US3676972A

US3676972A - Shoring structure

Info

Publication number: US3676972A
Application number: US846759A
Authority: US
Inventors: Clayton R Ballou
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-08-01
Filing date: 1969-08-01
Publication date: 1972-07-18
Anticipated expiration: 1989-07-18

Abstract

Disclosed herein are shorting structures having bases and telescoping members, each shoring structure being fabricated of square tubing. In one embodiment of the structure, square tubing of the telescoping member telescopes inside and along square tubing of the base. In a second embodiment, square tubing of the telescoping member telescopes outside and along square tubing of the base member. In yet another embodiment both inner and outer square tubing of the telescoping member telescopes along square tubing of the base. Lock means are associated with the bases and telescoping members to lock thereto cross bracing between base members, telescoping members, etc. Such lock means include a slidable member which is slidable to a position holding the end portion of a cross brace, and to a position freeing the end portion of the cross brace.

Description

United States Patent Ballou [54] SHORING STRUCTURE Clayton R. Ballou, San Ramon, Calif.

Jack E. Hursh, Millbrae, Calif. a part interest [22] Filed: Aug. 1, 1969 [21] Appl.No.: 846,759

[72] Inventor:

[73] Assignee:

52 use: ..52/638,52/645,248/354P s1 .1041 12/00 58 FieIdofSearch ..182/178, 179; 52/645, 646,

[56] References Cited UNITED STATES PATENTS 3,292,891 12/1966 Williams ..248/125 x 1,184,455 5/1916 l-[ough ..248/l88..5 3,190,405 6/1965 Squire ..52/655 X 3,302,749 2/1967 Heaphy et a1. ...182/178 X 3,481,095 12/1969 Beziat 1 ..52/638 3,508,666 4/1970 Schwengel ..182/178 X [451 July 18, 1972 FOREIGN PATENTS OR APPLICATIONS 364,814 l/1932 Great Britain ..248/354 P 671,903 5/1952 Great Britain.... ..248/408 752,230 7/1933 France .248/354 P 1,031,787 6/1966 Great Britain 1 82/1 78 1,188,571 3/1959 France ..182/178 Primary Examiner-Dennis L. Taylor Attorney-Mellin, Moore & Weissenberger [57] ABSTRACT Disclosed herein are shorting structures having bases and telescoping members, each shoring structure being fabricated of square tubing. In one embodiment of the structure, square tubing of the telescoping member telescopes inside and along square tubing of the base. In a second embodiment, square tubing of the telescoping member telescopes outside and along square tubing of the base member. In yet another embodiment both inner and outer square tubing of the telescoping member telescopes along square tubing of the base.

Lock means are associated with the bases and telescoping members to lock thereto cross bracing between base members, telescoping members, etc. Such lock means include a slidable member which is slidable to a position holding the end portion of a cross brace, and to a position freeing the end'portion of the cross brace.

3 Clains, 21 Drawing Figures //95c k 921x PATENTEUmwm-z 3.676.972

sum 1 OF 5 INVENTOK CLAYTON R. BALLOU m r-W ATTORNEYS PATENTED JUL 1 8 I972 SHEET 2 OF 6 I NV ENTOR.

FlG 2 CLAYTON R. BALLOU ATTORNEYS PATENTED JUL] 8 I972 SHEET 3 UF 6 FlG 8 INVENTOR.

CLAYTON R, BALLOU FlG 5 ATTORNEYS PATENTED JuL18|912 3.676372 sum u 0F 6 HI I (938 SW F!G 13 i ll] H I04 FlG 14 INVENTOR.

CLAYTON R. BALLOU ,WP l/ F lG 1O F lG. ll ATTORNEYS PATENTEU JUL 1 8 I972 SHEET 8 BF 6 F l G 2 1 INVENTOK Y CLAYTON R. BALLOU Wow 2am 0741 ATTORNEYS SHORING STRUCTURE BACKGROUND OF THE INVENTION This invention relates to shoring structures and, more particularly, to such a shoring structure which utilizes a telescoping member which may be set at a variety of heights.

