Novel retractable mortar box

Abstract

The invention belongs to the technical field of mortar collecting equipment for constructional engineering, and particularly relates to a novel retractable mortar box which comprises waterproof cloth and four supporting columns arranged on the periphery of the waterproof cloth and arranged in a rectangular shape in the horizontal plane. The four supporting columns are jointly and fixedly supported on the outer surface of the waterproof cloth to form a rectangular containing container, a plurality of reinforcing ribs are fixedly connected to the inner side surface of the containing container, a vertical reinforcing column is arranged between every two supporting columns, and a telescopic assembly is hinged between each reinforcing column and the adjacent supporting column; the telescopic assembly comprises a first connecting rod and a second connecting rod, a connecting block is arranged between each supporting column and the corresponding reinforcing column, and the telescopic assembly further comprises a limiting piece which is coaxially and rotationally connected to the hinged position of the first connecting rod and the second connecting rod. The periphery of the waterproof cloth cannot be effectively supported under the condition that the folding of the waterproof cloth is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of mortar collecting equipment for construction engineering, and in particular relates to a novel retractable mortar box. Background Art

[0002] During the construction process, it is usually necessary to stir the mortar on site to fully mix the cement, water, sand and other additives to improve the hydration of cement particles, thereby improving the strength and durability of the mortar. Stirring can help remove bubbles in the mortar, reduce porosity, and improve the density and strength of the mortar. After stirring, the mortar generally needs to be transported using tools. For example, a Chinese patent discloses a movable premixed mortar storage box (patent announcement number: CN214084294U), including a rectangular flatbed truck with casters and handrails, and square woods perpendicular to the flatbed truck are fixed at the four corners and the middle of the long side of the flatbed truck. The side of the square wood is provided with grooves that penetrate the square wood, and baffles are inserted between the grooves of adjacent square woods so that the baffles form a box body on the flatbed truck that is closed on all sides and separated in the middle. The function of simultaneously transporting dry-mixed mortar and mixed mortar can be realized, and the storage capacity is large. The height of the baffle can be adjusted according to the actual needs of the site to increase the capacity.

[0003] Although the above technical scheme can solve the current problem of mortar transportation, in the actual construction process, in order to facilitate the mixing of mortar, most construction workers usually mix the mortar directly on the ground on site, without protection around, and cannot effectively prevent the loss of mortar water. Even if the mortar is mixed in a mortar box, it cannot be used in a turnover manner (most mortar boxes are assembled from waste templates), and the dead weight is large and transportation is difficult. For this reason, we have previously proposed a scheme of using waterproof cloth as a mortar container, but in actual use, we found that when the mortar is accumulated in the container composed of waterproof cloth, the mortar will continue to squeeze the surface of the waterproof cloth due to its own weight, and the columns used to support the waterproof cloth cannot support most of the outer surface of the waterproof cloth. Over time, the mortar cloth will be severely deformed, which not only affects the stability of the waterproof cloth during use and the efficiency of mortar mixing, but also causes the mortar cloth to occupy a larger area after folding (compared with the mortar cloth without deformation). Therefore, it is necessary to support the mortar cloth on all sides to prevent it from deforming. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a novel retractable mortar box for solving the problem that when waterproof cloth is currently used as a container for mortar mixing, it is not possible to effectively support the surrounding areas of the waterproof cloth while ensuring that it is folded.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A novel retractable mortar box comprises a waterproof cloth for containing mortar and support columns arranged around the waterproof cloth, wherein the support columns are provided with four pieces and are arranged in a rectangular shape in a horizontal plane, wherein each of the support columns is arranged vertically, and the four support columns are fixedly supported on the outer surface of the waterproof cloth together to form a rectangular containing container, wherein the inner surface of the containing container is fixedly connected with a plurality of vertical reinforcing ribs, and the plurality of reinforcing ribs are arranged at intervals in a rectangular shape, and vertical reinforcing columns are provided between two support columns arranged along the length direction of the containing container, and a telescopic assembly is hinged between each reinforcing column and an adjacent support column, and the telescopic assembly comprises a first connecting rod and a second connecting rod of equal length and hinged to each other, and the first connecting rod has a The free end is hinged to the adjacent support column, the free end of the second connecting rod is hinged to the adjacent reinforcement column, and the first connecting rod and the second connecting rod together form a "V" shape, and a connecting block vertically fixed to the outer surface of the waterproof cloth is provided between each of the support columns and the reinforcement columns. The telescopic assembly also includes a limiter coaxially and rotatably connected to the hinge of the first connecting rod and the second connecting rod, and the limiter is slidably arranged on the vertical axis of the connecting block along the vertical direction; a plurality of steel ropes are connected between the two support columns arranged along the width direction of the containing container, and both ends of each of the steel ropes are fixed on the surfaces of two adjacent support columns, and when the containing container is extended to its maximum volume, the surface of each of the steel ropes is against the outer surface of the waterproof cloth.

