Patent Publication Number: US-2023151619-A1

Title: Pointing tool

Description:
RELATED APPLICATION 
     This application is a continuation-in-part (CIP) application claiming benefit of PCT/CN2020/103290 filed on Jul. 21, 2020, the disclosure of which is incorporated herein in its entirety by reference. 
    
    
     The present invention relates to the field of building construction and, in particular to a pointing tool. 
     DESCRIPTION OF THE PRIOR ART 
     In the field of construction, bricklaying is one of the common construction activities. During bricklaying, gaps are left between adjacent bricks. One reason for this is that perfect fitting of bricks is impossible because they could not be perfectly made or because abrasion is inevitable. Another reason is that it is sensible to reserve spaces between bricks in order to accommodate their thermal expansion. Otherwise, bricks may be squeezed by each other at raised temperatures, which may lead to cracking or deformation. Pointing refers to filling of such gaps with a filling material, which may be either directly the cement or binder used to stabilize the bricks, or a filling material specially designed for pointing. Before the filling material becomes dry and invariable in shape, a pointing tool can be used to surface finish the filling material for practical or aesthetic purposes. In addition, pointing may also be applied between the floor and walls for the purposes of waterproofing, aesthetics and gap filling. 
     Different applications have different pointing requirements. For example, in applications with demanding waterproofing and drainage requirements, cross-sectional “V-shaped” or similar recessed gaps are needed because such “V-shaped” gaps allow not only rapid drainage of water but also denser filling of filling materials, which is favorable for waterproofing performance. In other instances, possibly for aesthetic or other reasons, it is necessary to form gaps of various cross-sectional shapes. Even gaps of the same cross- sectional shape will have different surface shapes due to various sizes. Therefore, working members of pointing tools are required to have various surfaces that can meet different application requirements. 
     In the prior art, most pointing tools are integral structures having surfaces of fixed shapes, and therefore, can only fill gaps of respective determined cross-sectional shapes. For this reason, a construction worker has to carry a set of pointing tools with her/him in order to be able to fill various gaps. This is costly and introduces inconvenience. Although there are some pointing tools in the prior art having two different surfaces, due to the structurally integral nature, their working members do not allow angular adjustment. As a consequence, the use of the different surfaces may cause inconvenient gripping and inferior construction results. 
     Therefore, those skilled in the art are directing their effort toward developing a pointing tool, which has a working member with multiple surfaces of different shapes while offering convenient gripping, allows easy surface shape adjustments as required, and can prevent a filling material from entering the inside of the pointing tool. 
     SUMMARY OF THE INVENTION 
     In view of the above described shortcomings of the prior art, the problem sought to be solved by the present invention lies in how to provide an adjustable pointing tool including multiple different curved surfaces and capable of presenting the entry of particulate matter. 
     In order to solve the above problem, the present invention provides a pointing tool comprising a working member and a gripping member, the working member coupled to the gripping member, wherein the working member is configured to be able to rotate to adjust a working surface, the working surface comprising a plurality of curved surfaces. 
     Additionally, a first connecting part extends from one end of the gripping member, and the working member comprises a first working member. The first working member is rotatably disposed over the first connecting part, and a stop mechanism is further included. The stop mechanism is configured to maintain the first working member at a constant position with respect to the first connecting part. 
     Additionally, the stop mechanism comprises a polygonal prismatic stop recess provided at an inner surface of the first working member and a polygonal prismatic stop body provided in a terminal portion of the first connecting part. The polygonal prismatic stop body matches the polygonal prismatic stop recess in size and shape. The polygonal prismatic stop recess has degrees of surface curvature matching degrees of curvature of an outer surface of the first working member at corresponding positions. When the first working member is laterally moving over the first connecting part, the polygonal prismatic stop body is able to engage with or leave from the polygonal prismatic stop recess. The polygonal prismatic stop body engages with the polygonal prismatic stop recess to maintain the first working member at a constant position with respect to the first connecting part, and the polygonal prismatic stop body disengages from the polygonal prismatic stop recess to enable the first working member to be rotatable about the first connecting part. 
