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Publication numberUS3136170 A
Publication typeGrant
Publication dateJun 9, 1964
Filing dateDec 26, 1962
Priority dateDec 26, 1962
Publication numberUS 3136170 A, US 3136170A, US-A-3136170, US3136170 A, US3136170A
InventorsMurray James J
Original AssigneeMurray James J
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Automatic tensioner
US 3136170 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

June 9, 1964 J. J. MURRAY AUTOMATIC TENSIONER Filed Dec. 26, 1962 INVENTOR. JAMES J MU RRAY ATTORNEY United States Patent lice 3,136,170 AUTOMATIC TENSIONER James J. Murray, 14011 Oakland Ave, Detroit 3, Mich. Filed Dec. 26, 1962, Ser. No. 247,091 4 Claims. (Cl. 74-242.11)

This invention relates to power transmission and particularly to the transmission of power by chain or belt driven mechanisms.

An object of the invention is to provide a device which will automatically maintain tension on a chain or belt drive.

Another object of the invention is to provide a device of the character indicated which is particularly suitable for use on power drives which have both forward and reverse action.

A further object of the invention is to provide a device of the character indicated, which is constructed and arranged so that it will automatically maintain tension on a fixed-center drive, whether it is operating in a forward or reverse direction.

Another object of the invention is to provide a chain or belt tensioner which consists of a minimum number of parts, is economical to manufacture, and is easy to install on new or old equipment without special tools.

Another object of the invention is to provide a device of the character indicated which is constructed and arranged so that it swings from side to side to automatically accomplish the slack take up, when the drive changes from forward to reverse.

Another object of the invention is to provide a device of the character indicated, which is constructed and arranged so that the necessity of down time for making adjustments is entirely obviated.

Another object of the invention is to provide a device of the character indicated, which is constructed and arranged to automatically take up the slack and to dampen the vibration in a forward and reverse chain driven ma chine.

Another object of the invention is to provide a device of the character indicated, which is constructed with a novel spring biased arm, which is positioned and arranged so that it swings through an arc sufiicient to automatically take up the slack on both the forward and reverse sides of a chain drive, whereby to eliminate any tendency of the slack in the chain to damage the equipment by breaking off sprocket teeth, or jamming the drive by back lash, or by jumping off the sprockets.

The foregoing and other objects and advantages of the invention will become more apparent as the description proceeds, reference being made from time to time to the accompanying drawings forming part of the within disclosure, in which drawings:

FIG. 1 is a plan view, with parts broken away, of a device embodying the invention.

FIG. 2 is a side elevational of the device shown in;

- FIG. 1, with parts broken away.

FIG. 3 is a section taken substantially on the line 3-3 of FIG. 2.

FIG. 4 is a diagrammatic view of the device shown in FIG. 1, combined with a forward and reverse drive mechanism.

Referring now more particularly to the drawings, it will be understood that in the embodiment herein disclosed, the reference character 7 indicates a base, or mounting plate, having apertures 8 for receiving bolts (not shown) by which the device may be secured to a machine, which is motivated, as shown in FIG. 4, by a forward and reverse chain drive.

The device is preferably mounted so that the arm 9 3,136,170 Patented June 9, 1964 may swing approximately 60 to either side of the positiOn shown in FIG. 1, ment may be as much as on either side.

The arm 9 is bored to receive the pivot shaft 10 which is press fitted or otherwise secured in a bore formed in the base 7.. A suitable bearing element 12 is positioned between the arm 9 and the shaft 10, so that the arm may freely pivot on the shaft. An idler which may be a sprocket as shown at 13 or a pulley or the like, which 18 pivoted for rotation on a pivot shaft 14, which passes through another bore 15 formed in the arm 9. The shaft 14 is secured by a nut 16 and is provided with a bearing member 17, so that the idler sprocket 13 may rotate freely thereon.

The arm 9 is spring loaded as follows: A stiff coil spring 18 is mounted around, as shown in FIGS. 2 and 3, the pivot shaft 10 and has end extensions 19 and 20 which respectively engage the opposite sides of a pair of pins 21 and 22. The pin 21 is an anchor pin and is secured to the base 7 and the pin 22 is a spring actuating pin and is secured to the arm 9 and extends through an opening in the top cover plate 23. The cover plate 23 is in contact with a dust cover 24, which encircles the spring 18 and the shaft 10. The cover plate 23 has a central opening to receive the pivot shaft 10 and rotates with the arm 9 by means of the pin 22. The assembly is held together by the nut 25 which engages a reduced threaded extension 10A of the shaft 10. Washers 26 and 27 complete the assembly.

As shown in FIG. 4, the device is mounted so that the idler sprocket 13 contacts the chain 28, which engages the driven sprocket 29 and the drive sprocket 30, which is rotated in forward and reverse directions by a suitable motor (not shown). The solid lines show the chain and tension arm when in forward direction and the broken lines, show their positions and relation when in reverse.

When the arm 9 is moved to the left (FIG. 1) the actuating pin 22 will move the spring extension 19 to the left while the extension 20 is held by the anchor pin 21. This places tension on the spring 18 in one direction. When the arm 9 is moved to the right (FIG. 1) the actuating pin 22 will move the extension 20 to the right while the extension 19 is being held by the anchor pin 21. This places tension on the spring 18 in the opposite direction. When the arm 9 is in the position shown in FIG. 1, the spring 18 is balanced and the arm is at rest. As soon as the idler sprocket 13 at the end of the arm 9 is brought into engagement with the chain 28 (FIG. 4) and the chain 28 is moved, the arm 9 will swing in the direction of the movement of the chain causing tension to be built up in the spring as described above. On the reverse of the chain tension will build up on the other side of the spring. The spring tension so built up, will automatically take the slack out of the chain in forward or reverse motions.