[0007] Furthermore, each of the connecting blocks corresponds to and is fixedly connected to the adjacent reinforcing ribs, and two telescopic components are hinged between each of the supporting columns and the reinforcing columns, and the two telescopic components are mirror-imaged about the vertical center of the reinforcing column, wherein each of the telescopic components is hinged to the adjacent reinforcing columns and support columns, and the limiting parts in each of the telescopic components are slidably set along the vertical direction on the vertical axis of the connecting block.

[0008] Furthermore, in any two telescopic assemblies arranged in a mirror image, two adjacent first connecting rods are hinged to each other and can be slidably connected along their length direction, and two adjacent second connecting rods are hinged to each other and can be slidably connected along their length direction.

[0009] Furthermore, two slide grooves are provided on the surface of each connecting block, and the two slide grooves are symmetrically arranged about the axis in the width direction of the connecting block, and the center line of each slide groove in the length direction coincides with the center line of the length direction of the connecting block. The limiting member includes a limiting rod and a slider threadedly connected to one end of the limiting rod, and the slider is slidably arranged in each slide groove, and the limiting rod is coaxially and rotatably connected to the hinge of the first connecting rod and the second connecting rod.

[0010] Furthermore, the inner surface of the waterproof cloth is connected with a plurality of connection strips corresponding to the support columns and the reinforcement columns respectively, and each of the connection strips is vertically arranged and fixedly connected to the adjacent support columns and the reinforcement columns by bolts.

[0011] Furthermore, the outer surface of each of the steel wire ropes is sleeved with a plurality of fixed sleeve strips arranged at intervals, and each fixed sleeve strip is fixedly connected to the outer surface of the waterproof cloth.

[0012] Furthermore, the bottom end of each of the support columns and reinforcement columns can be detachably connected to a base.

[0013] The beneficial effects of the present invention are:

[0014] 1. The present invention supports and shapes the waterproof cloth by arranging four vertical support columns on the peripheral side surface thereof, and arranging a reinforcing column between any two adjacent support columns with a large spacing to improve the stability of the waterproof cloth, and two telescopic components mirrored about the horizontal plane are also arranged between the reinforcing column and the support column, which not only further improves the stability of the waterproof cloth, but also effectively improves the convenience effect when the waterproof cloth is unfolded or retracted, and a plurality of spaced and vertical reinforcing ribs are also arranged inside the waterproof cloth to improve the deformation resistance of the waterproof cloth, and combined with structures such as steel wire ropes and telescopic components, it can effectively support and stabilize the surrounding areas of the waterproof cloth, and ensure that the folding of the waterproof cloth can be realized normally.

[0015] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0017] Figure 1 The structure of the waterproof cloth of the present invention is shown as follows: Figure 1 ;

[0018] Figure 2 The structure of the waterproof cloth of the present invention is shown as follows: Figure 2 ;

[0019] Figure 3 It is a side view of the waterproof cloth of the present invention when it is unfolded to its largest size;

[0020] Figure 4 A top view of the waterproof fabric of the present invention when it is unfolded to its largest size;

[0021] Figure 5 It is a schematic diagram of the structure of the telescopic assembly of the present invention.