In the shoring of, for example, overpass roads which are being built, it is well known to provide a series of shoring structures, each having a lower base, and a telescoping upper frame member which may be set at one of a variety of heights, depending on the height of the load to be shored. Generally, the common shoring structure is fabricated of tubing of round cross section, and the upper frame member has a pair of parallel tubular legs which are slidably positioned within a pair of parallel tubular legs which comprise part of the base. Means are included to selectively set the telescoping member at its proper height.

Because of the uses of such shoring structures, it is, of course, extremely important that it be quite strong, and so improvements in this direction are constantly being sought. An especially critical area is the telescoping member itself, and its interconnection with the base member. While the structure overall should be extremely strong, it should be designed so that telescoping can be easily and conveniently achieved. Above and beyond this, each overall shoring structure should be as simple and easy to use as possible.

As stated previously, a series of shoring structures of the type described are often used. In such circumstance, brace members interconnect the shoring structures, so that the overall resulting structure is strong and stable. The ends of these brace members should be properly fixed to the shoring structures by convenient means to provide proper bracing, but should be easily and conveniently removable therefrom so that the shoring may be taken down quickly and easily when no longer needed.

Finally, when it is necessary for the shoring structure to be built up to a relatively great height, means should be provided to allow bases to be stacked one on top of the other in a safe, strong and convenient manner. On top of these may then be placed a telescoping member, to provide the close adjustment in height previously described.

It is therefore an object of this invention to provide a shoring structure which (i) includes a telescoping member which can be easily and conveniently adjusted, and (ii) is of such overall design as to have extremely great load-bearing qualities.

It is a further object of this invention to provide means for securing interconnecting brace members to a pair of shoring structures by means which securely hold the brace members when required, yet can easily be manipulated to allow the brace members to be easily and conveniently removed.

It is a still further object of this invention to provide means which allow bases to be stacked one on top of the other in a safe, strong and convenient manner.

SUMMARY OF THE INVENTION Broadly stated, the invention shoring structure comprises a base having a pair of generally parallel, tubular legs of square cross section, with cross bracing of square cross sections and a telescopic frame member having a pair of generally parallel, tubular legs of square cross section slidable along the legs of the base, either inside or outside thereof, so that the telescopic frame member is slidable inwardly and outwardly of the base. Each leg of the telescopic frame member has a plurality of spaced apertures therethrough. Further included are first and second pins, the first pin being positionable in any one of the apertures in one leg of the frame member, the second pin being positionable in the corresponding aperture of the other leg of the frame member. Means are associated with the legs of the base to limit the inward sliding of the frame member relative to the base by blocking the pins positioned in their respective apertures.

This invention further comprises a lock for securing the end portion of a longitudinal cross member relative to a frame portion. Such lock comprises a support member fixed to the frame portion, and a shaft fixed to and extending from the support member, the end portion of the longitudinal member being positionable so that the shaft is disposed through an aperture through said end portion of the longitudinal member. A slidable member is associated with the support member and slidable relative thereto. An arm is fixed to and extends from the slidable member, the slidable member being slidable to a first position where the end of the am is removed from the shaft to freely allow the end portion of the longitudinal member to be positioned so that the shaft is disposed through the aperture, and to freely allow removal of the portion of the longitudinal member from such position, the slidable member being slidable to a second position where the end of the arm is adjacent the shaft, so that the movement of the portion of the longitudinal members from said position with the shaft disposed through the aperture is limited by the arm.

This invention further comprises a frame structure, comprising a first longitudinal upright tube of generally square cross section, and a second longitudinal upright tube of generally square cross section above the first tube and aligned therewith, and having its lower end positioned adjacent the upper end of the first tube. A rigid connecting bar defines an upper portion disposed in the lower end of the second tube, a lower portion of the connecting bar disposed in the upper end of the first tube, and a circumferential lip thereabout intermediate the upper and lower portions of said connecting bar, which rests on the upper end of the first tube, and on which rests the lower end of the second tube.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of the invention will become apparent from a study of the following specification and drawings, in which:

FIG. 1 is an overall perspective view of a pair of base shoring structures interconnected by brace members in accordance with the invention;

FIG. 2 is a front elevation of a shoring structure of FIG. 1 with a first embodiment of telescoping frame member;

FIG. 3 is a view taken along the line 3-3 of FIG. 2, with a portion broken away;

FIG. 4 is a sectional view taken along the line 44 of FIG.