     Additionally, the stop mechanism further comprises a locking pin fixedly coupled to the polygonal prismatic stop body. The locking pin is inserted and pulled out to enable the polygonal prismatic stop body to engage with and disengage from the polygonal prismatic stop recess. 
     Additionally, the stop mechanism further comprises a spring disposed within the first working member. The spring is disposed over the first connecting part together with the polygonal prismatic stop body. One end of the spring is coupled to the terminal portion of the first working member, and another end thereof to a base portion of the first connecting part. The spring is compressed when the polygonal prismatic stop body disengages from the polygonal prismatic stop recess and returns to a rest state in absence of an external force to enable the polygonal prismatic stop body to engage with the polygonal prismatic stop recess. 
     Additionally, an inner surface of the terminal portion of the first working member is provided with a collar, and one end of the spring is coupled to the collar. The base portion of the first connecting part is provided therein with a trailing cover receptacle, and a trailing cover is snapped into the trailing cover receptacle and thereby fixedly coupled to the first connecting part. The spring is fixedly coupled to the trailing cover at the other end. 
     Additionally, the polygonal prismatic stop body and the trailing cover are integrally formed over the first connecting part. 
     Additionally, the outer surface of the first working member is triangular prismatic, or quadrangular prismatic, or pentagonal prismatic, or hexagonal prismatic. 
     Additionally, a sealing member is further included, which is disposed in the terminal portion of the first working member. 
     Additionally, the first working member is coupled to the gripping member at a base portion of the first connecting part. Either of the first working member and the gripping member is provided therein with a plurality of elongate stop recesses, and the other of them is provided thereon with elongate stop body matching the elongate stop recesses in size. When the first working member is laterally moving over the first connecting part, the elongate stop body is able to engage with or leave from the elongate stop recesses. The elongate stop body engages with the elongate stop recesses to maintain the first working member at a constant position with respect to the first connecting part, and the elongate stop body disengages from the elongate stop recesses to enable the first working member to be rotatable about the first connecting part. 
     Additionally, the number of the elongate stop recesses is the same as the number of the elongate stop body. 
     Additionally, the stop mechanism further comprises a trailing plug provided in a terminal portion of the first connecting part. The trailing plug is configured to limit a lateral position of the first working member and, through altering a lateral position of the trailing plug, control engagement and disengagement of the elongate stop body with and from the elongate stop recesses. 
     Additionally, the trailing plug comprises an elongate rotary handle configured to be raised over an end face of the first working member and used to change the lateral position of the trailing plug. 
     Additionally, the trailing plug comprises an elongate groove used to change the lateral position of the trailing plug. 
     Additionally, the stop mechanism comprises a metal wire, one end of which is coupled to the first connecting part. The first working member is provided in a terminal portion thereof with a stop groove matching the metal wire in size. Engagement of another end of the metal wire with the stop groove results in the first working member being stopped, and disengagement of another end of the metal wire from the stop groove results in adjustability of the first working member. 
     Additionally, the first connecting part is provided in a surface thereof with metal wire securing holes, and the metal wire is inserted into the metal wire securing holes to be pivotably coupled to the first connecting part. 
     Additionally, the first connecting part comprises a threaded rod, and the first working member is fixedly coupled to the threaded rod. The threaded rod is rotatably coupled to the gripping member, and a side face of a base portion of the first working member is engaged with a side face of the gripping member. One of the side face of the base portion of the first working member and the side face of the gripping member is provided thereon with raised beads, and the other of them is provided therein with bead receiving pockets. The raised beads and the bead receiving pockets are arranged around the threaded rod. The raised beads are in positional correspondence with the bead receiving pockets. When the first connecting part is being rotated with the threaded rod relative to the gripping member, the raised beads are able to engage with or leave from the bead receiving pockets. The raised beads engage with the bead receiving pockets to maintain the first working member at a constant position with respect to the first connecting part, and the raised beads disengages from the bead receiving pockets to enable the first working member to be rotatable about the first connecting part. 
