US2873829A

US2873829A - Umbrella anchor

Info

Publication number: US2873829A
Application number: US496548A
Authority: US
Inventors: Wiegmann Dietrich
Original assignee: PAUL TOBELER
Current assignee: PAUL TOBELER
Priority date: 1955-03-24
Filing date: 1955-03-24
Publication date: 1959-02-17
Anticipated expiration: 1976-02-17

Description

Feb. 17, 1959 D. WIEGMANN 2,373,829

UMBRELLA ANCHOR Filed March 24, 1955 5 Sheets5heet 2 4 INVENTOR.

DIE O WEIG ANN ATTORNEY Feb. 17, 1959 Fild March 24, 1955 D. WIEGMANN 2,873,829

UMBRELLA ANCHOR 3 Sheets-Sheet 3 MMIIIIHI INVENTOR.

. DlETRI H WEIGMANN ATTORNEY UMBRELLA ANCHOR Dietrich Wiegmaun, Bremen, Germany, assignor of onehalf to Paul Tobeler, doing business as Trans-Oceanic, Los Angeles, Calif. J

Application Marc 24, 1955, Serial No. 496,548

' "6 Claims. cuss-92 This invention relates generally tosubterranean anchors for supporting walls, piles and the like, and more specifically has to do with umbrella anchors having armsadapted to be expanded underground to provide tension or bearing supports for corresponding loads. The invention especially concerns itself with a novel type anchor adapted to be introduced undergroundin a casing and subsequently manipulated from a remote point after removalof the casing to accomplish expansion of the an-.

chor arms into the surrounding subterranean material.

' In previous devices ofthis -so'rt,the anchor arms have,

in certain cases been connected to supporting structure in such a way that expansion of the arms was sought to be accomplished by displacing the support structure with cement or other material introduced in the hole, the weight of the cement being depended upon to expand the arms outward into the soil. In other cases the protective casing. was left in the ground and the anchor arms were forced out throughslits in thecasing by interengagement between the arms and shoulders on the casings when the supporting structure was displaced. 7 Y I Disadvantages inherent in suchdevices have to do with uncertainty of spreading o f the anchor arms, and the dif-1 ficulty of causing penetration ofthe arms into the soil, Similarly, in those devices wherein the arms .are exposed to.lthe soil during driving of the casing, the adherence and compaction of :dirt to the armscon'tribjute to the uncertainty and difficulty of securing desired'expansion of the anchor assembly.

TTher'present invention obviates these, problems, assuringv positive expansion of the anchor assembly, to provide desired footing, and furthermore contemplates the provision :of readily ,expansible anchors capable. of ,withstanding-tension or compression loading. Furthermore, by virtue of the essential simplicity of the device, it is readily; possible to construct additional anchorages for" supporting wallsorthe likein'front ofor adjacent to existing construction facilities which are ,already'we'ighed' down, sogas toIend' a dditiQnal support to such facilities or to. provideadditiohal anchorages for extensionof' such facilities.

In accordance with the invention, thereisiprovided an I umbrella anchor assembly including anchor arms carried at the lower endof a shank, which is movable axially'insidea protective casing and manipulatablef from thesu'rface above theupper end,of the casing, The arms are positioned circumferentially:around the shank and pivotally connected to a pair vof collars in such away that after the casing is removed, onecollar maybe .forcefully moved toward-the other, causing the arms to expand outward and, away fr'ofn' the shank for engagement with and penetration into the adjacent soil toviform the desired footing., ,To this end,- one .collaris fixed on the end-of the shank andthe other collar .is spaced therefrom and slidably mounted on the shank for manipulation-fromthe surface by means of a sleeve or tube surrounding the shank. Forcible displacement of the sleeve against the movable collar and toward the fixed collar causes posiposition;

'5 5 ofFig. 3;

,Fig. 6 is a view similar to Fig. l showing'a modified- Referring to Figs l'through 5, the expansible anchor sectiongincludin g a 'longit udinally curved base 21 and a'central'web 22, a section of which is divided into laterally spaced portions 23 resulting in a double-webbed:

. collars to prevent over-expansion of the arms of the anchor. Each of the arms carries lateral surfaces 'which face and curve away from the shank, so that when the arms are spread they will move outwardly to penetrate the earth along a path of least resistance, thereby minimizing the power required to accomphsh anchor expansion. The arms are desirably formed in T-section'to facilitate direct penetration into the soil, and also to provide strength and rigidity.

