JP4836683B2 - Step for lifting truck bed - Google Patents

Description

  The present invention relates to a step for raising and lowering a truck bed as a ladder used by leaning on a required part of a truck bed.

  The present invention relates to an ascending / descending step for a worker to ascend / descend to / from a loading platform for carrying out work on a loading platform of a truck or to carry a small luggage or the like from the loading platform.

As a step for raising and lowering a truck bed as a ladder dedicated to a truck bed, there is one disclosed in the following patent document as an alternative to an ordinary ladder in which a step bar is attached to a pair of pillars on both sides at appropriate intervals. When a normal ladder is used as it stands on a required part of the truck bed, for example, a cage attached to the platform, other workers other than the worker who goes up and down the ladder because the ladder is easy to slide from the cage. Etc. had to hold the ladder, and it was supposed to be able to safely hold itself without slipping even if it was stood up.
JP 2005-48381 A

As shown in FIG. 15 , the truck elevating ladder A is composed of a ladder 3 in which a pair of struts 1 are horizontally mounted on both sides of a pair of struts 1, 1 and a strut 1 on one side of the ladder 3. It comprises a handrail 4 to be attached, and a latch 6 provided on the upper side of both struts 1 and 1 of the ladder 3 and latched at a standing position of the loading platform 5 of the truck.

  Although not shown in the drawings, each column 1 of the ladder 3 includes a column body and an expansion / contraction member connected to the lower end portion of the column body so that the expansion / contraction can be freely adjusted. A grounding base 9 is provided at the lower end portion of the expansion / contraction member. It is pivotally attached. Anti-slip is applied to the bottom surface of the grounding base 9.

  The latching tool 6 includes a pivotable pivot plate 10 having one end pivotally attached to each column 1 of the ladder 3 and a substantially L-shaped latch body fixed to the tip of the pivot plate. 11, a latch position holding means for holding the latch body 11 at a latch position protruding horizontally forward from the column 1 when the ladder 3 is in a leaning posture with a predetermined inclination angle, and the latch body 11 It is comprised by the retraction position holding means hold | maintained at the retraction position retracted | saved to the support | pillar 1 side.

  The usage method will be described. When using the lift ladder A, when the lift R is tilted on the base end portion 37 of the lift R in a state where the lift R of the truck bed 5 is tilted, the ladder 3 is placed on the ground G. The hook body 11 of the hook 6 is hooked to the base end portion 37 of the lift R pivotally attached to the loading platform 5 while being tilted forward so as to have a predetermined inclination angle.

  Similarly, when the lift R is erected with respect to the loading platform 5 and the lifting ladder A is stood and used on the upper end portion of the handrail 38 standing on the lift R, the latch 6 is similarly latched. The tool body is hooked on the upper horizontal frame of the handrail 38.

In this way, when the lifting ladder A is leaned against a required part of the truck bed part 5 and used, the latching tool 6 provided on the upper side of each of the columns 1 and 1 of the ladder 3 is used to lean the truck bed part 5. 15, in the example of FIG. 15 , the base end portion 37 of the tilting R and the upper horizontal frame of the handrail 38 are hooked and self-held, so that there is no need for the operator to hold the ladder 3, and therefore the lifting ladder No extra workers are required to use A, and the lifting ladder A can be used safely.

  When the load on the truck bed can be lowered to the level when loading or unloading, it can be used as a work space for workers on the lift, which is convenient when loading the entire bed. .

However, in the conventional example shown in FIG. 15 , the latching tool 6 hooks a substantially L-shaped latching tool main body, and the tilt of the truck bed is raised, or it is folded 180 degrees from this standing state. When it was used in a horizontal state, it could not be used because there was no place to catch it.

  The present invention eliminates the inconvenience of the conventional example, and even if the tilt of the truck bed is tilted in a horizontal state, it can be safely held without slipping, and the ladder is used as a support leg for the tilt. An object of the present invention is to provide a step for raising and lowering a truck bed that can support a tilted horizontal tilt and can increase the load receiving strength of the tilt.