     Additionally, a second connecting part extends from an end of the gripping member opposite to the first connecting part, and the working member comprises a second working member disposed over the second connecting part. 
     Additionally, the first working member differs from the second working member in outer surface shape and size, and the first connecting part has the same structure as that of the second connecting part. 
     Additionally, the outer surface of the first working member is triangular prismatic, or quadrangular prismatic, or pentagonal prismatic, or hexagonal prismatic. 
     Compared with the prior art, the present invention has at least the following benefits: 
     1. The present invention can provide multiple pointing surfaces of different shapes and can thus integrate the functions of multiple prior art products of different specifications. Therefore, it is more economic and less costly. 
     2. The coupling of the gripping member and the working member according to the present invention enables more convenient adjustment of the working member, which can result in an increase in operating efficiency. 
     3. The present invention has superior sealing performance, which can protect the pointing tool against the influence of any filling material, thereby extending the service life and reducing the cost. 
     Below, the concept, structural details and resulting technical effects of the present invention will be further described with reference to the accompanying drawings to provide a full understanding of the objects, features and effects of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic overview of one embodiment of the present invention; 
         FIG.  2    schematically illustrates working surfaces in one embodiment of the present invention; 
         FIG.  3    schematically illustrates a working surface in one embodiment of the present invention; 
         FIG.  4    is a side view of one embodiment of the present invention; 
         FIG.  5    is a cross-sectional view of one embodiment of the present invention; 
         FIG.  6    is an exploded schematic view of one embodiment of the present invention; 
         FIG.  7    is a schematic overview of another embodiment of the present invention; 
         FIG.  8    is a side view of another embodiment of the present invention; 
         FIG.  9    is an exploded schematic view of another embodiment of the present invention; 
         FIG.  10    is a schematic overview of a further embodiment of the present invention; 
         FIG.  11    is an exploded schematic view of a further embodiment of the present invention; 
         FIG.  12    is a cross-sectional view of another embodiment of the present invention; 
         FIG.  13    shows a switch between different configurations as a result of an adjustment action in another embodiment of the present invention; 
         FIG.  14    is a schematic overview of a further embodiment of the present invention; 
         FIG.  15    is an exploded schematic view of a further embodiment of the present invention; 
         FIG.  16    is a cross-sectional view of a variant of one embodiment of the present invention; 
         FIG.  17    is a schematic overview of a further embodiment of the present invention; 
         FIG.  18    is a side view of a further embodiment of the present invention; 
         FIG.  19    is a cross-sectional view of a working member in a further embodiment of the present invention; and 
         FIG.  20    is a cross-sectional view of a working member in a further embodiment of the present invention, 
     
    
    
     wherein  101  denotes a gripping member;  1011 , a first connecting part;  1011 ′, a second connecting part;  1012 , a first sealing ring;  1012 ′, a second sealing ring;  1013 , a first stop block;  1013 ′, a second stop block;  102 , a first working member;  1021 , a first stop notch;  103 , a second working member;  1031 , a second stop notch;  104 , a connecting rod;  105 , a first trailing plug;  105 ′, a second trailing plug;  1051 , a third sealing ring;  1051 ′, a fourth sealing ring;  1052 , a first elongate rotary handle;  1053 , a first elongate groove;  201 , a gripping member;  202 , a first working member;  2021 , a first stop groove;  203 , a second stop groove;  204 , a connecting rod;  207 , a metal wire;  2071 , fixed metal wire sections;  2072 , a movable metal wire section;  301 , a first working member;  302 , a first connecting part;  303 , a gripping member;  305 , a triangular prismatic stop recess;  306 , a circular collar;  307 , a triangular prismatic stop body;  308 , a spring;  309 , a trailing cover;  310 , a connecting rod;  311 , a screw;  401 , a first working member;  402 , a first connecting part;  403 , a gripping member;  405 , a triangular prismatic stop recess;  406 , a circular collar;  407 , a triangular prismatic stop body;  408 , a spring;  409 , a trailing cover;  410 , a connecting rod;  411 , a screw;  501 , a first working member;  502 , a first connecting part;  503 , a gripping member;  505 , a hexagonal prismatic stop recess;  511 , a locking pin;  601 , a first working member;  607 , a pentagonal prismatic stop body;  701 , a first working member;  702 , a gripping member;  703 , a threaded rod;  704 , raised beads; and  705 , bead receiving pockets. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Below, the drawings accompanying this specification are referenced to introduce many preferred embodiments of the present invention so that the techniques disclosed herein become more apparent and better understood. The present invention may be embodied in many different forms of embodiment, and its protection scope is not limited only to the embodiments mentioned herein. 
