Patent Publication Number: US-2012042495-A1

Title: Shoring post with quick release feature

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to shoring posts and, more particularly, to a shoring post that can be reconfigured to instantaneously reduce compressive loading thereupon. 
     2. Background Art 
     Shoring posts are used in many industries and commonly in the construction field as formwork components. A typical shoring post has telescoping parts that can be releasably maintained in a desired relationship using a pin. In one exemplary construction, an upper post part slides within a lower post part and has through openings at regularly spaced vertical intervals. By directing a pin through one of the openings, diametrically opposite portions of the pin will bear upon the lower post part to maintain the overall nominally desired length of the post. One or more threaded components allow additional controlled length extension, thereby to effectively load the shoring post in compression between facing surfaces, commonly on a subjacent floor and an overhead beam. The threaded component may be in the form of a jack on the upper post part that is turned in opposite directions to selectively move an associated bearing plate upwardly and downwardly. In an alternative form, an extension sleeve is threadably engaged with the bottom post part and is borne upon by the aforementioned pin extending through the selected opening in the upper post part. Turning of the extension sleeve causes the sleeve to move upwardly or downwardly, depending upon the direction of turning, with the former causing the effective length of the shoring post to increase. 
     Once the shoring post is installed, it is typically under considerable compression. In the event that a shoring post is required to be reset or removed during, or at the conclusion of, a project, the compressive force must be released before the shoring post can be separated or disassembled. One option for releasing the compressive force is to reverse the last steps that placed the shoring post in compression. That is, the threaded jack component or extension sleeve might be turned reversely to thereby reduce the effective overall length of the shoring post. 
     Alternatively, and in the interest of saving time and minimizing user fatigue, it is known to incorporate a quick release feature whereby a simple step will instantaneously release compressive loading upon the shoring post to allow its resituation or removal. 
     One exemplary form of quick release mechanism is shown in U.S. Pat. No. 5,310,153 (Jackson). In Jackson, a contoured washer is interposed between the pin in an upper post part and an extension sleeve. By turning the washer relative to the pin in one direction around the vertical axis, the effective length of the shoring post can be progressively increased, whereas turning in the opposite direction shortens the effective length of the shoring post. The pin resides in a pair of diametrically opposite “cradling seats” with the washer in one angular, operative orientation. 
     While Jackson permits instantaneous reduction of compressive loading upon a shoring post, at least one limitation with this structure is apparent when used in a typical construction environment. On construction sites whereat formwork is in place, it is common for the shoring posts to be abruptly loaded, as when heavy materials are placed or dropped on overlying surfaces supported by the bearing posts. The bearing posts may also be subjected to vibration due to loading or other activities performed at a site. These dynamic forces may instantaneously or progressively cause shoring post components to shift/turn relative to each other. In Jackson, it is conceivable that the components under such forces might relatively move to the point that the pin will move angularly out of the cradling seats, thereby causing the upper post to shift downwardly and reduce the compressive loading. 
     In the event that the quick release feature permits only a modicum of movement of the upper post part relative to the lower post part, this inadvertent release action might not cause the shoring post to shift to the point that it fails to support the overhead structure that it engages. In any event, the shoring post in the changed state might have to be readjusted to generate the requisite compressive force and/or appropriately position the overlying vertical component that it engages. 
     In a worst case, the inadvertent reduction in the compressive forces upon the shoring post may result in a significant shifting of the shoring post and/or the structure it supports. This not only represents an inconvenience, but could result in a significant structural failure and, potentially, personal injury to those working at the site. 
     While the importance of incorporating a quick release feature into a shoring post has been appreciated for decades, the industry has not devised a structure that can be simply operated and will maintain a fixed shoring post length, regardless of the forces that the shoring post may be subjected to. In an industry where safety and efficiency are critical, and often competing objectives, the need for improved shoring post structures remains. 
