Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Threaded fastener locked to a discreet structure – Member preassembled with substructure at through-passage or...
Reexamination Certificate
1998-06-18
2001-05-29
Trettel, Michael F. (Department: 3628)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Threaded fastener locked to a discreet structure
Member preassembled with substructure at through-passage or...
C411S353000, C411S352000, C411S970000
Reexamination Certificate
active
06238155
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to torque screws of the type generally used to attach an object to a panel or frame wherein it is desired to limit the torque the screw may place on either the object or frame such that potential damage caused by over tightening the screw is eliminated.
Various requirements in manufacturing and assembly of components have dictated the need for a screw fastener that cannot be over tightened such that damage to panels or other object to which the fastener is attached does not occur. Various torque limiting screws exist in the prior art, including U.S. Pat. No. 5,120,168 to Padula, and U.S. Pat. No. 4,109,691 to Wilson, each of which is a “single use only” screw which provides tamper resistance, but here, once the screw is installed, it cannot easily be unscrewed. U.S. Pat. No. 4,472,098 to Kiefer is an invention for a torque limiting nut that uses an elastomeric material to engage a threaded screw shaft. None of these patents disclose a torque screw that allows reuse an indefinite number of times and allows the screw to be unscrewed in a normal manner.
Additionally, none of these torque screws is of a captive screw style.
Finally, it would be advantageous to have an audible signal indicating that the torque screw has reached its predetermined torque limit. It is not believed that any screws of the present type have this audible feature.
SUMMARY OF THE INVENTION
The present invention relates to a torque screws in general. The present invention provides a torquelimiting arrangement in which the screw may be tightened down to a particular torque. Once that torque value is reached, the knob of the screw rotates without significant further tightening down of the threads of the screw. The action is accomplished by means of a “C” shaped spring which acts as a driver to transmit torque from the knob to a flange on the screw in the tightening mode, but that deflects inwardly, thus disengaging the driving action when the knob is rotated clockwise at a point when a predetermined torque is reached.
The torque screw is hand tightenable to tighten, for example, a first panel to a second panel, but once the predetermined torque is reached, the torque screw “slips” and allows for substantially no more significant torque to be supplied to the screw threads.
The torque screw comprises a screw having a head and a threaded shaft, a knob having a central longitudinal axis coaxial with the screw, and a one-directional ratchet means disposed between the knob and the screw that engages to allow the screw to be disengaged in a counter-clockwise direction using the knob, and engages when the knob is rotated in a clockwise direction to a predetermined torque value. Then, the knob slips generally freely, such that further clockwise rotation causes the knob to slip relative to the knob. When the knob is rotated in a counterclockwise direction, the ratchet locks and causes the screw to rotate counterclockwise at all times during the counterclockwise rotation of the knob.
An alternate embodiment has the above mechanism, but has a ferrule that is attachable to a panel, where the knob is captivated on the panel. The captivation means of the knob on the ferrule allows for limited axial movement of the knob with respect to the ferrule and full rotational movement of the knob with respect to the ferrule, but limited by the ratchet means.
A driver recess is optionally placed on the top surface of the knob to aid in rotating the screw.
It is therefore an object of the present invention to provide a new and improved torque screw.
It is another object of the present invention to provide a new and improved torque screw that is reliable and simple to manufacture.
It is another object of the present invention to provide a new and improved torque screw that spins generally freely relative to the screw shaft once a predetermined torque is reached.
It is another object of the present invention to provide a new and improved torque screw that is in the form of a single article without the need for a separate torque wrench or driver.
It is a still further object of the present invention to provide a new and improved torque screw that provides a desired torque by hand or with a standard screwdriver or similar tool.
It is a further object of the present invention to provide a new and improved torque screw that provides audible indication of when the maximum torque allowed by the screw has been reached.
It is a still further object of the present invention to provide a new and improved torque screw that provides for the torque screw to be captivated on a panel such that loose items of hardware are eliminated.
Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: D. 283591 (1986-04-01), Swanstrom
patent: D. 357176 (1995-04-01), Ernest et al.
patent: D. 388316 (1997-12-01), McDonough et al.
patent: 748078 (1903-12-01), Kaisling
patent: 1166345 (1915-12-01), Gates
patent: 1188420 (1916-06-01), Eadie
patent: 1664820 (1928-04-01), Hughes
patent: 2006359 (1935-07-01), Lackner
patent: 2151255 (1939-03-01), Witchger
patent: 2331322 (1943-10-01), Heinick
patent: 2470927 (1949-05-01), Hale, Jr.
patent: 2503189 (1950-04-01), Biba, Jr.
patent: 2553236 (1951-05-01), Bratfisch
patent: 2773574 (1956-12-01), Able
patent: 2831520 (1958-04-01), Clarke
patent: 2967557 (1961-01-01), Tait et al.
patent: 2987811 (1961-06-01), Acres
patent: 3033260 (1962-05-01), Snow
patent: 3052942 (1962-09-01), Mulvaney
patent: 3059736 (1962-10-01), Boyd
patent: 3126935 (1964-03-01), Tuozzo
patent: 3137336 (1964-06-01), Wing
patent: 3180389 (1965-04-01), Frank
patent: 3195600 (1965-07-01), Middleton, Jr.
patent: 3204680 (1965-09-01), Barry
patent: 3209807 (1965-10-01), Ryner
patent: 3244212 (1966-04-01), Barry
patent: 3245450 (1966-04-01), Sauter
patent: 3250559 (1966-05-01), Sommerfeld
patent: 3263728 (1966-08-01), Lynch
patent: 3279302 (1966-10-01), Modrey
patent: 3343581 (1967-09-01), Martin et al.
patent: 3346032 (1967-10-01), Gulistan
patent: 3385341 (1968-05-01), Garstkiewicz
patent: 3437119 (1969-04-01), Dey
patent: 3465803 (1969-09-01), Ernest et al.
patent: 3564563 (1971-02-01), Trotter et al.
patent: 3571904 (1971-03-01), Gulistan
patent: 3718950 (1973-03-01), Engstrom
patent: 3865007 (1975-02-01), Stanback
patent: 3866878 (1975-02-01), Yamamoto
patent: 3912411 (1975-10-01), Moffat
patent: 3958308 (1976-05-01), Gooding
patent: 4007516 (1977-02-01), Coules
patent: 4047266 (1977-09-01), Bisbing
patent: 4107960 (1978-08-01), Neiman
patent: 4109691 (1978-08-01), Wilson
patent: 4199216 (1980-04-01), Gryetko
patent: 4387497 (1983-06-01), Gulistan
patent: 4398322 (1983-08-01), Ewen
patent: 4418590 (1983-12-01), Dubiel et al.
patent: 4472098 (1984-09-01), Kiefer
patent: 4492500 (1985-01-01), Ewing
patent: 4602903 (1986-07-01), Wilburn
patent: 4692075 (1987-09-01), Metz
patent: 4915557 (1990-04-01), Stafford
patent: 4952107 (1990-08-01), Dupree
patent: 4964773 (1990-10-01), Schmidt
patent: 5042880 (1991-08-01), Garuti et al.
patent: 5094579 (1992-03-01), Johnson
patent: 5120168 (1992-06-01), Padula
patent: 5209018 (1993-05-01), Heinrich
patent: 5336028 (1994-08-01), Yamomoto
patent: 5374268 (1994-12-01), Morris
patent: 5382124 (1995-01-01), Frattarola
patent: 5388139 (1995-02-01), Swanstrom
patent: 5429467 (1995-07-01), Gugle et al.
patent: 5537262 (1996-07-01), Aoki et al.
patent: 5544992 (1996-08-01), Ciobanu et al.
patent: 5611654 (1997-03-01), Frattarola et al.
patent: 5642972 (1997-07-01), Ellis et al.
patent: 558456 (1958-06-01), None
patent: 1339942 (1962-11-01), None
patent: 2 268 977 (1975-04-01), None
patent: 2 578 009 (1986-02-01), None
patent: 2 636 384 (1988-09-01), None
patent: 625345 (1949-06-01), None
patent: 626013 (1949-09-01), None
patent: 825877 (1959-12-01), None
patent: 1579730 (1980-11-01), None
Southco, Inc., Southco Latches and Access Hardware Handbook 45 NA, C1-C44, Pennsylvania, 1995.
Penn Engineering & Manufacturing Corp., “Fasteners For Use In Or With PC Boards”
Aukzemas Thomas V.
Dickerson Harry L.
Ellis Thomas J.
Ji Lianli
Conley Fredrick
Paul & Paul
Southco Inc.
Trettel Michael F.
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