Additional features and objects of the invention, as

, Well as the details of an illustrative embodiment thereof,

will be more fully understood from the following detailed description of the accompanying drawings, in which:

Fig. l is a sectional view of the protective casing illustrating the collapsed condition of the umbrella anchor therein; 7

Fig. 2 is anelevation illustrating the umbrella anchor in opened or spread position after removal of the casing; I

Fig. 3 is an end view of the umbrella anchor in spread Fig. 4 is an end view, partly in section, showing the position of the umbrella anchor in'collapsed condition within the casing;

Fig. 5 is an enlarged sectional view taken on line form of the apparatus; and i Fig. is a view similar to Fig. 2 showing the spread position ofthe modified anchoring apparatus.

assembly 10 is mounted on an end portion of anchor shank 11, which is extensible through the cyhndrical protective casing. 12having an open end13 facilitating withdrawal of jthe casing from the'anchor-f'assembly 10 throughilheopen end. ,Anchor shank ll'carries' a pair of

collars

14 and 15,"the former being retained in fixed position onthe' threa ded end of the anchor shank betweennuts 16, .and'thelatter being slidable on shank 1 1 towardQand away frorn collar 14. 'A sleeve 17 is interposed between thetwo collars arid mounted on shank 11 to limit the movement of collar toward collar 14 for purposesto be explained' A series of brackets'ls arefixed on the 'side of collar 14 facing collar 15 for supporting the ends of anchor arms 19 from hinge connections such as pins 20, the

anchor arms being positioned symmetrically around shank 11 andextending inthe direction of shank 11 whenin collapsed"con dition as shown in- Fig. 1; Each of the arms '19 is formed to have a'T-shape in'bross T construction as shown in Fig. 3. The base is slotted beneath the. elongated opening 24 formed between web'.

portions 23 to receive a push rod or lever 25; one endof which is hingedbetween web portions 23 and the other end of which' is "hinged *toslidabl'e collar 15, the hinge connections being suitably formed by'pins 26 and 27. J-

The"'base"21of each'bf -the arms comprises a spadelike surface, which is convex toward shank 11 and which extends from bracket 18 toward the free end of arm 19 Clos- I 3 with an ever widening lateral dimension, as better shown in Flg. 3. The widened outer end 28 of each of the bases is sharpened at its forward edge to facilitate penetration into the earth, as will be explained.

In operation, the anchor arm assembly mounted on anchor shank 11 is introduced into the drill casing 12, which extends into a formation beneath the earth surface. When in collapsed condition, the anchor arm assembly slides freely through the casing, since the arms 19 are mounted by brackets 18 in such a way that the arms pivot inwardly out of engagement with the inner walls of the casing, forming a clearance therebetween. After the assembly has been introduced to the bottom of the casing, the latter is removed a short distance, as by pulling it upward, so that the anchor arm assembly passes through the end portion 13 of the casing and becomes exposed to the earth at the bottom of the drilled hole. The assembly is then spread open in umbrella-like fashion by forcing collar 15 toward collar 14, as by means of sleeve 29. The latter slides over anchor shank 11 into direct engagement with collar 15 and is caused to force the latter collar toward collar 14 to open the anchor arm assembly, suitable retaining forces being exerted in an opposite direction on anchor shank 11.

Closing movement of the two collars urges push-levers toward fixed collar 14 and causes the hinge connection at 26 to force the anchor arms outward and away from the anchor shank, the arms pivoting about pins 20. Resistance to penetration by arms 19 may be overcome by exerting sufiicient equal and opposite forces on sleeve 29 and anchor shank 11, as by means of a hydraulic press operable at the surface of the earth. Anchor arms 19 are thereby spread open to approach a 90 angle with respect to shank 11, as shown in Fig. 2, over-spreading of the arms being prevented by engagement of collar 15 with the end of sleeve 17. It will be apparent that relative displacement between portions of sleeve 29 and shank 11 at the earth surface serves to inform the operator of the extent and condition of arm spreading.