     SUMMARY OF THE INVENTION 
     In one form, the invention is directed to a shoring post having: first and second post parts that are slidable guidingly relative to each other along a lengthwise line to cooperatively define a variable effective length; a quick release assembly; and a movable pin that is extended into the first post part to an operative position wherein the pin abuts to the quick release assembly to limit movement of the first post part in one lengthwise direction relative to the second post part. The quick release assembly has: a) at least a first surface against which the pin bears with the pin and quick release assembly in a first operative relationship; and b) at least a second surface against which the pin bears with the pin and quick release assembly in a second operative relationship. The first and second surfaces are spaced from each other along the lengthwise line. The shoring post further includes at least one repositionable member that is changeable selectively between: a) a locked state wherein the at least one repositionable member prevents the pin and quick release assembly from changing from the first operative relationship into the second operative relationship; and b) a released state wherein the pin and quick release assembly can be changed from the first operative relationship into the second operative relationship. 
     In one form, the first and second parts are tubular components that are telescopingly engaged, one within the other. 
     In one form, the at least one repositionable member is a pin. 
     In one form, the pin has a “C” shape. 
     In one form, the pin has a body that moves as one piece. The body has: a) a first leg that extends into the first post part and abuts to the quick release assembly to thereby limit movement of the first post part in the one lengthwise direction relative to the second post part; and b) a second leg that abuts to the quick release assembly with the pin in the locked state to thereby prevent the pin and quick release member from changing from the first operative relationship into the second operative relationship. 
     In one form, the first leg has a length with a central axis and the pin is changed between the locked and released states by moving around the central axis of the first leg. 
     In one form, the at least first and second surfaces are substantially flat and reside in planes that are substantially parallel to each other and orthogonal to the lengthwise line. 
     In one form, the shoring post has a central axis parallel to the lengthwise line and the quick release assembly has a body that is movable as one piece relative to the first and second post parts around the central axis of the shoring post. 
     In one form, the body defines the first surface and a diametrically opposite surface and the pin bears against both the first and diametrically opposite surfaces with the pin and quick release assembly in the first operative relationship. 
     In one form, the body defines the second surface and a diametrically opposite surface and the pin bears against both the second and diametrically opposite surfaces with the pin and quick release assembly in the second operative relationship. 
     In one form, the body has a shape that is symmetrical so that the body interacts with the pin in the operative position in the same manner with the body in each of: a) one angular position; and b) a second angular position turned relative to the pin through 180° around the central axis of the shoring post from the one angular position. 
     In one form, the shoring post has a central axis parallel to the lengthwise line and the quick release assembly has spaced walls bounding the second surface that abut to the pin with the pin and the quick release assembly in the second operative relationship to confine opposite relative angular movement between the first post part and quick release assembly around the central axis. 
     In one form, the shoring post has a central axis parallel to the lengthwise line and the quick release assembly has a wall that abuts to the pin with the pin and the quick release assembly in the first operative relationship to block angular movement of the first post part in one direction around the central axis relative to the quick release assembly. 
     In one form, the pin has a body that is movable as one piece and the body abuts to the wall with the pin and the quick release assembly in the first operative relationship and the repositionable member in the locked state to thereby block angular movement of the first post part oppositely to the one direction relative to the quick release assembly. 
     In one form, the shoring post has a central axis parallel to the lengthwise line and the quick release assembly has a surface with a face to be impacted by a force along a first line and a force imparted to the face along the first line has a component that urges the quick release assembly in movement around the central axis. 
     In one form, the quick release assembly has a body that moves as one piece around the central axis and the body has a block upon which the face is defined. 
     In one form, the face projects radially to outside of the first and second post parts. 
     The invention is further directed to a method of using a shoring post. The method includes the steps of: providing a shoring post as set forth above; with the pin in the released state, placing the shoring post in compression between facing surfaces with the pin and quick release assembly in the first operative relationship; with the pin and quick release assembly in the first operative relationship, changing the pin from the released state into the locked state by turning the pin around the central axis of the first leg; changing the pin from the locked state back into the released state; and changing the pin and quick release assembly from the first operative relationship into the second operative relationship. 
     In one form, the step of providing a shoring post involves providing a shoring post with a central axis parallel to the lengthwise line and a quick release assembly having a body that is movable around the central axis as one piece. 