FIG. 5 is a view similar to that of FIG. 2, but with a second embodiment of telescoping frame member;

FIG. 6 is a view taken along the line 6-6 of FIG. 5, with a portion broken away;

FIG. 7 is a view taken along the line 7-7 of FIG. 6, with portions removed;

FIG. 8 is a sectional view taken along the line 8-8 of FIG.

FIG. 9 is a view similar to that of FIGS. 2 and 5, but with a third embodiment of telescoping frame member, and with a portion of the base removed;

FIG. 10 is a front elevation of a leg of the telescoping frame member of FIG. 9 partially broken away, and with a portion removed;

FIG. 11 is a side elevation of the leg of FIG. 10;

FIG. 12 is a sectional view taken along the line 12l2 of FIG. 10;

FIG. 13 is a sectional view taken along the line l3l3 of FIG. 10;

FIG. 14 is a sectional view taken along the line l414 of FIG. 1 l, rotated FIG. 15 is a front elevation of a pair of bases, one stacked on the other;

FIG. 16 is a view taken along the line 1616 of FIG. 15, with portions broken away;

FIG. 17 is a sectional view taken along the line 17l7 of FIG. 16;

FIG. 18 is a perspective view of the look as used in FIG. 1 to lock the cross brace members to a series of bases;

FIG. 19 is a side elevation of the lock of FIG. 18;

FIG. 20 is afront elevation of the lock of FIGS. 18 and 19;

FIG. 21 is a plan view of the lock of FIGS. 18-20.

DESCRIPTION OF THE PREFERRED EMBODIMENT Shown generally in FIG. 1 is a shoring system made up of a pair of shoring

structures

12, 14 interconnected by longitudinal cross brace members l6, 18, 20, 22. Each shoring structure, such as shoring structure 12, is made up of a base 24, and a telescoping frame member 26. Such a shoring structure 12 is shown in detail in FIGS. 2-4.

As shown therein, base 24 has a pair of generally

parallel legs

28, 30 which are interconnected by

cross members

32, 34, 36, 38, so as to be rigidly positioned relative to each other. Above the base 24 is a telescopic frame member 40, which also has a pair of generally

parallel legs

42, 44 which are interconnected and reinforced by braces 43A, B, C and D. The

legs

28, 30, 42, 44 are each square in cross section, as are braces 43A, B, C and D, and are actually tubular in configuration. The cross sections of

legs

42, 44 are such that the

legs

42, 44 are positionable within the inner bores of the

tubular legs

28, 30. The positioning of leg 44 within inner bore 30A of leg 30 is shown in FIGS. 3 and 4, it being understood that

legs

28, 42 cooperate in the same manner. A certain amount of clearance is provided between

legs

42, 44 and the inner bores of

legs

28, 30 respectively, so that the

legs

42, 44 are slidable inside and along the

legs

28, 30. Thus the telescopic frame member 40 is slidable inwardly and outwardly of the base 24.

Leg 42 has a plurality of spaced apertures 46 therethrough, and leg 44 has a corresponding plurality of spaced apertures 48 therethrough. Each of the

apertures

46, 48 is square in cross-section. A pair of blocking

members

50, 52 are positioned on the top ends 29, 31 of

legs

28, 30 of base member 24. One such blocking member 52 is shown in detail in FIGS. 3 and 4. As shown therein, blocking member 52 has a downwardly extending edge 54 which surrounds the top end 31 of leg 30, and has an aperture 55 therethrough allowing free sliding of leg 44 therethrough. A pin 56 of square cross section is positionable in any of the apertures 48 through leg 44, and, as leg 44 is lowered, a flat side 56A of pin 56 will bear against blocking member 52, sitting in a flat recess 58 provided therefor, so as to limit the inward sliding of leg 44 relative to leg 30.