In order to achieve the above object, the present invention according to claim 1 is a step for raising and lowering a truck bed as a ladder that is used by leaning on a required place of the truck bed, and a step bar is attached to a pair of columns on both sides at appropriate intervals. Each ladder of the ladder has an upper stretchable part that slidably fits the upper stretchable hook into the pillar main body, and the base of the upper stretchable stick is fixed to both side surfaces of the upper stretchable stick. A base that surrounds the outer periphery of the upper telescopic rod with an upper pressure contact piece that is a fixed piece integrally forming a jaw portion that projects forward and presses against the upper surface of the jaw, and a vertically movable lower pressure contact piece positioned below the upper pressure contact piece In addition, the jaw part that projects to the front of the upper telescopic hook is integrally formed, and it consists of a movable piece with locking means by a ratchet mechanism, and a gripping mechanism that sandwiches the tilted end of the truck bed that has been tilted horizontally from above and below provided was It is an gist and.

According to the first aspect of the present invention, since the upper and lower ends of the truck bed that is horizontally tilted by the gripping mechanism by the press contact pieces sandwiched from above and below provided on each column of the ladder are sandwiched and attached from above and below, As a result, it is possible to support the tilted horizontal tilt, and the ladder can be hung in a stable and stable state, and the load receiving strength of the tilt can be increased. Moreover, since it consists of the movable piece provided with the latching means by a ratchet mechanism, pinching can be implement | achieved reliably.

By making the upper part of the strut an expandable part, the lower end of the strut can be grounded first, the strut itself can be extended, and the sandwiching mechanism can be adjusted to the tilt position. On the contrary, it is also possible to ground the strut lower end by extending the strut itself after the end is sandwiched and the end is sandwiched.

The gist of the present invention described in claim 2 is that the support column has a lower expansion / contraction portion in which a lower expansion / contraction hook is slidably fitted to the support column main body. Further, according to the present invention, a large, substantially square square hole is formed in a column at intervals in the lower telescopic ridge, and the column main body has a locking corner that fits into the square hole. it is an gist that the box-shaped locking member provided with a lower fixing metal fitting formed by biasing by a spring.

According to the second aspect of the present invention, since the support column is the lower telescopic part , the support lower end can be grounded first, the support column itself can be extended, and the sandwiching mechanism can be adjusted to the tilt position. On the contrary, it is also possible to ground the strut lower end by extending the strut itself after the end is sandwiched and the end is sandwiched.

  According to the third aspect of the present invention, the lower telescopic portion and the lower telescopic rod serve as support legs. Therefore, the safety is emphasized, and the locking corner portion of the box-shaped locking member is provided in the large substantially square hole. By fitting, the certainty of locking with respect to the column main body is expected, the locking stage is too fine, and it will not become insufficient.

According to a fourth aspect of the invention, without providing the above gripping mechanism of the upper telescopic rod gripping mechanism Yoko, above the gripping mechanism is for the subject matter to be configured as a key portion when lifting.

According to the fourth aspect of the present invention, there is no need to provide a handrail as in the conventional example, and the upper part of the support column is used as a clue part when moving up and down, so that there is no need for a handrail. Can be moved up and down.

  As described above, the step of raising and lowering the truck bed of the present invention can safely hold itself without slipping even if the truck bed is tilted in the horizontal state, and the ladder supports the cage. As a leg, it will also support the tilt that has been tilted horizontally, and the load receiving strength of the tilt can be increased.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a first embodiment of a step for raising and lowering a truck bed according to the present invention, and FIG. 2 is a front view of the same.

  The step for raising and lowering the truck bed of the present invention includes a ladder 3 in which a plurality of step bars 3a are attached at appropriate intervals between a pair of support columns 1 and 1, and a gripping mechanism 7 for sandwiching the end of the lift R of the truck bed from above and below. Constitute.

  The ladder 3 is composed of a lower telescopic rod 22a that slidably fits the column 1 into a hollow prism-shaped column main body 1a and an upper telescopic ridge 23a that slidably fits into the upper and lower portions of the column 1 at the upper and lower portions. A double-structured stretchable part is provided (lower stretchable part 22, upper stretchable part 23).

  The lower telescopic part 22 and the upper telescopic part 23 include a lower fixing bracket and an upper fixing bracket, which will be described later, for fixing the lower elastic rod 22a and the upper elastic rod 23a to the column main body 1a.

  The inside of the column main body 1a is opened by a slit along the longitudinal direction in order to expose a square hole of the lower telescopic rod 22a and a round hole of the upper telescopic rod 23a, which will be described later.

  Of the upper and lower stretchable parts, the upper stretchable part 23 will be described first. As shown in FIG. 3, a long hole 24 is provided in the vertical direction in the upper elastic bar 23a constituting the upper elastic part 23, and further, round holes 25 are formed in vertical rows at appropriate intervals on the lower side.