[0022] The following are marked in the accompanying drawings:

[0023] 1 waterproof cloth, 2 support column, 3 reinforcement rib, 4 reinforcement column, 5 telescopic component, 501 first connecting rod, 502 second connecting rod, 6 connecting block, 7 limiter, 8 wire rope, 9 slide groove, 10 slider, 11 connecting strip, 12 fixed sleeve strip, 13 base, 14 limit rod. DETAILED DESCRIPTION

[0024] like Figure 1 to Figure 5 As shown,

[0025] A novel retractable mortar box comprises a waterproof cloth 1 for containing mortar and support columns 2 arranged around the waterproof cloth 1, wherein the support columns 2 are provided with four pieces and are arranged in a rectangular shape in a horizontal plane, wherein each of the support columns 2 is arranged vertically, and the four support columns 2 are fixed together on the outer surface of the waterproof cloth 1 and are used to support the waterproof cloth 1, so that the waterproof cloth 1 forms a rectangular containing container (the containing container is another name for the waterproof cloth 1 unfolded to a rectangular state), each of the support columns 2 is made of stainless steel material and is hollow inside, and the inner surface of the containing container is fixedly connected to the outer surface of the waterproof cloth 1. There are multiple vertically arranged reinforcing ribs 3, and the multiple reinforcing ribs 3 are arranged in a rectangular interval on the horizontal plane. A vertical reinforcing column 4 is provided between any two adjacent supporting columns 2 arranged along the length direction of the container. The reinforcing column 4 is also fixedly connected to the outer surface of the waterproof cloth 1, and a telescopic component 5 is hinged between each reinforcing column 4 and the adjacent supporting column 2. The telescopic component 5 includes a first connecting rod 501 and a second connecting rod 502 of equal length and hinged to each other. The free end of the first connecting rod 501 is hinged to the adjacent supporting column 2, and a damping is provided at the hinge. The free end of the second connecting rod 502 is hinged to the adjacent reinforcing column 4, and the first connecting rod 501 and the second connecting rod 502 together form a "V" shape. A connecting block 6 vertically fixed to the outer surface of the waterproof cloth 1 is provided between each of the support columns 2 and the reinforcing column 4. The telescopic assembly 5 also includes a limiter 7 coaxially and rotatably connected to the hinge of the first connecting rod 501 and the second connecting rod 502, and one end of the limiter 7 is slidably set on the vertical axis of the connecting block 6 in the vertical direction; any two adjacent support columns 2 arranged along the width direction of the container are connected with a Three steel wire ropes 8, each of which is horizontally arranged, and the three steel wire ropes 8 are spaced apart in a vertical manner, and both ends of each of the steel wire ropes 8 are fixed on the surfaces of two adjacent support columns 2, and when the containing container is extended to its maximum volume, each of the steel wire ropes 8 is in a taut state, and the outer surface of the steel wire ropes 8 is against the outer surface of the waterproof cloth 1, and one side surface of the first connecting rod 501 and the second connecting rod 502 is also against the outer surface of the adjacent waterproof cloth 1, and one side surface of the waterproof cloth 1 is connected to an opening close to the ground, and a nut for closing the opening is connected to the opening.

[0026] As shown in the figure, when it is necessary to stir mortar at the construction site, the four support columns 2 are moved to the farthest positions in all directions. At this time, the first connecting rod 501 and the second connecting rod 502 rotate with each other, and the acute angle between the two gradually increases. Then, each support column 2 is placed vertically on the ground. At this time, a part of the surface of the waterproof cloth 1 is in contact with the ground, and another part of the surface of the waterproof cloth 1 forms a rectangular holding container under the action of each support column 2. At this time, the on-site construction personnel can put the raw materials for mortar mixing into the holding container for stirring. The whole operation process is simple and convenient, and when the mortar mixing is completed and all the mortar is turned out of the holding container, the sealing container can be opened. Close the nut of the opening, and spray clean water into the container for cleaning. The sewage generated during the cleaning process flows out of the container through the opening. After the cleaning is completed, connect the nut with the opening, and gather the four support columns 2 at the same time. At this time, the first connecting rod 501 and the second connecting rod 502 rotate with each other, and the acute angle between the two gradually decreases until the four support columns 2 move to the position closest to each other. At this time, the waterproof cloth 1 shrinks to the smallest state. Since the intersection between the first connecting rod 501 and the second connecting rod 502 is provided with a rotation damping, the waterproof cloth 1 that shrinks to the smallest state can maintain the current state, which is convenient for turnover and greatly reduces the floor space.