     Throughout the accompanying drawings, structurally identical parts are indicated with identical reference numerals, and structurally or functionally similar components are indicated with similar reference numerals. The size and thickness of each element in the drawings are arbitrarily depicted, and the present invention is not limited to any size or thickness of each element. For greater clarity of illustration, the thicknesses of some parts are exaggerated as appropriate somewhere in the drawings. According to the present application, all connecting members and working members are elongate, and the working members are disposed over the respective connecting members so as to be rotatable thereabout. In some embodiments, the connecting members are each an elongate connecting rod. A portion at an end proximal to a gripping member is referred to as a “base portion”, as in the terms “base portion of the connecting member”, “base portion of the working member”, “base portion of the connecting rod” and the like that may be used herein. Moreover, a portion at an end distal from a gripping member is referred to as a “terminal portion”, as in the terms “terminal portion of the connecting member”, “terminal portion of the working member”, “terminal portion of the connecting rod” and the like that may be used herein. For an elongate component, a direction along a length of this component is referred to as a “lateral direction”, as in the terms “lateral position”, “lateral movement” and the like that may be used herein. 
     Embodiment 1: 
     As shown in  FIGS.  1  to  6   , this embodiment includes a gripping member  101 . A first connecting part  1011  extends from one end of the gripping member  101 , and a first sealing ring  1012  is disposed over the first connecting part  1011 . A second connecting part  1011 ′ extends from the other end of the gripping member  101 , and a second sealing ring  1012 ′ is disposed over the second connecting part  1011 ′. A first working member  102  and a second working member  103  are disposed over the first connecting part  1011  and the second connecting part  1011 ′, respectively. The first working member  102  and the second working member  103  have different sizes and outer surface shapes, but both the first working member  102  and the second working member  103  are generally cylindrical. As part of a connecting member, the connecting rod  104  extends through the first connecting part  1011 , the gripping member  101  and the second connecting part  1011 ′, and both the first working member  102  and the second working member  103  are disposed over the connecting rod  104  so as to be rotatable about the connecting rod  104 . Each of the first working member  102  and the second working member  103  has two cylindrical curved surfaces of different radii of curvature, which serve as working surfaces of the present invention. As used herein, the “radii of curvature” refer to those of curved lines of cross- sections of the working members in planes perpendicular to an axis of the connecting rod  104 , which correspond to the working surfaces. As shown in  FIG.  2   , in other similar embodiments, each working member may have three working surfaces connected by transition surface portions. The transition surface portions may be circular cylindrical surfaces with greater radii of curvature than those of the working surfaces (i.e., convex surfaces, as shown in  FIG.  2   a   ), planes (as shown in  FIG.  2   b   ), or circular cylindrical surfaces with negative radii of curvature (i.e., concave surfaces, as shown in  FIG.  2   c   ). Regardless of how the transition surface portions are configured, in order to ensure satisfactory use of the working surfaces at wall corners, in the cross section of the working member, an angle formed between tangents at endpoints of the corresponding curved line of each working surface is desired to be an acute angle less than 90 degrees, such as the angle a shown in  FIG.  3   . 