  As shown in FIG. 2, the grip mechanism 7 is provided on the upper telescopic rod 23a, and the upper fixing bracket 13 for positioning and fixing the upper telescopic rod 23a inserted and slid from the upper opening is provided on the column main body 1a.

  The upper telescopic rod 23a is formed in a channel shape or a rectangular tube shape, and becomes an inner tube with respect to the column main body 1a as an outer tube, and the corner portions of the four corners protrude outwardly in a rib shape to form a protruding portion 40. The protruding portion 40 and a portion in the vicinity thereof are formed thicker than other side wall portions.

  On the other hand, a groove 41 corresponding to the protruding portion 40 is formed on the inside of the corner portion in the column main body 1a. As a result, a gap 42 is formed between the inner surface of the column main body 1a and the outer surface of the upper expansion rod 23a in a state where the upper expansion rod 23a serving as the inner tube is inserted into the column main body 1a serving as the outer tube. Is done.

  Further, by forming the corner portion of the column main body 1a, that is, the portion corresponding to the protruding portion 40 and the vicinity thereof, the protruding portion 43 is formed outside the portion. Similarly, the protrusion 43a is formed outside the portion by forming the corner of the housing 16 covering the corner of the column main body 1a thick.

  By doing in this way, even if foreign matter such as sand or dust is sandwiched between the column main body 1a and the upper telescopic rod 23a, the foreign matter is discharged through the gap 42, so that no galling occurs, There is no possibility that the telescopic rod 23a will not slide.

  Furthermore, even if a transported object or tool hits the column main body 1a at the work site, it is difficult to deform because the protrusion 43 is formed on the outer corner which is likely to collide and is formed into a thick part. However, since the deformation does not reach the inner upper telescopic rod 23a, the upper telescopic rod 23a does not slide due to the deformation of the column main body 1a.

  When the upper elastic part 23 is pulled out or pushed into the column main body 1a, the protrusion 40 formed on the upper elastic unit 23 is fitted in the groove 41 formed on the column main body 1a. Therefore, the protrusion 40 and the groove 41 act as a guide, and the sliding direction of the upper telescopic rod 23a is restricted. Therefore, the upper telescopic rod 23a can be smoothly slid.

  Although not shown in the drawings, this configuration is the same in the lower telescopic portion 22 by the lower telescopic rod 22a that is slidably fitted to the column main body 1a, and the lower telescopic rod 22a is the upper telescopic rod 23a. It has the same protrusion 40 as that of FIG.

  As shown in FIGS. 5 and 6, the upper fixing bracket 13 includes a locking member 20, a coil spring 14, and a housing 16 that accommodates these and fixes them inside the column main body 1 a.

  The locking member 20 is provided with side wall plates 20d on both side surfaces of a vertically long plate-like spring receiving portion 20e facing the inner side surface of the support column 1 to have a U-shaped cross section, and the upper end of the spring receiving portion 20e is the upper end of the support column 1 The L-shaped lever 18 is bent upwardly after being bent vertically with respect to the inner side surface thereof, and the tip of the L-shaped lever 18 is bent upward, and the spring receiving portion 20e is bolted via a nut 20b. A plurality of stages of engaging protrusions 20a are provided facing outward.

  The housing 16 that accommodates the locking member 20 has a U-shaped cross section so that the side wall plate 20d of the locking member 20 is sandwiched from both outer sides, and both ends thereof are bent along the shape of the column main body 1a. In a state where the main body 1a is sandwiched from the front and rear direction, the main body 1a is fixed to the column main body 1a by the upper and lower screws 30.

  A coil spring 14 having both ends formed in a straight line and having its tip wound further is disposed between the side wall plates 20d of the locking member 20 with both ends facing upward, and one end thereof is a spring receiving portion 20e of the locking member 20. With the other end in contact with the inner side surface of the housing 16, the annular portion is supported by a bolt 32 or a shaft penetrating the housing 16 and the side wall plate 20 d in the left-right direction to lock the coil spring 14. Attach to member 20.

  As shown in FIG. 13, a round hole 25 into which the engaging protrusion 20a is fitted is formed in the upper telescopic rod 23a. The round hole 25 has a plurality of engagement protrusions 20a (two in the drawing), and thus a plurality of round protrusions 25a are provided accordingly. However, the upper telescopic part 23 may be extended only by one step with respect to the column main body 1a. The reason why a plurality of the engagement protrusions 20a are provided is to ensure the locking of the upper stretchable portion 23.

