Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS1056095 A
Publication typeGrant
Publication dateMar 18, 1913
Filing dateFeb 3, 1913
Priority dateFeb 3, 1913
Publication numberUS 1056095 A, US 1056095A, US-A-1056095, US1056095 A, US1056095A
InventorsCharles Groos
Original AssigneeCharles Groos
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1056095 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)




1,056,095 Patented Mar. 18, 1913.




Specification of Letters Patent.

Application filed September 20, 1911, Serial No. 650,304. Renewed February 3, 1913. Serial No. 746,036.

To all whom it may concern:

Be it known that 1, CHARLES GRoos, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have-invented new and useful Improvements in Screw-Drivers, of which the following is a specification.

My invention relates to improvements in screw drivers, and the object of the inventionis to provide a screw driver of such construction that a screw, also of special construction, may be screwed in merely by a torsional force applied to the screw driver, thus dispensing with the necessity of applying direct or longitudinal pressure thereto.

It is a matter of common experience that in the majority of cases, the greater part of the force exerted in screwing in a screw is expended in maintaining the screw driver in engagement with the screw. Unless pressure, and sometimes very great pressure, is applied to the screw driver, its operating end will slip out of the groove in the screw head, involving a loss of time in re-applying the screw driver to the screw. A further oio jection, and a very serious one, to the present forms of screw and screw driver is that,

owing to the difficulty, especially when screwing into hard material, of maintaining the operating end of the screw driver in engagement with the head of the screw, and the frequent violent disengagement of the one from the other, the surface of thematerial worked upon is scratched and marred by the points or edge of the screw driver when making such slips. By so constructing a screw driver and screw that torsional force applied to the screw driver tends to hold the screw driver to the screw the more securely the greater is the force applied, the necessity of direct pressure on the screw driver is eliminated, and the force necessary to be exerted is only that required to turn the screw in the material.

In the accompanying drawing, Figure 1 is an edge view of one form of my improved screw driver; Fig. 2 is a broken side view thereof; and Fig. 3 is a side view of a screw adapted for use with the screw driver shown in Figs. 1 and 2.

Referring to the drawing, 1 indicates my the respective edges of said side.

the operating terminal portion'of said screw driver, very near the end 2 thereof, there are formed two transverse grooves 3, commencing near the central longitudinal line of said side, and increasing in depth and width to In the head 4 of a screw 5 is formed a groove 6 which has overhanging beveled sides 7 When such a screw driver 1 is fitted to the screw 5, and torsional force is applied thereto, the left-hand grooves in the advancing and following sides of the screw driver respectively engage corresponding'portions of the upper edges of the sides 7 of the undercut groove 6 in the screw head. so that torimproved screw driver. Upon each side of sional force applied to the screw driver serves to cause the screw driver to cling more firmly to the screw head, and therefore no direct or longitudinal pressure need be applied to the screw driver to maintain it in engagement with the screw. In unscrewing the screw, the other grooves 3 come into operation and engage other portions of said edgesin like manner.

I claim 1. A screw driver formed near its operatving end and on each side thereof with a transverse groove commencing near the central longitudinal line of said side, the two grooves extending to opposite edges of the screw driver and increasing in depth to said edges.

2. A screw driver formed near its operating end and on each side thereof with oppositely extending transverse grooves oommencing near the central longitudinal line of said side and increasing in depth to the edges of said side.

3. A screw driver formed near its operating endwith a transverse groove commencing near the central longitudinal line of one side and increasing in depth to an edge of said side. 7

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2676510 *Sep 23, 1950Apr 27, 1954Nat Screw & Mfg CompanyScrew driver slot with driver wedging means
US2684094 *Jun 21, 1951Jul 20, 1954Lissy JohnNonslip screw driver and screwhead
US3815945 *Aug 31, 1972Jun 11, 1974Lamphere EDoor frame security plate
US4339971 *Jan 28, 1980Jul 20, 1982Zatorre Alfredo EFastener and driving tool
US4538486 *Nov 21, 1983Sep 3, 1985Jacques LutratNon-slip screw
US4977800 *Mar 21, 1990Dec 18, 1990Colvin David SScrewdriver blade construction
US5438895 *Apr 29, 1994Aug 8, 1995Bassell; MarvinFastener and driving tool
US5582548 *Jul 22, 1991Dec 10, 1996Czegledi; ImreMethod of manufacture of anti-slip fastener
US5722838 *Feb 14, 1994Mar 3, 1998Czegledi; ImreFastener system and method of manufacture thereof
US6526851 *Jun 14, 2002Mar 4, 2003Richard D. FuerleUndercut screw and matching bit
US7425112 *Nov 3, 2004Sep 16, 2008Nowak Jr Edmund ATamper resistant screw
US20030125745 *Oct 8, 2002Jul 3, 2003Bio One Tech Inc.Bone-fixing device
US20050169729 *Nov 3, 2004Aug 4, 2005Nowak Edmund A.Jr.Tamper resistant screw
US20080034930 *Aug 8, 2006Feb 14, 2008Landes Ruediger HNon slip screw
US20090165604 *May 22, 2008Jul 2, 2009Macor Richard JEngaging portion of a screwdriver
US20090165605 *Sep 12, 2008Jul 2, 2009Macor Richard JScrewdriver with torque-enhancing sidewall edges
DE1272847B *May 30, 1960Jul 11, 1968Ver Zur Foerderung Von ForschuSchraubendreher
WO1990007402A1 *Dec 27, 1989Jul 12, 1990Colvin David SScrewdriver blade construction
U.S. Classification81/436, 411/406, 411/919
Cooperative ClassificationY10S411/919, B25B15/007