     In one form, the step of changing the pin and quick release assembly from the first operative relationship into the second operative relationship involves producing a sharp impact force upon the body of the quick release assembly that causes the body of the quick release assembly to turn around the central axis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a conventional shoring post operatively assembled between vertically spaced surfaces and including joinable first/upper and second/lower post parts and a pin for maintaining a desired relationship between the post parts; 
         FIG. 2  is an enlarged, perspective view of the upper portion of the shoring post in  FIG. 1 ; 
         FIG. 3  is an enlarged, exploded, perspective view of the shoring post in  FIG. 1 ; 
         FIG. 4  is a view as in  FIG. 1  of a shoring post, according to the present invention, having a first/upper part, a second/lower part and a pin, and incorporating a quick release assembly; 
         FIG. 5  is an enlarged, perspective view of the upper portion of the shoring post in  FIG. 4 ; 
         FIG. 6  is an enlarged, exploded, perspective view of the shoring post in  FIG. 4 ; 
         FIG. 7  is an enlarged, perspective view of the shoring post in  FIG. 4  with the pin and quick release assembly in a first operative relationship and with the pin in a locked state; 
         FIG. 8  is a view as in  FIG. 7  with the pin in a released state and the pin and quick release assembly in a second operative relationship; 
         FIG. 9  is an enlarged, elevation view of the shoring post in the  FIG. 7  state; 
         FIG. 10  is a view as in  FIG. 9  with the shoring post turned through 90° around a vertical axis. 
         FIG. 11  is a view as in  FIG. 10  with the shoring post turned an additional 90°; 
         FIG. 12  is a view as in  FIG. 9  with the shoring post in the  FIG. 8  state; 
         FIG. 13  is a view as in  FIG. 12  with the shoring post turned through 90° around the vertical axis; 
         FIG. 14  is a view as in  FIG. 13  with the shoring post turned an additional 90°; 
         FIG. 15  is an enlarged, perspective view of the pin on the inventive shoring post; 
         FIG. 16  is an enlarged, top perspective view of the quick release assembly on the inventive shoring post; 
         FIG. 17  is an enlarged, bottom perspective view of the quick release assembly; 
         FIG. 18  is an enlarged, plan view of the quick release assembly; 
         FIG. 19  is an enlarged, elevation view of the quick release assembly; 
         FIG. 20  is a schematic representation of cooperating post parts usable according to the present invention; 
         FIG. 21  is a perspective view of a shoring post as in  FIG. 4  and with the shoring post in an inverted orientation and incorporating a retainer assembly for the shoring post parts; 
         FIG. 22  is an enlarged, fragmentary perspective view of a portion of the shoring post in  FIG. 21  whereat the retainer assembly is incorporated; and 
         FIG. 23  is a fragmentary perspective view of a modified form of shoring post with a quick release assembly, according to the present invention, incorporated. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In  FIGS. 1-3 , a conventional shoring post is shown at  10  with a length adjusting capability. The shoring post  10  consists of a first, upper post part  12  and a second, lower post part  14 . The post parts  12 ,  14  are telescopingly mated to allow the effective overall length of the shoring post  10 , as indicated by the double-headed arrow  16 , to be selectively varied. 
     The lower post part  14  includes an extension sleeve  18  that fits over the upper free end  20  of a tubular component  22  making up the post part  14 . The tubular component  22  has external threads  24  that engage internal threads  26  on the post part  14 . By turning the extension sleeve  18  around a vertical, central axis  28  for the shoring post  10 , the extension sleeve  18  can be shifted selectively upwardly and downwardly relative to the component  22 , depending upon the turning direction. Handles  30  at diametrically opposite locations on the extension sleeve  18  facilitate grasping and turning of the extension sleeve  18 . 
     A washer  32  surrounds the post part  12  and bears upon the upper edge  34  of the extension sleeve  18 . 