[0027] Among them, when the waterproof cloth 1 is unfolded to its maximum volume and is rectangular, the two reinforcing columns 4 arranged in the length direction of the containing container can effectively strengthen and support the surface of the waterproof cloth 1, reducing the deformation area of ​​the waterproof cloth 1 in the length direction of the containing container, and a telescopic component 5 is connected between each reinforcing column 4 and the adjacent support column 2. The first connecting rod 501 and the second connecting rod 502 in the telescopic component 5 not only guide the reinforcing column 4 and the support column 2 during movement, but also limit the reinforcing column 4 and the support column 2 (damping at the hinge of the first connecting rod 501 and the second connecting rod 502), and can also effectively support the outer surface of the waterproof cloth 1, reduce the deformation of the outer surface of the waterproof cloth 1 after being filled with mortar, and further improve the stability of the waterproof cloth 1; and the width direction of the containing container is relatively long because the distance The length of the waterproof cloth 1 is relatively short, and the force on the width direction of the waterproof cloth 1 is not as great as that on the length direction. Therefore, only three steel wire ropes 8 are arranged at intervals in the width direction of the container to abut the outer surface of the waterproof cloth 1, which not only strengthens the stability of the waterproof cloth 1 but also effectively prevents its deformation. When the container is filled with mortar, the mortar will exert pressure on the vertical surfaces of the waterproof cloth 1. The two ends of each steel wire rope 8 are also fixedly connected to two adjacent support columns 2 to strengthen the stability of the container in the width direction. Of course, the stability of the container in the length direction is jointly borne by the telescopic component 5 and the reinforcing column 4, which can effectively support the surrounding areas of the waterproof cloth 1. When the waterproof cloth 1 shrinks to the minimum volume, it is also convenient to adjust the position of each steel wire rope 8, which is convenient for the folding of the waterproof cloth 1 and the later transportation by construction personnel.

[0028] In this embodiment, each of the connecting blocks 6 is of equal length to and corresponds to the adjacent reinforcing ribs 3, and the two are fixedly connected by bolts. Two telescopic components 5 are hinged between each of the supporting columns 2 and the reinforcing columns 4, and the two telescopic components 5 are mirror-imaged with respect to the vertical center of the reinforcing column 4, wherein each of the telescopic components 5 is hinged to the adjacent reinforcing columns 4 and the supporting columns 2, and the limiting members 7 in each of the telescopic components 5 are slidably set in the vertical direction on the vertical axis of the connecting block 6.

[0029] As shown in the combined figure, each connecting block 6 is slidably connected to two telescopic components 5 set in mirror image. When the adjacent reinforcing column 4 and supporting column 2 are close to each other, the two telescopic components 5 connected thereto will be driven to move simultaneously, the first connecting rod 501 and the second connecting rod 502 will rotate with each other, and the acute angle between the first connecting rod 501 and the second connecting rod 502 will gradually decrease. At the same time, the two stoppers 7 on each connecting block 6 will move in a direction away from each other until the reinforcing column 4 and the supporting column 2 move to the closest position and cannot move any further. At this time, each first connecting rod 501 and the second connecting rod 502 will rotate with each other, and the acute angle between the first connecting rod 501 and the second connecting rod 502 will gradually decrease. The damping at the hinge of the rod 501 and the second connecting rod 502 will keep each reinforcing column 4 and support column 2 in the current position, which is convenient for construction workers to transport or carry. When the waterproof cloth 1 is unfolded to its maximum volume, due to the mirror-image arrangement of any two corresponding telescopic components 5, each first connecting rod 501 and second connecting rod 502 will play a certain supporting role on the outer surface of the waterproof cloth 1, thereby enhancing the stability of the waterproof cloth 1 during construction. In addition, the added telescopic components 5 can also effectively improve the stability of the movement between the reinforcing columns 4 and the support columns 2 when the waterproof cloth 1 is unfolded or contracted.