A similar pin 60 of square cross section is positionable in any of the apertures 46 through leg 42, and cooperates with blocking member 50 in a similar manner. In this way, the inward sliding of the telescopic frame member 40 relative to the base 24 may be limited with the telescopic frame member 40 at a desired height.

A second embodiment of telescopic frame member 70, associated with a base 24 as previously described, is shown in FIGS. 5-8. As shown therein, telescopic frame member 70 has a pair of generally

parallel legs

72, 74 of square cross-section which are interconnected and reinforced by bracing 73A, B, C and D of square cross-sections. Leg 74 and its association with leg 30 of base 24 are shown in detail in FIGS. 6-8. As shown therein, leg 74 defines an inner bore 74A, and leg 30 of base 24 is positioned within that inner bore 74A, with a small clearance therebetween. In this way, leg 74 is slidable outside and along leg 30 of the base 24, with a longitudinal gap 76 being provided in leg 74 to allow clearance for the ends of

cross members

32, 34, 36, 38 of base 24. It will be understood, of course, that leg 72 is associated with leg 28 in a similar manner.

Leg 74 has a plurality of spaced apertures 80 therethrough, and leg 72 has a plurality of spaced apertures 78 therethrough. Each of the

apertures

78, 80 is square in cross section, as shown.

A pin 82 of square cross section is positionable in any of the apertures 80, and a flat surface 82A thereof will bear on the flat top end 31 of leg 30, so as to limit inward sliding of leg 74 relative to leg 30. A similar pin is positionable in any of the apertures 78, and cooperates with the top end 29 of leg 28 in a similar manner. In this way, the inward sliding of telescopic frame member 70 relative to base 24 may be limited, with the telescopic frame member 70 held at a desired height.

A variation of telescopic frame member 70 is shown in FIGS. 9-14. As shown therein, a telescopic frame member has

tubular legs

92, 94 of square cross section which are interconnected and reinforced by bracing 93A, B, C and D of square cross section.

Legs

92, 94 are slidable outside the

legs

28, 30 of a base 24, similar to telescopic frame member 70. As shown in detail in FIGS. 10-14, leg 92 has a spacer 96, of square cross section welded therewithin adjacent the top end thereof, and a tubular guide 98, of squarecross section, has its top end welded within the spacer 96. Guide 98 is thus spaced from the inner bore 100 of leg 92. Guide 98 extends downwardly below the bottom end of leg 92. In cooperation with the leg 28 of base 24, guide 98 is disposed within the inner bore 28A of leg 28, with the leg 28 itself within the inner bore 100 of leg 92. Leg 94 also includes a guide 102 associated therewith, which cooperates with leg 30 in a similar manner. Spaced apertures 104 of square cross section are provided through leg 92, and spaced apertures 106 of square cross section are provided through leg 94. Guides 98, 102 define spaced

apertures

108, 110 of square cross section which cooperate with

apertures

104, 106, so that pins of square cross section, such as pin 112, can be disposed therethrough, and will rest with flat surfaces thereof flush against the flat top ends 29, 31 of

legs

28, 30 to limit the inward telescoping of telescopic frame member 90.

The shoring structures as disclosed may be set at a variety of heights, and may be used in a series in cooperation with jack means (not shown) if they are on uneven ground, as is well known.

The particular advantages of these designs should be noted. First, since each embodiment is fabricated of square tubing, it is extremely strong. Each embodiment is also quite easy to manufacture, when compared with shoring of round tubing. When using round tubing, each end of a cross-tube must be particularly cove cut to mate with the rounded surface of the tube to which it is to be joined, or each end must be smashed to flatten it out so that it can be welded. The former is obviously disadvantageous, as it is quite time-consuming, and the latter has been found to create cracks in the metal that can result in failure after welding, if the ends are smashed when cold. Heating the ends before smashing is expensive and timeconsuming, and is generally not done.

In fabricating a shoring structure of tubing of square cross section, only one straight cut need be made on each end of a cross tube, so that it will mate with the flat surface of the tube of square cross section to which it is to be joined. Also adding to the strength of the structure is the fact that no holes need be punched in the base of any embodiment.