     The shoring post  10  is designed to be loaded in compression in a vertical direction between an underlying surface  36  and a spaced, oppositely facing surface  38  on a component  40  residing above the surface  36 —typically a horizontal beam. However, the nature of the component  40  is not critical to the present invention, as it is contemplated that the shoring post  10  might be utilized in any environment in which a vertical compressive support is required, be it in the construction field or elsewhere. 
     The top of the post part  12  carries a bearing plate  42  with a surface  44  to act against the surface  38  on the component  40 . A like bearing plate  46  is provided at the bottom of the component  22  and has a surface  48  to facially engage the underlying surface  36 . 
     To install the shoring post  10 , a tubular component  50  on the post part  12  is mated with the tubular component  22  on the post part  14  by placing the components  22 ,  50 , one within the other, to permit sliding guided movement therebetween along a lengthwise line parallel to the central axis  28 . The post parts  12 ,  14  are situated so that their combined length nominally matches, while being slightly less than, the distance between the surfaces  36 ,  38 . Once this relationship is achieved, a C-shaped pin  52  is assembled into an operative position by directing a leg  54  thereon through the one of three vertically spaced openings  56   a,    56   b,    56   c  exposed in closest proximity to the washer  32 . The leg  54  has sufficient length to project diametrically oppositely from the post part  12  and thereby span across the diameter of the washer  32 . Oppositely projecting pin portions  58 ,  60  bear upon the upper edge  62  of the washer  32  at diametrically opposite locations. The washer  32  in turn bears upon the upper edge  34  of the extension sleeve  18 . 
     The number and vertical spacing of the openings  56   a,    56   b,    56   c  dictates the degree of length adjustment permitted and also the incremental length change from one opening to the next. Once the leg  54  has been directed into the appropriate opening to set a gross length adjustment matched to, but slightly less than, the distance between the surfaces  36 ,  38 , the extension sleeve  18  can be turned to increase the effective length of the post part  14  so as to exert a compressive loading force between the surfaces  36 ,  38 . 
     In  FIGS. 4-19 , a shoring post  70 , according to the present invention, is shown. The only difference between the shoring post  10  and the inventive shoring post  70  is that the inventive shoring post  70  has a quick release feature, as hereinafter described in greater detail. Parts on the shoring post  70 , corresponding to those shown on the shoring post  10 , will be identified with the same reference numerals herein. 
     As in the prior art shoring post  10 , the shoring post  70  has the first and second, upper and lower, post parts  12 ,  14  that are slidably guidingly relative to each other along the lengthwise line  16 , parallel to the central axis  28  of the shoring post  70 , to cooperatively define a variable effective length between the surfaces  44 ,  48  on the bearing plates  42 ,  46 , respectively. 
     It should be understood that while the post parts  12 ,  14  are shown to have mating, telescopingly engaged, tubular components  22 ,  50 , the invention contemplates other configurations for the first and second post parts, as shown schematically at  64  and  66  in  FIG. 20 .  FIG. 20  is intended to encompass any cooperating post parts that are guided relative to each other to cooperatively define variable effective lengths. 
     A quick release assembly  72  substitutes for, or alternatively can be used in conjunction with, the aforementioned washer  32 . In the depicted embodiment, the quick release assembly  72  is used by itself without a washer. 
     The post parts  12 ,  14  are joined as previously described, with the quick release assembly  72  surrounding the tubular component  50  and abutting the upper edge  34  of the extension sleeve  18 . The quick release assembly  72  may be made with one or multiple pieces. In this embodiment, the quick release assembly  72  has a body  74  that moves as one piece relative to each of the post parts  12 ,  14  around the central axis  28 . 
     With the post parts  12 ,  14  relatively positioned to produce a desired combined length, the leg  54  is directed through the exposed opening  56   a,    56   b,    56   c  closest to the quick release assembly  72 . Once the leg  54  on the pin  52  is extended into the post part  12  to an operative position, under the weight of the post part  12 , the pin  52  abuts to the quick release assembly  72 , thereby to limit movement of the first post part  12  downwardly along the axis  28  relative to the second post part  14 . As on the shoring post  10 , the pin  52  has portions  58 ,  60  that project oppositely from the post part  12  to engage the body  74  of the quick release assembly  72  at diametrically opposite locations. 