  Next, as shown in FIG. 7, in the lower telescopic portion 22, the lower telescopic ridge 22 a has a relatively large square hole 26 on the inner side surface with a relatively long space (for example, 1. (5 to 2 pieces) are formed in a column, and are provided with a non-slip groove at the lower end, and are further covered with resin leg ends 27 which are inclined to make contact with the ground, and are attached with bolts or the like. And as shown in FIG. 11, the lower fixing | fixed metal fitting 12 which positions and fixes the lower expansion-contraction rod 22a inserted and slid by insertion from the lower opening was provided in the support | pillar main body 1a.

  The lower fixing bracket 12 includes a locking member 21, a coil spring 15, and a housing 17 that accommodates them and fixes them inside the column main body 1 a.

  As shown in FIG. 8, the locking member 21 is formed in a box shape with a U-shaped cross section by providing a side wall plate 21 b on a vertically long plate-like spring receiving portion 21 d facing the inner side surface of the support column 1. The receiving corner 21d is bent at an acute angle so that the lower side is folded inward to form a locking corner portion 21a that fits into the square hole 26, and then is further lowered downward to form the L-shaped lever 19. . A bolt hole 21c is provided on the upper part of the two side wall plates 21b.

  The length and shape of the spring receiving portion 21d are sufficient if the coil spring 15 can stably abut and can hold the side wall plate 21b, and a notch 21e is provided at the center as shown in the figure. Also good. Thereby, the sand etc. which entered in the locking member 21 can be discharged | emitted from the notch 21e outside.

  The housing 16 that accommodates the locking member 21 has a U-shaped cross section so that the side wall plate 21b of the locking member 21 is sandwiched from both outsides, and both ends thereof are bent along the shape of the column main body 1a. With the main body 1a sandwiched from the front-rear direction, the upper and lower sides are screwed to fix the main body 1a to the column main body 1a.

  As shown in FIGS. 9 and 10, the coil spring 15 is formed by forming both ends in a straight line and further bending the tip thereof. The bending direction is the inner direction at the spring receiving portion side end 15a and the width direction of the coil spring 15 at the casing side end 15b.

  The coil spring 15 is disposed between the side wall plates 21 b of the locking member 21 with both ends facing downward, the spring receiving portion side end 15 a is brought into contact with the spring receiving portion 21 d of the locking member 21, and the other end of the housing 17. The coil spring 15 is attached to the locking member 21 with the annular portion supported by a bolt 33 or a shaft penetrating the housing 17 and the side wall plate 21b in the left-right direction in a state of being in contact with the inner side surface.

  A gripping mechanism 7 is provided on each support column 1 in which the lower telescopic part 22 and the upper telescopic part 23 are formed in two places in the upper and lower directions so as to sandwich the end of the lift R of the truck bed that has fallen horizontally. This gripping mechanism 7 is provided on the upper telescopic rod 23a.

  As shown in FIG. 12, the gripping mechanism 7 is composed of an upper press contact piece 28 that is a fixed piece and a vertically movable lower press contact piece 29 located below the upper press contact piece 28.

  The upper pressure contact piece 28 is integrally formed with a base portion 28a that is fixed to both side surfaces of the upper telescopic rod 23a by two upper and lower screws 31 and a jaw portion 28b that projects in front of the upper telescopic rod 23a and presses against the upper surface of the tilt. Constitute.

  The lower pressure contact piece 29 is formed integrally with a base portion 29c that surrounds the outer periphery of the upper telescopic rod 23a and a jaw portion 29d that projects forward of the upper telescopic rod 23a, and the base portion 29c is engaged with the elongated hole 24 of the upper telescopic rod 23a. A matching pin 34 was attached.

  Further, the lower end of the back surface of the base portion 29c protrudes rearward and downward, and the lever 29a moves the lower side of the lower pressure contact piece 29 back and forth. Further, the upper side of the leaf spring 36 that is bent in the opposite direction to each other at two locations is attached to the lower portion inside the back surface of the base portion 29c, and the leaf spring 36 is attached to the recessed step portion 23c provided along the top and bottom of the back surface of the upper telescopic rod 23a. It arrange | positions so that a lower side may be pressed, and it urges | biases the upper expansion-contraction collar 23a and the base 29c lower side mutually. That is, the lower side of the lower pressure contact piece 29 is urged backward by the leaf spring 36.