[0030] In this embodiment, in any two of the telescopic components 5 that are mirror-imaged about the vertical center of the reinforcing column 4, the surface of one of the first connecting rods 501 is provided with a strip through hole arranged along its length direction, and the center line of the strip through hole coincides with the center line of the first connecting rod 501, and the surface of the other first connecting rod 501 is hinged with a limit column slidably arranged in the through hole, and among the two adjacent second connecting rods 502, one of the second connecting rods 502 is also provided with a strip through hole, and the surface of the other second connecting rod 502 is hinged with a limit column slidably arranged in the through hole.

[0031] As shown in the combined figure, the two telescopic components 5 between each reinforcement column 4 and the support column 2 are arranged crosswise with each other (relative to the two first connecting rods 501 and the two second connecting rods 502 are not in the same vertical plane), and the two first connecting rods 501 and the two second connecting rods 502 arranged in a mirrored manner are connected together by means of the strip through holes and the limiting columns, which can effectively improve the stability of the movement between the two telescopic components 5 and the connection strength between the two, thereby indirectly improving the supporting effect on the outer surface of the container.

[0032] In this embodiment, two slide grooves 9 are provided on the surface of each of the connecting blocks 6, and the two slide grooves 9 are symmetrically arranged about the axis in the width direction of the connecting block 6, and the center line of each slide groove 9 in the length direction coincides with the center line of the length direction of the connecting block 6. The limiting member 7 includes a limiting rod 14 and a slider 10 threadedly connected to one end of the limiting rod 14, and the slider 10 is slidably arranged in each slide groove 9, and the limiting rod 14 is coaxially and rotatably connected to the hinge of the first connecting rod 501 and the second connecting rod 502.

[0033] As shown in the figure, by rotating one end of the limit rod 14, the slider 10 and the end of the limit rod 14 with a thread can be made to abut the inner wall of the slide groove 9, thereby fixing the hinge of the first connecting rod 501 and the second connecting rod 502 at the current position, so that the first connecting rod 501 and the second connecting rod 502 cannot continue to rotate, which can further improve the stability of the waterproof cloth 1; continue to rotate one end of the limit rod 14 so that the slider 10 no longer abuts the inner wall of the slide groove 9. At this time, the first connecting rod 501 and the second connecting rod 502 can continue to rotate with each other, and the waterproof cloth 1 can be unfolded or tightened. While the operation is simple and convenient, it can also improve the stability between the telescopic component 5 and the connecting block 6.

[0034] In this embodiment, the inner surface of the waterproof cloth 1 is connected with a plurality of connecting strips 11 corresponding to the support columns 2 and the reinforcing columns 4 respectively. The length of the connecting strip 11 is slightly smaller than the length of the support column 2 (the length of the support column 2 and the reinforcing column 4 is equal to the height of the container). Each of the connecting strips 11 is vertically arranged and fixedly connected to the adjacent support column 2 and reinforcing column 4 by bolts.

[0035] As shown in the figure, the setting of the connecting block 6 not only increases the contact area between the waterproof cloth 1 and each supporting column 2 and reinforcing column 4, but also strengthens the connection stability between the waterproof cloth 1 and each supporting column 2 and reinforcing column 4, thereby indirectly improving the support and stabilization effect of the supporting column 2 and reinforcing column 4 on the waterproof cloth 1.

[0036] In this embodiment, the outer surface of each of the steel wire ropes 8 is sleeved with a plurality of fixed sleeve strips 12 arranged at intervals, and each fixed sleeve strip 12 is sewn and fixedly connected to the outer surface of the waterproof cloth 1 .

[0037] As shown in the figure, the setting of the fixed sleeve 12 can not only limit the steel wire rope 8 to prevent the steel wire rope 8 from making irregular movements when the waterproof cloth 1 shrinks, but also increase the connection stability between the steel wire rope 8 and the outer surface of the waterproof cloth 1.

[0038] In this embodiment, the bottom end of each of the supporting columns 2 and reinforcing columns 4 is detachably connected to a base 13 .

[0039] The setting of the base 13 can effectively improve the stability of each support column 2 and reinforcement column 4 when placed on the ground, providing an effective support premise for supporting the container, and the detachable base 13 is also convenient to remove and place in the waterproof cloth 1, reducing the footprint of the waterproof cloth 1 after shrinkage.