     The body  74  has a first surface  76  against which the pin leg  54  bears with the pin  52  and quick release assembly  72  in a first operative relationship, as shown in  FIG. 7 . A second surface  78  is defined by the body  74  against which the pin  52  bears with the pin  52  and quick release assembly  72  in a second operative relationship, as shown in  FIG. 8 . The first and second surfaces  76 ,  78  reside in parallel planes that are spaced from each other a distance X (see  FIG. 19 ) along a lengthwise line parallel to the central shoring post axis  28 . The surfaces  76 ,  78  are shown to be parallel to each other and orthogonal to the axis  28 , though this is not required. 
     For stability purposes, the pin  52  is made with an optional flat  79  ( FIG. 15 ) on the side thereof that abuts to the quick release assembly  72 . 
     While a single first surface  76  and a single second surface  78  might perform adequately, in a preferred form, the first surface  76  has a diametrically opposite counterpart  76 ′, with the second surface  78  having a corresponding diametrically opposite surface  78 ′. The design of the body  74  is such that the pin portions  58 ,  60  engage one each with the first surfaces  76 ,  76 ′ with the pin  52  and quick release assembly  72  in the first operative relationship. The portions  58 ,  60  engage one each with the second surfaces  78 ,  78 ′ with the pin  52  and quick release assembly  72  in the second operative relationship. 
     The body  74  has a shape that is symmetrical so that the body  74  interacts with the pin  52  in the operative position in the same manner with the body  74  in each of: a) one angular position; and b) a second angular position turned through 180° around the central axis  28  of the shoring post  70  from the one angular position. Thus, depending upon the orientation for the body  74 , the portions  58 ,  60  of the pin leg  54  will engage one or the other of the surfaces  76 ,  78 ;  76 ′,  78 ′. As a result, to set up the shoring post  70 , the installer is not required to turn the body  74  relative to the post part  12  through more than 180° to align the pin  52  over the first surfaces  76 ,  76 ′. 
     The quick release assembly  72  is configured to cooperate with at least one repositionable member that is changeable selectively between: a) a locked state wherein the at least one repositionable member prevents the pin  52  and quick release assembly  72  from changing by relative angular movement around the axis  28  from the first operative relationship into the second operative relationship; and b) a released state wherein the pin  52  and quick release assembly  72  can be changed by relative angular movement around the axis  28  from the first operative relationship into the second operative relationship. While it is contemplated that the at least one repositionable member can be a single component, or multiple components, separate from the pin  52 , in this embodiment, the pin  52  defines the at least one repositionable member. 
     More particularly, the pin  52  has a body  80  that is formed into a “C” shape. The pin body  80 , which moves as one piece, and in this case is formed from a single piece of cylindrical stock, consists of: a) the leg  54  that extends into the first post part  12  and abuts to the quick release assembly  72  to thereby limit movement of the first post part  12  in one lengthwise direction relative to the second post part  14 ; and b) a second leg  82  that abuts to the quick release assembly  72  with the pin  52  in the locked state to thereby prevent the pin  52  and quick release assembly  72  from changing from the first operative relationship of  FIG. 7  into the second operative relationship of  FIG. 8 . 
     The first leg  54  has a length with a central axis  84 . The pin  52  is changed between the locked and released states therefor by moving the body  80  of the pin  52  around the central axis  84  of the first leg  54 . 
     To assembly the shoring post  10 , the pin  52  is placed in the released state, as shown in FIGS.  8  and  12 - 14 . The body  80  is angularly oriented so that the pin leg  54  spans across the first surfaces  76 ,  76 ′. The pin  52  can then be pivoted around the leg axis  84 , thereby to place the pin  52  in its locked state. 