     As a stop mechanism in this embodiment, the connecting members are provided thereon with elongate stop bodies, and the working members are provided with elongate stop recesses complementary in shape thereto. Specifically, as shown in  FIG.  6   , a first stop block  1013  may be provided on the first connecting part  1011 , and a second stop block  1013 ′ may be provided on the second connecting part  1011 ′. Correspondingly, two first stop notches  1021  may be provided in the two different circular cylindrical surfaces of the first working member  102 , and two second stop notches  1031  may be provided in the two different circular cylindrical surfaces of the second working member  103 . When the first stop block  1013  moves into engagement with any of the two first stop notches  1021  as a result of lateral displacement of the first working member  102  over the connecting rod  104 , the first working member  102  is stopped in position. If the first stop block  1013  fails to engage with any of the first stop notches  1021 , i.e., the first stop block  1013  remains separate from the first stop notches  1021 , the first working member  102  is not stopped and angular adjustment thereof is allowed. Correspondingly, when the second stop block  1013 ′ moves into engagement with any of the two second stop notches  1031  as a result of lateral displacement of the second working member  103  over the connecting rod  104 , the second working member  103  is stopped in position. If the second stop block  1013 ′ fails to engage with any of the second stop notches  1031 , i.e., the second stop block  1013 ′ remains separate from the second stop notches  1031 , the second working member  103  is not stopped and angular adjustment thereof is allowed. A first trailing plug  105  and a second trailing plug  105 ′ are threadedly coupled to opposing ends of the connecting rod  104 . The first trailing plug  105  is disposed at a terminal end of the first working member  102 , and the second trailing plug  105 ′ is disposed at a terminal end of the second working member  103 . The first trailing plug  105  and the second trailing plug  105 ′ are used to limit lateral displacement of the first working member  102  and the second working member  103  on the connecting rod  104 . The first trailing plug  105  and the second trailing plug  105 ′ are provided thereon with a third sealing ring  1051  and a fourth sealing ring  1051 ′, respectively. The first trailing plug  105  is provided thereon with a first elongate rotary handle  1052 , which can facilitate rotation of the first trailing plug  105  by an operator&#39;s hand. The first elongate rotary handle  1052  is raised over a terminal end face of the first working member  102 . The first elongate rotary handle  1052  is provided in a surface thereof a first elongate groove  1053 , in which the insertion of a simple tool (e.g., a screwdriver) for rotating the first trailing plug  105  can be accommodated. Correspondingly, the second trailing plug  105 ′ is provided thereon with a second elongate rotary handle and a second elongate groove (not shown) for a similar purpose. 
     In order to make an adjustment to the first working member  102 , the first trailing plug  105  is screwed via the first elongate rotary handle  1052  a predetermined distance out of the first working member  102  to allow the first working member  102  to displace laterally to separate the first stop block  1013  from the first stop notch  1021 . As a result, the first working member  102  is in an adjustable configuration. After the first working member  102  is rotated to a deployment position of a desired circular cylindrical surface, the first stop block  1013  is aligned with one of the first stop notches  1021 , and the first trailing plug  105  is tightened to cause the first working member  102  to laterally move to again engage the first stop block  1013  with the first stop notch  1021 , thereby locking the first working member  102 . The second working member  103  can be adjusted by manipulating the second trailing plug  105 ′ in a similar manner involving disengagement of the second stop block  1013 ′ from the second stop notch  1031  and reengagement of the second stop block  1013 ′ with one of the second stop notches  1031 , and similar results can be obtained. 
     It is to be noted that, although the first working member  102  and the second working member  103  have been described in this embodiment as being sized distinctly and having outer surfaces with different radii of curvature, in alternative embodiments, the first working member  102  and the second working member  103  may be identically sized or have components with identical outer surfaces. In this embodiment, one first stop block  1013  and one second stop block  1013 ′ are provided, but in alternative embodiments, the same number of first stop blocks  1013  and first stop notches  1021  and the same number of second stop block  1013 ′ and second stop notches  1031  may be provided. In further embodiments, the stop notch(es) may be provided in the connecting members and the stop block(s) on the working members. That is, they are swapped in position, as compared to this embodiment. Similar effects can be obtained. 