In addition, the load-supporting pins are square in cross section, and set in square apertures, with flat surfaces thereof engaging with flat bearing surfaces. Because of this design, the load on the telescopic frame member is distributed over a flat area, ensuring that the shear load capacity of the pin is very high. As a comparison, if the pin were round, the loaded area would be smaller, and in fact could well be a single point if the pin is disposed in a slightly oversize round aperture. In such case, many failures occurred because of the splitting of the tubing by this single point contact.

In any of the embodiments, it will be seen, telescoping of the frame member, and then setting it at its chosen height can be easily and conveniently achieved, merely by removing the pins, sliding the frame member, and reinserting the pins in the chosen apertures.

In particular, the blocking

members

50, 52 of the firstdescribed embodiment spread the load over the whole area of the top ends 29, 31 of the

legs

28, 30, providing even greater load-bearing qualities.

The provision of guide tubes 98, 102 as shown in the thirddescribed embodiment (FIGS. -14), provide a number of advantages. First, because of the double tube design of each leg, even greater strength is provided. Second, the load on each pin is spread over an even greater area, that is, that defined by apertures both in the leg and in the guide associated therewith. Third, the double tube structure, when cooperating with a leg of base 24, provides a rigidity between telescopic top frame member and base which does away with any need for connecting braces between the telescopic top frame member and base. Although the tubes of FIGS. 6-14 are shown as square in cross-section, the telescoping member may be adapted to a standard base having tubular legs of circular cross-section.

Shown in FIGS. -17 are means for stacking bases 24, 24' on top of each other to achieve greater overall shoring height. Such means are used in cooperation with upright tubes of square cross section, such as the legs 28, 28' and

legs

30, 30 of

bases

24, 24. Such means comprise a rigid bar 120, as shown associated with

tubular legs

30, 30, it being understood that a like bar is associated in a similar manner with

tubular legs

28, 28.

The rigid bar 120 defines an upper portion 122 which in turn defines four

longitudinal ribs

124, 126, 128, 130, a lower portion 132 defining four similar ribs, and a circumferential lip 134 intermediate the upper and

lower portions

122, 132. As shown, the

ribs

124, 126, 128, 130 defined by the upper portion 122, and the corresponding ribs defined by the lower portion 132, taper inwardly away from the circumferential lip 134. In use, the lower portion 132 of the bar 120 is disposed in the upper end of the leg 30 and the upper portion 122 of the bar 120 is disposed in the lower end of the leg 30, with the circumferential lip 134 resting on the end 31 of leg 30, and on which rests the lower end 33' of leg 30'. In such use, the

ribs

124, 126, 128, 130 are positioned in the

inner corners

136, 138, 140, 142 defined by the lower end of the square-tube leg 30'. Similarly, the ribs defined by lower portion 132 are positioned in the inner comers defined by the upper end of squaretube leg 30. It will be seen that such design allows bases to be stacked on one another in series in a very strong, stable manner. This is so because of the ribs which are positioned in the inner comers defined by the legs. The taper of these ribs ensures that there can be no binding between the upper and lower portions of the rigid bar and the lower and upper. ends of the legs.

As stated previously, FIG. 1 shows a pair of shoring

structures

12, 14 interconnected by

brace members

16, 18, 20, 22. Locks 200, fixed to the legs of the bases of shoring

structures

12, 14, are used to secure the end portions of the

longitudinal brace members

16, 18, 20, 22 to the legs of the bases. One of such locks 200, in cooperation with leg 30 of base 24, is shown in detail in FIGS. 18-21. Such lock 200 comprises a channel support member 202 fixed to leg 30 and defining an opening 204 therethrough. A shaft 206 is fixed to and extends from the support member 202. A slidable member 208 is disposed through the opening 204 defined by the support member and is slidable relative thereto.

The slidable member 208 has

arms

210, 212 fixed to and extending outwardly and toward each other from the ends thereof.