     The pin portions  58 ,  60  interact with the body  74  in the same manner at diametrically opposite locations. With the pin  52  in its locked state, the exemplary pin portion  60  is confined to angularly align over the first surface  76 . Turning of the post part  12  relative to the body  74  in one direction around the axis  28 , as indicated by the arrow  86  in  FIG. 8 , is limited by an edge  88  on a wall  90  to which the pin portion  60  is abuttable. Turning of the post part  12  in the opposite direction around the axis  28 , as indicated by the arrow  92 , causes the pin leg  82  to abut to a surface  96  on the wall  90 . The leg portion  58  cooperates with a corresponding wall  90 ′ in like fashion, with it being understood that the body  74  could be reversed by rotation around the axis  28  relative to the post part  12  and pin  52 . 
     In this embodiment, the pin leg  82  is substantially straight and joined to the pin leg  54  through a curved bight portion  98 . This particular configuration is not critical, so long as the chosen shape permits the described interaction between the pin  52  and quick release assembly  72 . 
     With the described arrangement, the wall  90  becomes loosely captive between the pin legs  54 ,  82 , thereby avoiding inadvertent shifting of the pin portion  60  off of the first surface  76  and shifting of the corresponding pin portion  58  off of the first surface  76 ′, so long as the pin  52  is maintained in its locked state. 
     With the pin  52  in its released state, the post part  12  and quick release assembly  72  can be relatively turned around the axis  28  to allow the pin portions  58 ,  60  to angularly shift from the first surfaces  76 ,  76 ′ to align over, and drop down against, the second surfaces  78 ,  78 ′, as a result of which the effective length of the shoring post  70  is reduced by the height of the step X between the surfaces  76 ,  76 ′;  78 ,  78 ′, thereby diminishing the compressive force produced between the surfaces  36 ,  38 . 
     With the pin portions  58 ,  60  against the surfaces  78 ,  78 ′, angular movement of the pin  52  relative to the quick release assembly  72  is confined by a surface  100  on the wall  90 ′ and a separate, spaced surface  102  on a wall  104  upon which the first surface  76  is defined. The surfaces  100 ,  102  bound the surface  78  at angularly spaced locations. The pin  52  is confined angularly over the second surface  78 ′ by corresponding surfaces  100 ′,  102 ′. 
     Blocks  104 ,  104 ′ are defined on the body  74  at diametrically opposite locations. Exemplary block  104  has an exposed surface  106  defining a face to be impacted by an object to generate a force along a first line  108  that is generally orthogonal to the surface  106 . A force imparted to the surface  106  along the first line  108  has a component that urges the quick release assembly  72  in a direction of the arrow  110  ( FIG. 18 ) around the central axis  28 . The surface  106 , and the diametrically opposite surface  106 ′, project radially to outside of the post parts  12 ,  14  to be accessible, as to be struck by a hammer or other weighted object  112 . Through this action, the pin  52  and quick release assembly  72  can be instantaneously changed from their first operative relationship into their second operative relationship to reduce the compressive loading force produced by the shoring post  70 . 
     With the above structure, the shoring post  70  can be installed as follows. With the pin  52  in its released state, the shoring post  70  can be placed in compression between the facing surfaces  36 ,  38  with the pin  52  and quick release assembly  72  in the first operative relationship. Thereafter, the pin  52  can be changed from the released state into the locked state by turning the pin  52  around the axis  84  to maintain the first operative relationship between the pin  52  and quick release assembly  72 . The shoring post  70  will maintain this configuration to allow the appropriate task(s) to be performed. 
     Thereafter, to reset or disassemble the shoring post  70 , the pin  52  is changed from its locked state into its released state, after which the pin  52  and quick release assembly  72  can be changed from their first operative relationship into their second operative relationship. As this occurs, the pin leg  54  changes angular alignment from over the first surfaces  76 ,  76 ′ to over the second surfaces  78 ,  78 ′. Residual compressive forces in the shoring post  70  cause the pin leg  54  to shift downwardly, thereby incrementally changing the effective length of the shoring post  70  by the distance X, which may be on the order of ½ inch. This distance X may be greater or less depending upon the particular application. 
     As noted above, with the shoring post  70  placed in compression, the quick release assembly  72  is squeezed captively between the pin leg  54  and the quick release assembly  72 . Thus, a significant impact force produced, as through a hammer, may be required to turn the quick release assembly  72  relative to the pin  52 . 
