-like leg is shaken during transportation of the stepladder, or the stepladder is dragged from a state where it is loaded in a multi-stage, etc. 4 can be securely fixed to the column main body 2.

  Further, in this telescopic leg locking device 7, the pocket portion 10 of the lock member 11 has a front inner wall surface 10a on the side close to the teeth 9 and a rear inner wall surface 10b facing substantially parallel to this, Both the front and rear inner wall surfaces 10a and 10b are formed in an upward inclined shape in a direction approaching the tooth 9, and a lower end portion of the front inner wall surface 10a is formed in the direction approaching the tooth 9 formed near the entrance of the pocket portion 10. When the operation member 15 is in a horizontal posture adjacent to the downward inclined guide slope portion 11a, the guide protrusion p projecting from the lower end on the front side of the high protrusion 12 of the protrusion 14 is provided. The guide protrusion p is lifted in the pocket portion 10 from the downward inclined guide slope portion 11a by pushing up the front side of the operating member 15 while being in elastic contact with the downward inclined guide slope portion 11a. Boundary with inclined front inner wall surface 10a Since it moves to the front inner wall surface 10a beyond 10o, the operation member 15 can effectively maintain the parallel posture when the lock member 11 is in the normal lock position and the operation member 15 is When the forward inclined posture is adopted, the guide protrusion p of the projecting body 14 is elastically in contact with the front inner wall surface 10a inclined upward in the direction approaching the teeth 9, so that the operation member 15 is moved rearward, that is, from the rack 8. As long as it is not pulled away, the double lock is not released and it is safe. In addition, when the guide protrusion p passes over the top 10o of the downward inclined guide slope 11a and moves to the upward inclined front inner wall surface 10a in the pocket portion 10, an appropriate click feeling is generated on the operation member 15, so that the lock is locked. It can be confirmed that the member 11 is in the double locked state.

  Further, in this telescopic leg locking device 7, a handle 52 is formed on the end surface on the side facing the rack 8 on the handle step 51 of the operation member 15. If pulled, the unlocking operation of the operation member 15 can be easily and easily performed.

  Further, according to the telescopic leg lock device 7, the lock member 11, the operation member 15 and the spring 16 are incorporated in the lock box 19 which is attached and fixed in the end portion of the step rail 3A, and the locking step portion 18 is locked. Since it is formed at the lower end of the box 19, it is easy to install the telescopic leg locking device for the step rail 3A, and it is easy to attach the column 2 and the step rail 3A. In the embodiment described above, the telescopic leg locking device is installed on the lowermost step rail 3A, but is not limited to the lowermost step rail 3A, and is installed on the second step rail 3 from the lowermost step. Also good.

  FIG. 9 shows an embodiment in which the telescopic leg locking device of the present invention is applied to an telescopic ladder. (A) is a front view showing a part of the telescopic ladder, (b) is a side view thereof, and (c) is ( It is an enlarged view of the part shown by the arrow F of a), It is an external appearance front view which shows the expansion-contraction leg locking device 7 which concerns on this invention. This telescopic ladder is constructed by horizontally laying a hollow step 3 between a pair of left and right hollow struts 2 and 2 parallel to each other, and slidably fitting telescopic legs 4 to the lower ends of the respective struts 2. The lower-stage ladder-like leg body 5A and the upper-stage ladder-like leg body 5B, each of which is formed by horizontally laying a hollow step rail 3 in a plurality of stages between a pair of left and right hollow struts 2, 2 that are parallel to each other, are operated. It is slidably connected up and down via a rope and pulley (not shown). Between the lower end of the column 2 of the lower ladder-like leg 5A, the end of the lowermost step rail 3A and the telescopic leg 4 Further, a telescopic leg locking device 7 for fixing each telescopic leg 4 to a predetermined leg length is provided. The opposing angle between the inner side surface of the support column 2 of the lower ladder-like leg 5A and the upper side surface of the traverse 3A is 90 ° as shown in FIG. 9 (c).

  The telescopic ladder locking device 7 of the telescopic ladder illustrated in FIG. 9 is exactly the same as the telescopic leg locking device of the ladder and stepladder described above, and the description of the structure and operation is omitted, but in the case of this telescopic ladder As shown in FIGS. 10A and 10B, when the locking member 11 is double-locked by pushing up the front side of the operating member 15, the low protruding portion 13 of the protruding body 14 is locked. The second locking step portion 18b of the step portion 18 is locked.

  That is, the angle between the support column 2 and the step 3 is different between the stepladder with the extendable legs 4 and the ladder with the extendable legs 4. In the case of the stepladder with the extendable legs 4 shown in FIG. For example, in the case of the ladder with telescopic legs 4 shown in FIG. 9, the pair of left and right support columns 2 and 2 are parallel to each other. The opposing angle with the side surface is 90 °. Therefore, generally, as in the device according to the present invention, the lock member 11, the operation member 15, and the spring 16 are incorporated into the lock box 19, and the locking step 18 is formed at the lower end of the lock box 19. In the case of the telescopic leg lock device 7 configured by doing this, since it is necessary to set a lock position suitable for each, two types of telescopic leg lock devices with different setting positions of the locking step portions 18 are required. .

  Therefore, in the telescopic leg locking device 7 according to the present invention, the locking step portion 18 provided at the lower end portion of the lock box 19 is fixed in the horizontal direction from the rack 8 as shown in FIGS. A first locking step portion 18a formed at a length, and a second locking step portion 18b formed in a step shape in a direction away from the rack 8 on a lower side of the first locking step portion 18a. The first and second locking step portions 18a and 18b are separately used as a stepladder with an extendable leg 4 and a ladder with an extendable leg 4 when the angles of the support column 2 and the traverse 3 are different. Thus, the first locking step 18a is used for a stepladder with an extendable leg 4, and the second locking step 18b is used for a ladder with an extendable leg 4 as shown in FIG.