The slidable member is slidable to a first position (shown in full in FIG. 19) where the ends 214, 216 of

arms

210, 212 are removed from the shaft 206. When in such first position, the flattened end portion 22A of the longitudinal cross member 22 may be positioned so that the shaft 206 is disposed through an aperture 218 in the end portion 22A, and may be freely removed from such position. The slidable member 208 is also slidable to a second position (FIG. 18) where a portion 220 of the arm 210 adjacent the end 214 is positioned in a slot 222 in the shaft 206, so that the arm 210 extends from one side 224 of the shaft 206 to the other side 226, with the end 214 extending from the other side 226. In such second position, a nail or cotter pin 228 may be positioned through an opening 230 in the end 214 of the arm 210, to limit the movement of the end 214 of the arm 210 from its position on the other side 226 of the shaft 206. The slidable member 208 may thus be selectively held in its second position, whereby the end portion 22A of the longitudinal member 22 is locked on the shaft 206 by arm 210. Stop means 232 are included at one end of the slidable member 208 to contact the support member 202 to limit the sliding of the slidable member 208 in that direction, to define the second position of the slidable member.

The slidable member 208 is also slidable to a third position (shown in phantom in FIG. 19) where a portion 240 of the arm 212 is positioned in slot 222, so that the arm 212 extends from the other side 226 of the shaft 206 to the one side 224, with the end 216 extending from the one side 224. In such third position a nail or cotter pin, similar to cotter pin 228, may be positioned through an opening 242 in the end 218 of arm 212, to hold the arm 212 in such position, locking the end portion 22A of the brace member 22 on shaft 206. Similar to stop means 232, stop means 244 are included at the other end of the slidable member 208 to contact the support member 202 to limit the sliding of the slidable member 208 in that direction, to define the third position of the slidable member 208.

The base 222A of the slot 222 may be chamfered so that the

arms

210, 212 are raised to an extent as they are seated in slot 222. This provides a certain amount of springing in the

arms

210, 212, aiding in the locking action of the lock 200.

Such locks 200 as disclosed, where used throughout a shoring system such as that shown at 10 in FIG. 1, ensure a positive locking means for securing cross braces to the legs of the bases. The locks 200, it will also be seen, can be easily used to selectively lock or unlock such brace members, so that the overall shoring system may be built up, changed, or disassembled easily and conveniently.

Iclaim:

1. A shoring structure comprising:

a. a base having a pair of generally parallel tubular legs generally square in cross section;

b. a telescopic frame member having a pair of generally parallel tubular legs generally square in cross section slidable outside the legs of the base, with the legs of the base within the inner bores of the tubular legs of the telescopic frame member so that the telescopic frame member is slidable inwardly and outwardly of the base;

c. a pair of guides, one fixed within each leg of the telescopic frame member, of square cross section, and spaced from the inner bores of that leg, the guides being slidably disposed within the inner bores of the tubular legs of the base;

d. each leg of the telescopic frame member and the guide therein defining a plurality of spaced cooperating square apertures therethrough;

e. first and second pins each square in cross section, the first pin being positionable in any one of the apertures in one leg of the telescopic frame member and cooperating aperture of the guide associated therewith, the second pin being positionable in any one of the apertures of the other leg of the telescopic frame member and cooperating aperture of the guide associated therewith; and

f. means associated with the legs of the base to limit inward sliding of the telescopic frame member relative to the base by blocking the pins positioned in their respective apertures.

2. A shoring structure comprising:

a. a base having a pair of generally parallel tubular legs;

b. a telescopic frame member having a pair of generally parallel tubular legs slidable outside the legs of the base, with the legs of the base within the inner bores of the tubular legs of the telescopic frame member so that the telescopic frame member is slidable inwardly and outwardly of the base; each leg of the telescopic frame member having a plurality of spaced apertures therethrough;

c. a pair of guides, one fixed within each leg of the telescopic frame member, and spaced from the inner bore of that leg, the guides being disposed within the inner bores of the legs of the base, and defining spaced apertures therethrough cooperating with the spaced apertures through the legs of the telescopic frame member;

d. first and second pins, the first pin being positionable in any one of the apertures in one leg of the telescopic frame member and cooperating aperture of the guide associated therewith, the second pin being positionable in any one of the apertures of the other leg of the telescopic frame member and cooperating aperture of the guide associated therewith; and

e. means associated with the legs of the base to limit the inward sliding of the telescopic frame member relative to the base by blocking the pins positioned in their respective apertures.

