US1005630A - Screw-anchor. - Google Patents

Description

S. H. FLEMIN".

SCREW ANCHOR.

APPLICATION FILED AUG 3, 1910.

Patented Oct. 10, 1911.

Toguli whom it may concern:

J'esidcnt of (hit-ago. county of (look. and

' formed of a coiled strip of soft metal. such wound upon a cylindrical forming rod;

' preferably project heyond the exterior sur- "UNITED STATES PA1*ENT Omen;

Application filed August 3,

lie it known that T. Srnrnnx ll. FLEM- ixo. a citizen of the United States. and a- State of l llitmls. have invented certain new and useful Improvements in Screw-Anchors. of which the following is a full, clear. and exact description.

The invention relates to anchors for securing screws within sockets formed in lHitlt work. cement. stone or t'hc'likc. and seeks to provide a simple and etl'ective (01b struction which can he economically made in large quantities. i a

The invention consists in the features of improvement hereinafter set forth. illustrated in the preferretlform in the. accompanying drawings" and more. part.icularl pointed out in the appended claims.

In the dr.-nvings. Figure l is a view in elevation of the improved screw anc hor. Fig. 2 a cross section thereof on the line 2-2 of Fig. 1. Fig. 3 is a ltmgitudinal section on the line 33 of Fig. 2. Fig. 4 is a view partially in elevation and partiallyin section of a modified form. Fig. 5 is a longitudinal sectional view of the anchor shown in operative position for holding a screw within its socket. Fig. 6 is a section on an enlarged scale on the line 6G of Fig. 5.

i The improved anchor comprises a sleeve as lead 0' an alloy of lead and tin or the like. The soft metal strip (1- is preferal'tly of rectangular cross section and is coiled or The cylindrical coil or sleeve thus formed can be readily and economically manufactured andthen cut into pieces or lengths to form the separate screw anchors.

The coils of the anchor sleeves preferably abut against one another (see Figs. 1, 2, 3 and 4) and longitudinally extended stay pieces I) are provided for sustaining the coils in proper relative position. These stay pieces are formed of hrass or like metal and are provided with inwardly ii-ejecting teeth 0 which are forced into the coils of the soft metal strip a, as indicated in l igs. l. 2 and These strips extend longitudinally upon the exterior of the anchor sleeve and face, as most-clearly shown in Fig. 2. Two of these strips are shown in the form illus- Specification of Letters Patent.

I rammed Oct. 1oQtfsii1. 191 0. set-taint). 575 367. .-f

tratcd. but more may he used aif nec or (lt.\'lI'tll)l(-' a The thickness of the wall ofthe sleeve or am-hor.--tltatis to say. the thicln'tcss'of the" soft metal strip from which the sleeve" or anchor is formed. should preferably ll( slight]; greater than the depth ,nf;;the thread of thescrew for which illt tttlt' lltil' is designed, it being understoml. ofleourse." t hat-the improved anchor'is niade in different sizes in aecordahce with the different sizes of screws. The interior diameter. of the sleeve or-anchor is prefei'ahly slightly. less than the shank or barrel of anemia for which it. is designed. Thefcoil is. wound .in the directionofthe thread of tlie st -rt. w

which is,. of coursesusuallyin righthand direction. In using thefnnproved anchor, a.sui.tal le hole or socket is formed in the h rick, -s t:onc.

cement or the like. and the anchor. placed therein with its inner end in engagement with the bottom of the hole or soeketg: The sharp end a of the stripat the. inner. end of the sleeve orzanchor catches on the-hob. tom of the socket; and,- as, the screw is threaded into the outer end ofthe sleevetlfc coils of the latter tend to unwind a-nd*thus expandinto hindingcontact with -the=,-wall of the hole or socket. even though the-latter is somewhat. largerthan the "anchor 'slecve. As the screw is driven .into the sleeve. it expands the latter-and its threads readily cut into the soft metal body ofJ-the coils; At the same time, the stay pieces 7) are driven into the sleeve, so that thev tend to rupture the latter along longit-ut'linal lines. as indicated in Fig. (3. and thus 't-ierm'it the further expansion of the soft metal body .-.f the sleeve or coiled strip into-lli'n'ding contact with the walls of the hole td therein the socket. w