  Comparing the case of the stepladder with the extendable leg 4 with the facing angle between the inner side surface of the support column 2 and the upper side of the tram 3 being 85 ° and the case of the ladder with the extendable leg 4 having the facing angle of 90 °, In this case, as shown in FIG. 9, the column 2 is perpendicular to the horizontal plane. In the case of a stepladder, the column 2 is inclined inward, and the rack 8 is also inclined inward. The inclination of the front and rear inner wall surfaces 10a, 10b of the pocket portion 10 of the member 11 can be understood by comparing FIG. 8 (b) and FIG. 10 (b) in the case of a ladder (FIG. 10 (b)). Is larger than that of the stepladder 2 ((b) of FIG. 8). Then, when the lock member 11 is double-locked, the height of protrusion when the high protrusion 12 of the protrusion 14 protrudes into the pocket 10 is the same as in the case of a ladder ((b) in FIG. 10). Is lower than that of the stepladder 2 (FIG. 8B). Therefore, in the case of the ladder, the locking step portion 18 to which the low protruding portion 13 of the protruding body 14 is locked is the case of the stepladder 2. Since the first locking step portion 18a to be used cannot be locked, the second locking step portion 18b is positioned at a lower step of the first locking step portion 18a in a stepwise direction away from the rack 8. In the case of a ladder, the low protrusion 13 of the protrusion 14 is engaged with the second engagement step 18b to double lock the lock member 11.

  In this way, the latching step portion 18 includes the first latching step portion 18a used in the case of the stepladder 2 and the second latching step portion 18b used in the case of the ladder. It can be done by type, and the cost can be reduced. In this embodiment, the locking step portion 18 is composed of the first and second locking step portions 18a and 18b. However, three or more locking step portions are provided with the previous locking step portion. It can be formed in a step shape in a direction away from the rack 8 below the section.

DESCRIPTION OF SYMBOLS 1 Stepladder 2 Strut 3 Step rail 3A Bottom step rail 4 Telescopic leg 5 Ladder-like leg 7 Telescopic leg lock device 8 Rack 9 Teeth 10 Pocket part 10a Front inner wall surface 10b Rear inner wall surface 11 Lock member 12 High protrusion of projecting body Projection part 13 Projection body low projection part 14 Projection body p Projection body guide protrusion 15 Operation member 16 Coil spring 18 Engagement step part 18a First engagement step part 18b Second engagement step part 19 Lock box

Claims (4)

A telescopic leg locking device that fixes a telescopic leg of a ladder-like leg body with a predetermined leg length by horizontally placing a step rail between both struts in a plurality of stages and slidably inserting an extensible leg into the lower end of each strut. There,
A rack provided on the telescopic legs; a locking member that is pivotally attached to the end of the lower-side step rail, has teeth that mesh with the rack, and has a pocket portion on the back side of the teeth; A projecting body consisting of a high projecting piece that is supported so as to move forward and backward in the length direction, can be lifted at a forward position, and projects into the pocket portion from below and a low projecting piece located at a lower position at the front end portion. The operation member having the spring, the spring for urging the operation member in the forward direction so that the lock member maintains the lock position, and the low protrusion piece of the protrusion of the operation member raised on the front side is locked. It consists of a locking step provided on the side of the step crossing, and by reversing the operation member, the lock member is rotated via the high protruding piece to unlock, and operated when the lock member is in the lock position. By pushing up the front side of the member, the low protrusion of the protrusion The so engaged with the engaging step portion, the low projection pieces are brought into a state of being sandwiched by the front inner wall surface and the engaging step portion of the pocket portion, the rotation of the lock member is prevented, whereby A telescopic leg locking device for a ladder-like leg that double locks a locking member.
  The pocket portion of the lock member has a front inner wall surface on the side closer to the teeth and a rear inner wall surface facing the front inner wall surfaces, and both the front and rear inner wall surfaces are formed in an upward inclined manner in a direction approaching the teeth. The lower end portion of the wall surface is adjacent to the guide slope portion that is formed near the entrance of the pocket portion and is inclined downward toward the teeth, and when the operating member is in a horizontal posture, the high projecting piece of the projecting body When the guide ridge protruding from the lower end on the front side is in elastic contact with the downward inclined guide slope, the guide ridge is lowered by pushing up the front side of the operating member. The expansion / contraction leg locking device for a ladder-like leg according to claim 1, wherein the leg is moved from the slope portion to the front inner wall surface over the boundary with the upward inclined inner wall surface in the pocket portion.   The lock member, the operation member, and the spring are incorporated in a lock box that is attached and fixed in an end portion of the step rail, and the locking step portion is provided in a lower end portion of the lock box. Item 3. The expansion / contraction leg locking device for a ladder-like leg according to item 1 or 2.   The locking step provided at the lower end of the lock box includes a first locking step formed at a predetermined length in the horizontal direction from the rack, and a lower side of the first locking step. At least two types of ladders having at least two locking step portions with a second locking step portion formed stepwise in a direction away from the rack and having different facing angles between the inner side surface of the support column and the upper side surface of the step rail The ladder-like leg according to claim 3, wherein a first locking step portion is used for a small leg and a second locking step portion is used for a large angle. Body telescopic leg lock device.

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