3. A shoring structure comprising:

a. a base having a leg member which is elongated along an axis and defines a first bore;

b. a frame having a leg member which is elongated and extends coaxially with said base leg member, said leg member of said frame comprising a guide member and a tubular member defining a second bore surrounding said guide member, said leg member of said base being received within said second bore and said guide member being received within said first bore in telescopic relation thereto so that said frame leg member is slidable along said base leg member toward and away from said base;

c. one of said leg members having a square aperture extending therethrough normal to said axis, said aperture having one of its pairs of opposite sides normal to said axis;

d. a pin having a square cross section positioned in said aperture with its sides congruent with the sides of said aperture and projecting therefrom; and

e. flat surface means associated with the end of the other of said leg members in contact with a side of said pin to limit the sliding of said frame leg member toward said base.

a: a: s s s

Claims

1. A shoring structure comprising: a. a base having a Pair of generally parallel tubular legs generally square in cross section; b. a telescopic frame member having a pair of generally parallel tubular legs generally square in cross section slidable outside the legs of the base, with the legs of the base within the inner bores of the tubular legs of the telescopic frame member so that the telescopic frame member is slidable inwardly and outwardly of the base; c. a pair of guides, one fixed within each leg of the telescopic frame member, of square cross section, and spaced from the inner bores of that leg, the guides being slidably disposed within the inner bores of the tubular legs of the base; d. each leg of the telescopic frame member and the guide therein defining a plurality of spaced cooperating square apertures therethrough; e. first and second pins each square in cross section, the first pin being positionable in any one of the apertures in one leg of the telescopic frame member and cooperating aperture of the guide associated therewith, the second pin being positionable in any one of the apertures of the other leg of the telescopic frame member and cooperating aperture of the guide associated therewith; and f. means associated with the legs of the base to limit inward sliding of the telescopic frame member relative to the base by blocking the pins positioned in their respective apertures.

2. A shoring structure comprising: a. a base having a pair of generally parallel tubular legs; b. a telescopic frame member having a pair of generally parallel tubular legs slidable outside the legs of the base, with the legs of the base within the inner bores of the tubular legs of the telescopic frame member so that the telescopic frame member is slidable inwardly and outwardly of the base; each leg of the telescopic frame member having a plurality of spaced apertures therethrough; c. a pair of guides, one fixed within each leg of the telescopic frame member, and spaced from the inner bore of that leg, the guides being disposed within the inner bores of the legs of the base, and defining spaced apertures therethrough cooperating with the spaced apertures through the legs of the telescopic frame member; d. first and second pins, the first pin being positionable in any one of the apertures in one leg of the telescopic frame member and cooperating aperture of the guide associated therewith, the second pin being positionable in any one of the apertures of the other leg of the telescopic frame member and cooperating aperture of the guide associated therewith; and e. means associated with the legs of the base to limit the inward sliding of the telescopic frame member relative to the base by blocking the pins positioned in their respective apertures.

3. A shoring structure comprising: a. a base having a leg member which is elongated along an axis and defines a first bore; b. a frame having a leg member which is elongated and extends coaxially with said base leg member, said leg member of said frame comprising a guide member and a tubular member defining a second bore surrounding said guide member, said leg member of said base being received within said second bore and said guide member being received within said first bore in telescopic relation thereto so that said frame leg member is slidable along said base leg member toward and away from said base; c. one of said leg members having a square aperture extending therethrough normal to said axis, said aperture having one of its pairs of opposite sides normal to said axis; d. a pin having a square cross section positioned in said aperture with its sides congruent with the sides of said aperture and projecting therefrom; and e. flat surface means associated with the end of the other of said leg members in contact with a side of said pin to limit the sliding of said frame leg member toward said base.