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Publication numberUS1261916 A
Publication typeGrant
Publication dateApr 9, 1918
Filing dateFeb 27, 1913
Priority dateFeb 27, 1913
Publication numberUS 1261916 A, US 1261916A, US-A-1261916, US1261916 A, US1261916A
InventorsWalter Scott Forbes
Original AssigneeWalter Scott Forbes
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Non-removable screw.
US 1261916 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)


PatentedApr. 9,1918.

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. 7h??? 3251 Howe Witmaooeoz 9g m WALTER SCOTT'FORBEKOF NEW YORK, N. Y.

NoN-Rumovnnnn SCREW.

Specification of Letters Patent.

Patented Apr. 9, 1918.

Application filed February 27, 1913. lSerial No. 751,141.

To all w wmz't may Concern Be it known that I, WALTER S. FORBES, a citizen of the United States, and resident of the borough of'Richmond, 'county of Richmond, city and State of New York, have vinvented certain new and useful Improvements in Non-Removable Screws, of which the following is a specification.

I have found that it is sometimes desirable to set an ordinary wood or machine screw in such a manner that it cannot be readily withdrawn or so that it cannot be withdrawn at all by any ordinary or easily accessible means.

I have found that where a hinge or lock must be placed upon the exterior of a door, gate, or cover and where it is desirable or necessary because of the surrounding conditions to attach said hinge or lock by means of hand or machine driven screws, that could such screws be so constructed that they could not be withdrawn additionalsecurity would result and constructions would be possible that under ordinary conditions are impossible or impractical.

This device is intended kto operate in the manner as above set forth and provides a screw fulfilling these necessary requirements. The means by which this screw is inserted are to be removed when the screw is in place. The construction and operation that accomplishes these very desirable results will be set forth as the specification progresses.

The following is what I consider the best means of carrying out this invention. K

The accompanying drawings form a part of this specification in which Figure l shows my completed device and is in elevation.

Fig. 2 shows a machine screw having certain of my improvements.

Fig. 3 shows a section of the line 3-3'in Fig. l and viewed in the direction of the arrows.

Fig. 4 shows in plana head as it will be constructed for particular heavy duty and large screws.

Fig. 5 shows in plan the head as it will be constructed for ordinary'service.

Fig. 6 shows in plan a hinge or plate with the screw inserted.

Fig. 7 shows a modification in the shape of the screw.

Similar reference numerals indicate like parts in all the figures'where they appear.

The body f an ordinary screw is shown at l, this body is provided with ordinary screw-threads and requires no further description as this construction is not changed or modified in myy device. At 2, I have shown a tapered head of familiar outline.

This head is similar in shape to the ordinary tapered head but the slot usually provided in the upper plane surface is omitted.

Arranged upon the head and spaced definite distances apart I provide a plurality of lugs 3 and 4. These lugs may be of any desirable length or width but for convenience it is my intention that between them they will present projections having just sufficient strength and area to allow the screw to be turned reliably into place.

Between the head and the body of the screw I produce a shank and formed integral with this shank I arrange a plurality of projections 6. I produce these projec-V tions in such a manner that their Hat face shall not retard or make difficult the turning of the screw during the insertion thereof. I may produce but one or two of these projections or I may produce a plurality as shown.

Vhen the screw is used under eXtreme conditions or `when a particularly large screw is to be used I may provide more of the projections 3 and 4 as shown in Fig. 4 and indicated by 7 and 8.

My improved screw may be used in a very ordinary manner the point being started, the blade of the screw driver is placed between the projections 3 and 4, and the screw turned in toits full extent. When all is tight and secure the blade of the screw driver is removed and then with the assistance of a small saw or chisel the projections 3 and 4, useful in setting the screw are removed.

The screw-head will upon the removel of the lugs or projections 3 and 4 present a flat and plain surface, flush with the hinge or plate through which it passes. f

From Fig. 7 it will be seen that these projections may be formed on a. screw of any general shape or construction.

It is my intention that the projections 6 formed in the shank of the screw shall act as teeth oiering no or little resistance while screw is being inserted, but cutting well into the surrounding wood or metal when an attempt is made to withdraw the screw. These teeth or projections may however be omit-

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2457180 *Mar 24, 1945Dec 28, 1948Lee Rushing HerschelRail track fastening
US2749770 *Sep 18, 1952Jun 12, 1956Entpr Railway Equipment CoOperating head for rotating shaft of hopper closure
US2942323 *Mar 10, 1959Jun 28, 1960Moser Paper CompanyEmbalming stopper
US3134291 *Oct 9, 1961May 26, 1964South Chester CorpNon-removable screw
US3460428 *Mar 7, 1968Aug 12, 1969Nat Screw & Mfg Co TheThreaded fastener with torque limiting drive portions
US3812757 *Jan 27, 1972May 28, 1974Textron IncThreaded fastener with torque control head
US4109691 *Dec 21, 1977Aug 29, 1978Wilson Floyd LeroyCombination torque release screw and screw driver
US7066062Oct 22, 2004Jun 27, 2006Flesher Robert WTorque-setting, tamper-resistant fastener and method and tool for use with same
US7441483May 9, 2007Oct 28, 2008Flesher Robert WTamper-resistant fastener and method and tool for use with same
US8690504 *Dec 8, 2011Apr 8, 2014Phoenix Contact Development and Manufacturing, Inc.Torque-limited and removable fastener for one-time use
US8840349 *Apr 7, 2008Sep 23, 2014Fisher Controls International, LlcMulti-tool adjusting screw
US20040228703 *May 12, 2004Nov 18, 2004Simon SuchOne way threaded security fastener and installation tool
US20050141986 *Oct 22, 2004Jun 30, 2005Flesher Robert W.Tamper-resistant fastener and method and tool for use with same
US20060228190 *Jun 13, 2006Oct 12, 2006Flesher Robert WTamper-resistant fastener and method and tool for use with same
US20080256754 *Apr 7, 2008Oct 23, 2008Jason Scott MeviusMulti-tool adjusting screw
US20130149065 *Dec 8, 2011Jun 13, 2013John Phillip Huss, Jr.Torque-Limited and Removable Fastener for One-Time Use
U.S. Classification411/402, 411/910, 411/919
Cooperative ClassificationY10S411/919, Y10S411/91, F16B23/00