     Embodiment 2: 
     As shown in  FIGS.  7  to  9   , this embodiment includes a gripping member  201 , a first working member  202 , a second working member  203  and a connecting rod  204 , which are the same as the gripping member  101 , the first working member  102 , the second working member  103  and the connecting rod  104  in Embodiment 1. This embodiment differs from embodiment 1 in having a different stop mechanism. In this embodiment, the first working member  202  and the second working member  203  are stoppable by two metal wires  207 . Each metal wire  207  includes fixed metal wire sections  2071  and a movable metal wire section  2072 . The fixed metal wire sections  2071  are rotatably coupled to the first connecting part. In this embodiment, specifically, metal wire securing holes are provided on opposing side faces of the first connecting part, and the fixed metal wire sections  2017  are inserted into the metal wire securing holes to pivotably couple the metal wire  207  to the first connecting part. The movable metal wire section  2072  is annular and defines an opening. The first working member  202  and the second working member  203  are provided at their terminal ends with a first stop groove  2021  and a second stop groove (not shown), with which the movable metal wire sections  2072  can engage in a self- locating manner. Upon the movable metal wire section  2072  coming into engagement with the first stop groove  2021 , the first working member  202  will be stopped in position. When the movable metal wire section  2072  is separated from the first stop groove  2021 , adjustment of the first working member  202  is possible. The second working member  203  can be stopped and enabled to allow adjustment by manipulation the metal wire  2072  with respect to the second stop groove in a similar manner. 
     Embodiment 3: 
     As shown in  FIGS.  10  to  13   , this embodiment includes a first working member  301 , a first connecting part  302  and a gripping member  303  fixedly attached to the first connecting part  302 . The first working member  301  is a hollow triangular prism having an outer surface including three cylindrical curved surfaces with different radii of curvature and an inner surface defining a hollow circular cylindrical cavity. The first working member  301  is disposed over the first connecting part  302  so that the first connecting part  302  is received within its hollow cavity and that it can rotate about the first connecting part  302 . The hollow cavity is provided at a terminal end thereof with a triangular prismatic stop recess  305 , and an inward circular collar  306  is provided at the junction of the hollow cavity and the triangular prismatic stop recess  305 . The first connecting part  302  includes a substantially circular cylindrical connecting rod  310 , and the connecting rod  310  is detachably provided at a terminal end thereof corresponding to the stop recess  305  with a triangular prismatic stop body  307  matching the stop recess  305  in terms of both shape and dimensions. The connecting rod  310  is also disposed thereover with a spring  308 , one end of which is stopped at the circular collar  306  in the hollow cavity. A trailing plug  309  is detachably provided at a trailing end of the hollow cavity, and the other end of the spring  308  is stopped at the trailing plug  309  so that the spring  308  is confined within the hollow cavity of the first working member  301 . The first working member  301  is detachably coupled to the connecting rod  310  by a screw  311 . 
     In order to make an adjustment to the first working member  301 , as shown in  FIG.  13   , a lateral external force is applied to the first working member  301  to cause it to move toward a trailing end of the connecting rod  310 . As a result, the end of the spring  308  stopped by the trailing cover  309  does not displace, while the other end of the spring  308  is driven by the circular collar  306  to move toward the trailing end of the connecting rod  310 , resulting in compression of the spring  308 . As another result of the lateral displacement of the first working member  301 , the triangular prismatic stop recess  305  is separated from the triangular prismatic stop body  307 , allowing the first working member  301  to be rotated and adjusted, i.e., switched from configuration a to b as shown in  FIG.  13   . When a desired circular cylindrical surface is adjusted to the deployment position, the lateral external force applied to the first working member  301  is withdrawn to release the first working member  301 . Under the action of the spring  308 , the triangular prismatic stop body  307  is pulled back into the triangular prismatic stop recess  305  of the first working member  301 , again stopping the first working member  301 . As a result of this process, a switch from configuration b to c as shown in  FIG.  13    is accomplished. 