It is believed that the operation of the device is obvious from the foregoing description.

Having described my invention, what I claim and desire to secure by Letters Patent is:

l. A device of the character described, comprising a base plate, a pivot shaft secured to said base, an arm pivotally supported on said shaft, an idler on the free end of said arm, an anchor pin secured to said base plate, a second pin secured to said arm, and movable therewith, a coil spring surrounding said shaft and having its respective ends positioned on opposite sides of said anchor pin and said second pin and arranged so that upon a pivotal movement of said arm and said second pin in either direction on said shaft, tension is built up in said spring.

2. The structure of claim 1 in which said anchor pin on said base and the said pin on said arm when normally at although in extreme cases the move 3 rest are in alignment with the longitudinal axis of said pivotable arm.

3. The structure of claim 1 in which there is a rotatable cover plate spaced from said base plate and a dust cover surrounding said pivot shaft and said spring, and positioned between said base plate and said cover plate.

4. The structure of claim 1, in which there is rotatable cover plate spaced from said base plate and a dust cover surrounding said pivot shaft and said spring, and positioned between said base plate and said cover plate, there being a hole in said cover plate in which is received the said pin secured to said arm, and a second hole in said cover plate for receiving said pivot shaft whereby to permit said cover plate to rotate with said arm about said pivot shaft.

' References Cited in the file of this patent UNITED STATES PATENTS Bernhard Nov. 30, 1954

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1832958 *Feb 13, 1928Nov 24, 1931Andrew BachleCam shaft drive mechanism
US1982299 *Oct 7, 1931Nov 27, 1934Laval Separator Co DeBelt-tightener
US2139397 *Sep 8, 1936Dec 6, 1938Hill Clarke Machinery CoMotor driven headstock for machine tools
US2695528 *Aug 10, 1951Nov 30, 1954Bernhard OttoTractor
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3394730 *Jun 22, 1965Jul 30, 1968Robert A. ShermanHose reeling device
US3483763 *Dec 7, 1967Dec 16, 1969Gilson Brothers CoPower take-off for tractor engine
US3817113 *Jan 5, 1972Jun 18, 1974Sulzer AgChain drive with idler wheel tensioning means biased by elongated pads
US4285676 *Dec 17, 1979Aug 25, 1981Dyneer CorporationMechanical belt tensioner construction
US4392840 *Jan 12, 1981Jul 12, 1983Dyneer CorporationBelt tensioner
US4472162 *Apr 16, 1982Sep 18, 1984Dyneer CorporationBelt tensioner
US4504252 *Jul 27, 1984Mar 12, 1985Nissan Motor Company, LimitedBelt tensioner
US4557709 *May 3, 1982Dec 10, 1985I Corp.Belt tensioner system
US4957471 *Jul 24, 1989Sep 18, 1990St John Richard CAdjustable locked center and dynamic tensioner
US4962633 *Sep 28, 1989Oct 16, 1990Nouibra GmbhTangential belt drive for a spinning or twisting machine and method of operating same
US5131889 *Oct 22, 1990Jul 21, 1992Ford Motor CompanyAutomotive engine accessory drive tensioner
US5421788 *Nov 26, 1993Jun 6, 1995Ford Motor CompanyPulley and bearing assembly for internal combustion engine front end accessory drive
US5439420 *Apr 4, 1994Aug 8, 1995Ford Motor CompanyAccessory drive system for an automotive engine
US5531648 *May 5, 1995Jul 2, 1996Ford Motor CompanyAccessory drive system for an automotive engine
US5752891 *Mar 20, 1995May 19, 1998Ford Global Technologies, Inc.Electronically controlled accessory drive system for the automotive engine
US7360624Apr 26, 2005Apr 22, 2008Jtekt CorporationElectric power steering apparatus
US7367908 *Jan 10, 2004May 6, 2008Muhr Und Bender KgBelt tensioning device
US7413052Mar 15, 2007Aug 19, 2008Jtekt CorporationElectric power steering apparatus
US7490696 *Mar 15, 2007Feb 17, 2009Jtekt CorporationElectric power steering apparatus
US7824286Mar 28, 2005Nov 2, 2010York Industries, Inc.Device for placing a looped belt under tension
US20040171448 *Jan 10, 2004Sep 2, 2004Muhr Und Bender KgBelt tensioning device
US20050189162 *Apr 26, 2005Sep 1, 2005Koyo Seiko Co. Ltd.Electric power steering apparatus
US20060217223 *Mar 28, 2005Sep 28, 2006York Industries, Inc.Device for placing a looped belt under tension
US20070158130 *Mar 15, 2007Jul 12, 2007Takehiro SaruwatariElectric power steering apparatus
US20070187169 *Mar 15, 2007Aug 16, 2007Hiroto SasakiElectric power steering apparatus
DE3225411A1 *Jul 7, 1982Feb 3, 1983Litens Automotive IncRiemenspannvorrichtung
DE3546901C2 *Apr 4, 1985Feb 27, 1997Dyneer CorpEndless belt tensioner
EP0072134A1 *Jul 23, 1982Feb 16, 1983Eaton CorporationDrive tensioning device
Classifications
U.S. Classification474/135
International ClassificationF16H7/12, F16H7/08
Cooperative ClassificationF16H2007/081, F16H7/1281
European ClassificationF16H7/12N4