  Further, the lower surface of the jaw portion 29d is made of a metal plate, and the metal plate is exposed at the end of the upper telescopic rod 23a so that the latching portion 29b is engaged with the ratchet teeth 35 provided on the front surface of the upper telescopic rod 23a. And The ratchet teeth 35 allow the lower pressure contact piece 29 to move downward. The rubber plates 28d and 29e are affixed to the contact surfaces of the upper pressure contact piece 28 and the lower pressure contact piece 29 with the lift of the truck bed so as not to damage the lift.

  The portion above the gripping mechanism 7 of the upper telescopic rod 23a is a portion that functions as a clue portion 23b at the time of raising and lowering, and from the contact surface of the upper press-contacting piece 28 to the tilt R to the upper end of the upper telescopic rod 23a. The length is set to 60 cm or more, and the step bar 3a is not provided in this portion.

  Further, in the portions corresponding to the lower ends of the ratchet teeth 35 on both side surfaces of the upper telescopic rod 23a, the upper telescopic rod 23a will not enter the column main body 1a anymore and the ratchet teeth 35 will not be hidden. A protrusion 39 that contacts the upper end of the main body 1a and functions as a stopper is bolted and attached.

  Next, the operation will be described. First, the upper press-contacting piece 28 is applied to the upper surface of the tilt R of the truck bed that has been tilted horizontally, and the position for applying the lifting step is determined. Thereafter, by pushing the lever 29a, the lower side of the lower pressure contact piece 29 is moved forward against the urging force of the leaf spring 36, and the engagement between the engagement step portion 29b and the ratchet teeth 35 is released. As a result, the lower press-contacting piece 29, which is a movable piece, can be moved up and down along the long hole 24, and the lower press-contacting piece 29 is moved to a position where it comes into contact with the tilt R.

  When the lever 29a is released, the locking step portion 29b is again locked to the ratchet teeth 35, and the lower pressure contact piece 29 is positioned and fixed in a state where the tilt R is sandwiched from above and below by the gripping mechanism 7. The general thickness of the tilt R is 40 mm or more and 60 mm or less, and the length of the long hole 24 is set so that the lower pressure contact piece 29 can move up and down at least within this range.

  Next, the upper stretchable portion 23 and the lower stretchable portion 22 are stretched to adjust the length of the support column 1 according to the height from the ground to the tilt R.

  When the upper telescopic part 23 is expanded and contracted, as shown in FIG. 13, first, the lever 18 of the upper fixing bracket 13 is moved inward against the urging force of the coil spring 14, and the round hole 25 of the upper telescopic bar 23a The engagement with the engagement protrusion 20a is released. Thereafter, the upper telescopic rod 23a is moved up and down with respect to the column main body 1a, and the lever 18 is released when it is moved to an appropriate position.

  As a result, the spring receiving portion 20e is urged toward the support column 1 by the coil spring 14, the engagement protrusion 20a is engaged with the round hole 25 again, and the upper telescopic rod 23a is positioned and fixed with respect to the support column main body 1a.

  When the length adjustment of the column 1 is insufficient only by the expansion / contraction of the upper expansion / contraction part 23, the lower expansion / contraction part 22 is further expanded / contracted, so that the lever 19 of the lower fixing bracket 12 is moved to the coil spring 15 as shown in FIG. It moves to the inner side against the urging force, and the locking of the locking step 21a to the square hole 26 of the lower telescopic rod 22a is released.

  Thereafter, the lower telescopic rod 22a is moved up and down with respect to the column main body 1a, and the lever 19 is released when it is moved to an appropriate position. As a result, the spring receiving portion 21d is urged toward the support column 1 by the coil spring 15, the locking corner portion 21a is again locked into the square hole 26, and the upper telescopic rod 23a is positioned and fixed with respect to the support column main body 1a.

  In this way, the gripping mechanism 7 is easily gripped corresponding to the thickness of the tilting R, and the gripping position is determined by the two stretchable parts (the lower stretchable part 22 and the upper stretchable part 23) provided at the lower part of the gripping mechanism 7. Can be easily adjusted to the height of the tilting R, and can be efficiently mounted with a lifting step.

  In addition, when a person moves on the tilted tilt R when working on the truck bed, the load is supported by the support column 1 via the lower pressure contact piece 29 and the ratchet teeth 35. Can work on.