[0040] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A novel retractable mortar box, comprising a waterproof cloth (1) for containing mortar and support columns (2) arranged around the waterproof cloth (1), characterized in that: The support columns (2) are provided with four pieces and are arranged in a rectangular shape in a horizontal plane, wherein each of the support columns (2) is arranged vertically, and the four support columns (2) are fixedly supported on the outer surface of the waterproof cloth (1) to form a rectangular container, and the inner surface of the container is fixedly connected with a plurality of vertical reinforcing ribs (3), and the plurality of reinforcing ribs (3) are arranged at intervals in a rectangular shape, and a vertical reinforcing column (4) is provided between two support columns (2) arranged along the length direction of the container, and a telescopic component (5) is hingedly connected between each reinforcing column (4) and an adjacent support column (2), and the telescopic component (5) comprises a first connecting rod (501) and a second connecting rod (502) of equal length and hinged to each other, the free end of the first connecting rod (501) being hinged to the adjacent support column (2), and the free end of the second connecting rod (502) being hinged to the adjacent support column (2). The adjacent reinforcing columns (4) are hinged to each other, and the first connecting rod (501) and the second connecting rod (502) together form a "V" shape. A connecting block (6) vertically fixed to the outer surface of the waterproof cloth (1) is provided between each of the support columns (2) and the reinforcing columns (4). The telescopic assembly (5) also includes a limiter (7) coaxially and rotatably connected to the hinge of the first connecting rod (501) and the second connecting rod (502), and the limiter (7) is slidably arranged on the vertical axis of the connecting block (6) in the vertical direction. A plurality of steel wire ropes (8) are connected between the two support columns (2) arranged along the width direction of the container, and both ends of each steel wire rope (8) are fixed to the surfaces of two adjacent support columns (2), and when the container is extended to its maximum volume, the surface of each steel wire rope (8) is against the outer surface of the waterproof cloth (1).

2. A novel retractable mortar box according to claim 1, characterized in that: Each of the connecting blocks (6) corresponds to and is fixedly connected to the adjacent reinforcing ribs (3); two telescopic components (5) are hinged between each of the supporting columns (2) and the reinforcing columns (4); and the two telescopic components (5) are arranged in a mirror image with respect to the vertical center of the reinforcing column (4); each of the telescopic components (5) is hinged to the adjacent reinforcing column (4) and the supporting column (2); and the limiting components (7) in each of the telescopic components (5) are arranged to slide in the vertical direction on the vertical axis of the connecting block (6).

3. A novel retractable mortar box according to claim 2, characterized in that: In any two of the telescopic assemblies (5) arranged in a mirror image, two adjacent first connecting rods (501) are hinged to each other and can be slidably connected along their length direction, and two adjacent second connecting rods (502) are hinged to each other and can be slidably connected along their length direction.

4. A novel retractable mortar box according to claim 3, characterized in that: Two slide grooves (9) are provided on the surface of each connecting block (6), and the two slide grooves (9) are symmetrically arranged about the axis of the width direction of the connecting block (6), and the center line of each slide groove (9) in the length direction coincides with the center line of the length direction of the connecting block (6). The limiting member (7) includes a limiting rod (14) and a slider (10) threadedly connected to one end of the limiting rod (14), and the slider (10) is slidably arranged in each slide groove (9), and the limiting rod (14) is coaxially and rotatably connected to the hinge of the first connecting rod (501) and the second connecting rod (502).

5. A novel retractable mortar box according to claim 4, characterized in that: The inner surface of the waterproof cloth (1) is connected to a plurality of connection strips (11) corresponding to the support columns (2) and the reinforcement columns (4) respectively, and each of the connection strips (11) is vertically arranged and fixedly connected to the adjacent support column (2) and reinforcement column (4) by bolts.

6. A novel retractable mortar box according to claim 5, characterized in that: The outer surface of each steel wire rope (8) is sleeved with a plurality of fixed sleeve strips (12) arranged at intervals, and each fixed sleeve strip (12) is fixedly connected to the outer surface of the waterproof cloth (1).

7. A novel retractable mortar box according to claim 6, characterized in that: The bottom end of each of the support columns (2) and reinforcement columns (4) is detachably connected to a base (13).

Images