The coils of the strip ((Wliittliftiiht the sleeve or anchor audthc teeth 0 of the stay pieces I) need have no particular relation to the. threads of the screw." T hose threads emhed themselves in the soft metal body of by firmly secure the anchor and screw,withvthe sleeve and? interlock in an irregular fashion with the teeth 1 of the stay pieces. The. stay pieces I) having the teeth c should too he formedof metal which is considerably tougher than thesoft metal strip a. The latter. as stated, is formed of lead or lead alloy. or the like. The stay pieces are prefreadily driven into the hole or. socket formed to receive the same. As theserew is driven in it expands the soft metal body, as described, and the shank or barrel of the screw will bear upon the ends of the teeth 0 position.

and force the stay pieces b into firmbind ing contact with the walls of the hole or, socket to further aid in holding the anchor screw in position. The threads of the screw -will' not be broken by contacting with the teeth 0, but the latter will be bent or defiected by the threads. Moreover, the ir regular interlocking of the threads and teeth will further aid in holding the screw in By forming the sleeve of a coiled-strip of soft metal the coils are separately expansi ble, so that they will readily conform to the opening for the'screw in spite of irregularities therein. The coils will thus be expanded into firm binding contact with all portions of the wall of the screw opening, even though this 0 ening may not be uniform throughout.

.urthermore, inasmuch asthe coilslare formed of a softmetal stri they need; 0t and preferably do not con orm to beiiigcut in the coils as'the screw is threaded into the sleeve, Furthermore, inasmuch asthe sleeve formed of a number of coils is readily expansible, the bore of the sleeve can be quite small, as compared to the shank of the screw with which-1t is used; without increasing the difiicultypf threading the screw into position. For this. reason the v coiled anchor can not only be readily forced 1nto snugbinding contact with the wallsof the screw opening, but will also snugly engage the shank and tlireads of the screw.

While the cylindrical form illustrated in Figs. 1, 3 and 5 is deemed preferable on account of economy in manufacture, the anchor may be'made in conical form, as shown in Fig. 4. It is also obvious that the particular details set forth maybe varied without departure from the essentials of the invention, as defined in the claims.

I claim as my invention p 1. A screw anchor comprising a cylindrical, expansible sleeve form diameter formed of a'=coi1ed, soft metal.

strip, the coils of said sleevebeingadafited j to be separately expanded snug binding contact with the wall of 'the'ppening for't he screw and to be indented by the threads of.

the screw, substantially as described.

2. A. screw anchor comprising a 'cylins, '1

'drical, expansible sleeve of substantially 'an form diameter throughout and havin internal diameter less than that of the s ank of the screw' for which itis designed, said sleeve being formed of a .coile'dsoft metal strip of substantially rectangular-cross-section, the coils'of said strip being in contact and adapted 'tobe expanded and indented by the threads of the screw, substantially as described. p

3. A screw anchorcomprising a cylindrical, expansibl'e' sleeve formed of a coiled, soft'metal strip anda strengthening stay for the sleeve extending lengthwise thereof.

4. A screw anchor comprising an expansi ble sleeve formed of a coiled strip of soft metal and stay pieces extending lengthwise substantially as described. the; reads ofthe screw, the female :thread 6. A screw anchor comprising an expansible sleeve formed of a coiled "strip of soft metal and longitudinally extending stay pieces having inwardly projecting teeth indenting the coils, substantially as described.

7. A screw anchor comprising a cylindrical, expanslble sleeve formed of a CQllBd, soft metal strip of rectangular section and stay .pieces extending longitudinally upon pieces of brass having inwardly projecting teeth indenting the coils, substantially as described.

- STEPHEN H. FLEMING.

Witnesses ELEANOR H. HAGENOW, KATHARINE GERLACH.

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