     Embodiment 4: 
     As shown in  FIGS.  14  to  16   , this embodiment includes a first working member  401 , a first connecting part  402 , a gripping member  403 , a triangular prismatic stop recess  405 , a circular collar  406 , a triangular prismatic stop body  407 , a spring  408 , a trailing cover  409 , a connecting rod  410  and a screw  411 , which are the same as those of Embodiment 3. 
     This embodiment differs from Embodiment 3 in that the triangular prismatic stop body  407  is fixed to the connecting rod  410 , preferably integrally formed therewith. Moreover, the trailing cover  409  is fixed to the connecting rod  410 , preferably integrally formed therewith. This can simplify the structure of the components and avoid separate fabrication of the three different components followed by assembly of them together, thereby reducing the cost and improving the device&#39;s stability. 
     Embodiment 5: 
     As shown in  FIGS.  17  to  18   , this embodiment comprises a first working member  501  having a hexagonal prismatic outer surface including six circular cylindrical surfaces with different radii of curvature. The first working member  501  is disposed over a first connecting part  502 . The first connecting part  502 , as well as a gripping member  503 , is the same as that of Embodiment 3. 
     In a stop mechanism of this embodiment, an inner surface of the first working member  501  defines a hexagonal prismatic stop recess  505  in shape correspondence with the hexagonal prismatic outer surface, and a hexagonal prismatic stop body complementary in shape thereto is provided. Different from the previous embodiment, the hexagonal prismatic stop body in this embodiment further includes a locking pin  511 . In order to make an adjustment to the first working member  501 , the locking pin  511  is pulled toward a terminal end of the first connecting part  502  to cause the hexagonal prismatic stop body to separate from the hexagonal prismatic stop recess  505  to allow the first working member  501  to be rotated and adjusted. When a suitable circular cylindrical surface is adjusted to the deployed position, the locking pin  511  is inserted in a direction toward a trailing end of the first connecting part  502  to engage the hexagonal prismatic stop body with the hexagonal prismatic stop recess  505 , thereby locking the first working member  501 . 
     Embodiment 6: 
     As shown in  FIG.  19   , a working member in this embodiment is a first working member  601  defining a pentagonal prismatic stop recess, and a corresponding pentagonal prismatic stop body  607  is provided correspondingly. It is to be noted that the shapes of the working member, the stop recess and the stop body of this embodiment are applicable to other embodiments of the present application. Alternatively, the shape of the working member, the stop recess and the stop body in other embodiments may be configured as a triangular, quadrangular, pentagonal, hexagonal and higher-order polygonal shape. 
     Embodiment 7: 
     As shown in  FIG.  20   , a first working member  701  and a gripping member  702  are coupled by a threaded rod  703  in this embodiment. The first working member  701  can rotate about the threaded rod  703 , and a side face of a base portion of the first working member  701  is engaged with a gripping member  702 . The first working member  701  is provided on the side face of the base portion with a plurality of raised beads  704 , and bead receiving pockets  705  is provided in a side face of the gripping member  702  with which the side face of the base portion of the first working member  701  is engaged. The raised beads  704  and bead receiving pockets  705  are in positional correspondence. In order to make an adjustment to the first working member  701 , the threaded rod  703  is rotated to drive the first working member to rotate about the threaded rod  703  to cause the raised beads  704  to leave the bead receiving pockets  705 . Upon the raised beads  704  being again received in the bead receiving pockets  705  at another position, the first working member  701  is stopped. 
     Preferred specific embodiments have been described in detail above. It is to be understood that, those of ordinary skill in the art can make various modifications and changes based on the concept of the present invention without exerting any creative effort. Accordingly, all the technical solutions that can be obtained by those skilled in the art by logical analysis, inference or limited experimentation in accordance with the concept of the present invention on the basis of the prior art are intended to fall within the protection scope as defined by the claims.