US1138345A

US1138345A - Expansion-bolt.

Info

Publication number: US1138345A
Application number: US87396814A
Authority: US
Inventors: Lothar R Zifferer
Original assignee: Individual
Current assignee: Individual
Priority date: 1914-11-25
Filing date: 1914-11-25
Publication date: 1915-05-04
Anticipated expiration: 1932-05-04

Description

v l L. R. ZIFFERER.

- ExPA'NsloN BOLT. APPLIATION FILED NOV. 25, 1914.-

1,13s,3.45; Patented May 4,1915.

www u LohdrRZff-ergyfp ,Lorimn a. ZIFFERER, or new YORK, N. Y.

EXPANSION -BOLR specification of Letters Patent.

Patented May 4., i915,

Application filed November 25, 1914. Serial No. 873,968.

To all 'a0-fiom t may concern:

Ile' it Vknown that I, Lo'rHAn R. ZIFFERER, a citizen of the United States, residing at New York, in the county of New York andv State of New York, have invented certainv new and useful Improvements in Expansion- Bolts, of which the following is a specification. l

This invention relates to expansion'l bolts formed of a relatively hard .material,-'such as malleable iron, and is concerned with certain exterior and interior features of shield construction.

. My invention has for one of its principal l'objects lthe provision of elements Aupon the shield exterior. so formed, arranged, and

`sented for convenience as formed of two proportioned as to allow an easy insertion ofthe device into jits intendedaperture, to resist withdrawal from the aperture, and

prevent rotary movement within the aperture.

. The invention furtheriis concer-ned with.

the mechanical construction and arrangement ofthese exterior elements to the end that the forces of compression exerted upon the shield may best be withstood.

Other objects and uses will also appear from a detaileddescription of the invention as hereinafter set forth.

There are many'materials in which expansion bolts may be anchored. Brick, tile,l concrete, and masonry of all kinds are among the most common. Shields for expansion bolts have heretofore been designed to resist withdrawal from, and rotation within, apertures in materials such as those mentioned.

So far as I am aware, these ends have not been satisfactorily accomplished, due principally, to neglect of factors which are always present.

It is to provide an expansion bolt the structural elements of which are so arranged as to resist movement and pressure of every kind, that the present invention is designed.

In the drawing: lFigure 1 lis a view of an expansion bolt embodying my invention, shown partially inserted within an aperjture; Fig. 2 is a view similar to Fig, 1, .showing the device completely inserted'within an aperture;"Fig. 3 is an endview of a slightly modified lform of device' shown inj serted within an aperture; Fig. 4 is an enlarged transverse section taken on line 4-.4 of Fig. `2.

"'{In the drawing is shown a shieldv repre- -

complementary sections

6 and 7, held opera-l tively together yat their outer ends by means of clamps 8, engaging within notches 9.' The disposed transversely lof the shield axis, and

intended to be embedded within the material surrounding the hole when-expansion is produced. 4It is manifest-that such transverse elements serve primarily to resist longitudi pal movements ofthe shield within its aperure.

Each of the shield sections at its outer end is provided with a number of projections or longitudinal -ribs 11 of substantially the same elevation a's the transverse ribs 10. A single projecting fin 12 is arranged symmetrically with respect to the other ribs 1l, this being f greater' elevation, and prefer-- ably 'inclined as appearsbest in Figs. 1 and .2. The disposition of this fin is substantially midway'between the meeting faces of the shield sections. The arrangement shown -in Fig. 3 is the same as-in F ig, 2, except that the fin 12 is duplicated on the opposite side of the shield, the other elements remaining the same. e

.Installation of the present expansion bolt within an aperture of proper dimensions is readily effected up to the point where. the Further 'inser.

ribs 11 encounter the hole. tion is `possible only by forcibly advancing the shield, as by the use ofa hammer. lIt is manifest that complete insertion must result in one of two things: either (l) the outer end of the shield'must be distorted and' advances.

The use of a pluralityof longitudinal ribs, each intended -to cut a slight furrow intol an aperture has heretofore been suggested,

as I am aware, but this is not a practical construction, as experience has demonstrated ico that the numberv of furrows to be so cut mustl be multiplied so many times as to make such a furrow-cuttingv action practically Aimpossible. Alsol I have known of expansion shields, substantially cylindrical at the outer end,uexcept for the provision of a singleprojecting fin, which shields were found to be unsatisfactory because they would be collapsed, ci'ushed, or distorted when' driven into operative position within apertures. ln

be readily so cut, and to resist successfully the tendency to crush or collapse the shield sections at theirouter ends.

The purpose of the lribs 11,-it should be explained, is to present relatively sharp edges against the interior of the aperture which shall, by a frictional engagement, re sist turning of the shield when a bolt, screw, or lag screw is inserted to cause expansion. The projecting fin 12 enhances greatly the resistance against rotation of the shield, by being forcibly interlocked within the wall as distinguished from the rictional engagement of the ribs 11. It is apparent, of course, that'the pressure exerted on the outer end of the shield by the forcible entry of the fin into the anchoring body is distributed to each of the other ribs 11, so the pressure of these ribs against the inside of. the aperture is greatly increased. It appears best from Fig. l that .I have provided altogether eight longitudinal ribs,

' one of which is the lin 12. This number,

and the disposition of the same .inthe manner illustrated, I prefer to any other. This is due partly to considerations of expediency in manufacture, and also to the ability of such an arrangementof ribs to withstand stanti ally effectively the pressure resulting trom embedment of the fin 12 Within the wall. Between these ribs the panels or spaces are flattened to eliminate curvatures in construction. When, fromthe direction of this fin,

forces are exerted inwardly sutlicient to crush, collapse, or distort the outer end of the shield, the pressure is distributed over the outer end of each'shield half through the straight-line panels which act as braces, and thrust back against the aperture Walls at seven different points. The distances be tween such points of pressure thrust are so close, and the material so shaped to serve as bracing elements, that bending or buckling of the shield cannot take place--a fault hitherto common in the constructions i I have mentioned.

claim:

An expansion bolt shield having its outer end slightly less in diameter -than the remainder of the shield bo'dy, a projecting fin on the outer end of the shield extended above the `shield body, and other projections disposed parallel lwith the shield axis of subeven height with the shield body, all of the said projections being arranged not more than 45 degrees apart, substantially as described.

LOTHAR R. ZIFFERIZR. Witnesses:

P. FRANK SONNEK, H. E. CHAMPION.