  Further, since the clasp part 23b does not have the step bar 3a, the step bar 3a is located above the R and does not obstruct the raising and lowering of the step, and it is safe to grasp the clue part 23b having a sufficient length. And it can move up and down smoothly.

It is a whole side view showing a 1st embodiment of a step for raising and lowering a truck bed of the present invention. It is a whole front view showing a 1st embodiment of a step for raising and lowering a truck bed of the present invention. It is a side view of an upper expansion-contraction part. It is a front view which shows an upper fixing metal fitting and its vicinity. It is a cross-sectional top view which shows an upper fixing metal fitting and its vicinity. It is a side view which shows an upper fixing metal fitting and its vicinity. It is a side view of a lower expansion-contraction part. It is a front view of a lower locking member. It is a front view of the coil spring used for a lower fixture. It is a top view of the coil spring used for a lower fixture. It is a front view which shows the lower expansion-contraction part. It is a side view which shows a holding mechanism. It is a front view which shows the state which cancelled | released the lock | rock of the upper fixing metal fitting. It is a front view which shows the state which cancelled | released the lock | rock of the lower fixing metal fitting. It is a whole perspective view which shows the conventional raising / lowering ladder for trucks.

A lifting ladder R tilt G ground 1 strut 1a strut body 2 straddle 3 ladder 3a treadle 4 handrail 5 loading platform 6 hook 7 and 8 gripping mechanism 8a gripping portion 8b upper pressure contact piece 8c lower pressure contact piece 9 grounding base 10 times Moving plate 11 Latch body 12 Lower fixing bracket 13 Upper fixing bracket 14, 15 Coil spring 15a Spring receiving portion side end 15b Casing side end 16, 17 Housing 18, 19 Lever 20 Locking member 20a Engaging projection 20b Nut 20d Side wall plate 20e Spring receiving portion 21 Locking member 21a Locking corner portion 21b Side wall plate 21c Bolt hole 21d Spring receiving portion 21e Notch 22 Lower expansion / contraction portion 22a Lower expansion / contraction hook 23 Upper expansion / contraction portion 23a Upper expansion / contraction portion 23b Catch portion 23c Recessed step portion 24 Long hole 25 Round hole 26 Square hole 27 Resin leg end 28 Upper pressure contact piece 28a Base portion 28b Jaw portion 28d Plate 29 Lower pressure contact piece 29a Lever 29b Locking step portion 29c Base portion 29d Jaw portion 29e Rubber plate 30, 31 Screw 32, 33 Bolt 34 Pin 35 Ratchet tooth 36 Leaf spring 37 Base end portion 38 Handrail 39 Protrusion 40 Protrusion portion 41 Groove Article 42 Clearance 43, 43a Projection

Claims (4)

This is a step for raising and lowering the truck bed as a ladder that is used by leaning on the required part of the truck bed, and each pillar of the ladder formed by attaching stepping bars to the pair of pillars on both sides at an appropriate interval It has an upper expansion / contraction part that slidably fits an expansion / contraction hook,
An upper pressure contact piece that is a fixed piece that integrally forms a jaw portion that protrudes forward of the upper stretchable collar and presses against the upper surface of the tilt, on the base that is fixed to both side surfaces of the upper stretchable collar;
A lower press-contacting piece which is movable up and down located on the lower side thereof, and integrally configured with a base portion surrounding the outer periphery of the upper telescopic fold, a jaw portion projecting forward of the upper telescopic ridge,
It consists of a movable piece with locking means by a ratchet mechanism,
A step for raising and lowering a truck bed, which is provided with a gripping mechanism for sandwiching a tilting edge of a horizontally loaded truck bed from above and below .   The step for raising and lowering the truck bed according to claim 1, wherein the column has a lower expansion / contraction part that slidably fits the lower expansion / contraction hook into the column main body.   A large, substantially square square hole is formed in a row at intervals in the lower telescopic rod, and a box-shaped locking member having a locking corner that fits into the square hole is urged by a spring on the column body. The step for raising and lowering the truck bed according to claim 2, wherein a lower fixing bracket is provided. Gripping mechanism is provided in the middle of the upper telescopic rod, without providing the above gripping mechanism of the upper telescopic rod stepping crosspiece Yoko, it is above the gripping mechanism according to claim 1 to claim configured as a clue portion when lifting 4. The truck bed lifting / lowering step according to any one of 3 above.