Once the anchor has been brought into desired spread condition, push-sleeve 29 is removed and casing 12 is pulled upward from the earth, the hollow space left by the'casing then being filled with sand or other material, along with added water, to eliminate any hollow spaces in the earth surrounding the anchor. Alternatively, concrete may be pulled into the opening to fill the voids'left by removal of the casing.

Forming the bases 21 of the anchor arms to have a convex shape enables their penetration into the formation surrounding the anchor with minimum resistance, since enlarging of the penetration openings caused by their displacement into the earth is thereby kept to a minimum. During spreading of the arms into the earth, the anchor collar 14 is slightly shifted inthe direction of pulling upon anchor shank 11; however, after spreading is completed, further displacement of the anchor is not possible since the bases 21 of the arms flatly engage a large portion of the earth immediately surrounding the anchor, resistance to displacement of which is transmitted to movable collar 15 abutting sleeve 17 and preventing movement thereof. For this reason, the present device serves very effectively as a tension-resisting anchor.

In. the construction shown in Figs. 6 and 7, the position of anchor arms 19 and push levers'25 is reversed, the arms being hinged to movable collar 15 and the push levers hinged to the fixed collar 14. In addition, the anchor shank 11 comprises end sections 11a and 11b threaded together in end-to-end relation, and the threaded connection 30 between sections 11a and 11b may be rotated to disconnect it from section 11a for removal from the drilled hole.

anchor shank spread away therefrom, adapting the anchor assembly to be used as a support capable of withstanding compression loading such as may be exerted by pilings, columns and the'like. Removal of the casing 12 and concreting of the empty hole left thereby remain the same as previously described. In addition, it is possible to use a pull cable permanently fixed to section 11a instead of utilizing anchor shank 11b.

I claim:

1. The combination, comprising an elongated tubular casing adapted to be inserted into a hole drilled underground, an expansible anchor assembly within the casing and adapted to be expanded after endwise removal of the casing so as to expose the anchor assembly to the surrounding underground formation, said assembly including an elongated anchor rod axially movable within the casing to carry said assembly underground and manipulatable from the surfaceof the earth, a plurality of elongated anchor arms circularly spaced about the end portion of said rod and extending substantially longitudinally therealong in collapsed condition accommodating free axial movement of the entire assembly within the casing, fixed and movable supports carried in axially spaced relation on the rod near the end thereof, and means including links and pivots relatively loosely interconnecting one end and the intermediate portion of each arm respectively to said supports, each of said arms being substantially longer, than the diameter of said casing and including an elongated relatively narrow blade extending in a longitudinally curved plane that is everywhere convex toward the anchor rod, each blade diverging from a location adjacent the rod to the free end of the blade adjacent the inner wall of the casing, the free ends of the blades being sharpened and having transversely curved relatively widened extent, each of said arms also including web means integral with said blade and extending longitudinall'y at the blade outer side facing said casing, said pivots being connected to said links, Webs and one of said supports and said blades containing longitudinally elongated openings through which said links project, and means for displacing saidmovable support relatively toward said fixed support for causing the links to swing the arms outwardly about their pivoted ends and away from said rod.

2. The invention as defined in claim 1 in which said supports comprise collars one of which is attached to the rod near the end thereof and the other of which is axially slidable on the rod.

3-. The invention as defined in claim 2 in which said one end of each arm is pivotally connected to the collar attached to said rod.

4. The invention as defined in claim 2 in which said one end of each arm is pivotally connected to the collar slidable' on the rod.

5. The invention as defined in claim 2' including a stop sleeve on the rod between the collars to stop relative closing together movement of the collars when said arms have been swung outward to extend substantially nor? 1 mal to the rod,and in which said means for displacmg the movable collar comprises an elongated sleeve 'on the rod at the side of the movable collar opposite said stop webs and being pivotally connected thereto.

References Cited in the file of this patent UNITED STATES PATENTS