     In some applications, the shoring post  70  may be on the order of fourteen feet in length. With the depicted configuration, the extension sleeve  18  is at a height that it is not reachable to be turned by an individual standing at ground level. To address this problem, the shoring post  70  is shown in  FIGS. 21 and 22  to be inverted from the  FIG. 4  orientation so that the extension sleeve  18  is closer to the bottom of the shoring post  70  than the top thereof. The basic length adjustment and quick release are effected as described above; however, provision must be made to keep the post parts  12 ,  14  from separating. 
     For this purpose, a retainer assembly  200  is incorporated. The retainer assembly  200  comprises a body  202  with diametrically oppositely located supporting arms  204 ,  206 , each with a generally “L” shape. Exemplary supporting arm  204  has a vertical leg  208  and a horizontal leg  210  that bears against a radially enlarged, annular flange  212  on the extension sleeve  18 . The leg  208 , and a like leg  208 ′ on the supporting arm  206 , cooperatively block downward movement of the body  202  relative to the extension sleeve  18 . 
     The body  202  has at least one, and preferably two, locking extensions  214 ,  214 ′ each defining a bearing edge  216  (for exemplary blocking extension  214 ) that abuts to the projecting portion  60  of the pin  52 . The other projecting portion  58  (not shown) cooperates with the blocking extension  214 ′ in like fashion. 
     Through this arrangement, with the shoring post in the orientation in  FIGS. 21 and 22 , the post part  12  is prevented from sliding unrestrained downwardly relative to the post part  14  as would otherwise allow the post part  12  to eventually separate from the post part  14 . 
     In  FIG. 23 , a further modified form of shoring post is shown at  300 . The shoring post  300  has a first post part  302  that slides within a second post part  304 . The post parts  302 ,  304  are configured complementarily in cross section so that they are keyed against relative turning around a vertical central axis from the shoring post  300 . 
     In this embodiment, the post part  302  has circumferentially spaced rows of threads  304  that are cooperatively engaged by a star-shaped, threaded extension nut  306  that is turned relative to the post part  302  around the central shoring post axis to change its vertical location upon the post part  302 . 
     The extension nut  306  has an associated support plate  308  with an upper surface  309  upon which a quick release assembly  310 , corresponding to the quick release assembly  72 , bears. The quick release assembly  310  has an annular body portion with circumferentially spaced steps  311 , each with an upper support surface  312 . Between adjacent steps  311 , a lower support surface  314  is defined. A ramp surface  316  transitions between the upper support surface  312  on one step  311  and a lower support surface  314 , with the lower support surface  314  extending to a blocking surface  320  on the adjacent step  311 . Receptacles  322  are thus formed, each bounded by a ramp surface  316 , a lower support surface  314 , and a blocking surface  320 , and located in spaced relationship around the circumference of the annular body portion. 
     The post part  304  has a base component  322  with extensions  326  that are each complementary in shape to the receptacles  322 , with a plurality of the extensions  326  preferably each cooperating with a receptacle  322  in like fashion. More specifically, each extension  326  has a ramp surface  330 , a lower support surface  332 , and a blocking surface  334 . By turning the quick release assembly  310  in the direction of the arrow  336 , the ramp surfaces  316 ,  330  coincide and progressively guide each extension  326  downwardly into its respective receptacle  322 , as an incident of which the post part  304  moves downwardly an increment corresponding to the depth of the receptacles  322 . 
     Diametrically opposite blocks  340 ,  340 ′ are provided and correspond generally in structure and function to the blocks  104 ,  104 ′ previously described. 
     By turning the extension nut  306 , the effective length of the shoring post  300  can be selected with the extension  326  angularly aligned to be supported upon the upper support surfaces  312 , as shown in  FIG. 23 . The blocks  340 ,  340 ′ can then be impacted to turn the quick release assembly  310 , thereby to cause the extensions  326  to move into the receptacles  322  and incrementally shorten the shoring post  300 , as to facilitate its removal. 
     The foregoing disclosure of specific embodiments is intended to be illustrative of the broad concepts comprehended by the invention.