Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
  • F16G13/00—Chains
  • F16G13/02—Driving-chains
  • F16G13/04—Toothed chains

Definitions

• This invention relates to silent chain having laterally positioned links that form sets. These link sets are arranged in a series throughout the length of the chain.
• Silent chain has been used to drive vehicles having either four wheel drive or front wheel drive.
• Such chain is formed by links that have two teeth for contacting a sprocket.
• each set of links making contact with sprocket teeth have identical working contact surfaces.
• These link sets are arranged consecutively in a series that extends throughout the length of the chain.
• Known chains have utilized various types of working contact surfaces, such as inside face, interior surface or crotch contact and outside face, exterior surface or flank contact. However, these working contact surfaces that are defined by the link teeth are the same for all sets of links in the chain.
• the present invention reduces noise and provides a longer wear life for an automotive chain of the silent type.
• Such chains create noise when periodic vibrations develop during operation of the chain.
• noise results from both chain vibration and chain contact with adjacent structure, such as a drive housing.
• a silent chain having articulated link sets with teeth adapted for operative engagement with sprocket teeth.
• Each link in a set has two teeth that define at least one surface that is adapted to come into intimate physical working contact with sprocket teeth.
• a plurality of link sets that have similar working contact surfaces are arranged consecutively in series throughout the length of the chain.
• At least one link set, having working contact surfaces that differ from those of the plurality of link sets, is arranged in series with the plurality of link sets to vary the type of tooth contact between the chain and the sprocket teeth.
• an automotive drive chain has similar links positioned laterally of each other in link sets. These link sets are arranged in series throughout the length of the chain. Pins extend transversely of the links through openings therein. The links that are positioned laterally of each other extend between adjacent pins forming discrete link sets within the chain. Alternate link sets within the series of link sets have outer guide links secured near the outer ends of the pins. The link sets which include the outer guide links have less links than the link sets which do not include outer guide links. The outer guide links and links within the same link set are in strencth balance with the link sets which include a greater number of similar links.
• the links within the link sets are arranged in a weave pattern to achieve a balance between the link sets for optimum tensile strength, fatigue strength and wear life of the chain.
• BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a broken perspective view of a silent chain drive embodying the present invention.
• Figure 2 is a plan view of the silent chain shown in Figure 1, with parts broken away to show the cylindrical pins .
• Figure 3 is a section in elevation of a drive sprocket portion having trained thereabout a length of the silent chain shown in Figure 1.
• Figure 4 is a side elevation view of a flank contact link superimposed upon a crotch contact link to illustrate the difference between the two types of links.
• a drive 10 has an end less silent chain 12 that is trained about a drive sprocket 14 and a driven sprocket 16. These sprockets have outwardly extending teeth 18, while the chain has inwardly extending teeth 20 that mesh with the sprocket teeth.
• Link sets P 1 have outer guides 24 secured near the outer ends of the pins.
• Individual links 26 are spaced laterally inwardly from the outer guides, and four groups of double links 26 are spaced therebetween.
• Link sets P 2 include a middle group of three links 28, one individual link 28 spaced outwardly on each side of the middle group, and two groups of double links 28 spaced outwardly from each individual link. While Figure 2 represents but one weave pattern, various lateral lacing arrangements can be utilized to achieve a balance between the guided link sets P 1 and the non-guided link sets P 2 .
• each link set is desired to achieve optimum tensile strength, fatigue strength and wear life of the silent chain.
• Such balance enables each link set to have about the same tensile strength, provides a higher concentration of link material at the outer portions of the link sets where fatigue failure generally occurs, and minimizes unit bearing stresses that affect wear rates.
• the solid cylindrical pins 22 are received in aligned openings 30 and 32 of both the links 26 and 28. These pins are slightly smaller in diameter than the link openings, but the pins are slightly larger in diameter than openings in the outer guides 24.
• the links are pivotal with respect to the pins, while the outer guides are pressed on the pins.
• the pins may be peened at their outer ends to assure that no outer guide is accidentally stripped from a pin.
• the pins pivotally connect adjacent link sets P 1 and P 2 .
• the outer guides hold the links on the pins and engage the sides of the sprocket teeth 18 to maintain the chain 12 on the sprockets 14 and 16. These outer guides also carry a proportional amount of the tensile stress within the chain.
• the guided link set P 1 has ten links 26 plus the two outer guides 24.
• the pivotal link set P 2 includes thirteen links 28.
• the two outer guides 24 provide strength equal to three links 28 because the depth of the outer guide is not reduced by a crotch section as in the links 26 and 28.
• the link sets P 1 and P 2 have substantially the same tensile strength.
• a length of the silent chain 12 is trained about a portion of the drive sprocket 14.
• This chain includes link sets P 1 and P 2 that are arranged alternately in series throughout the length of the chain.
• the sets P 1 include outer guides 24 and links 26, while the sets P 2 include links 28.
• These links may be similar to each other or they may be differentiated from each other by the type of contact that they are designed for making with the sprocket teeth 18.
• Those links designed for crotch contact are further designated by the letter c, while the link designated for flank contact is further designated by the letter f.
• Figure 4 shows a flank contact link 28f superimposed upon a crotch contact link 28c. Both of these links have a straight edge 34 at one side.
• each link Near one end of each link is a circular opening 30, and a circular opening 32 is located near the other end of the link.
• An imaginary center line L may be drawn between the two openings 30 and 32.
• Both of these links have two longitudinally spaced teeth 20 projecting on the link side opposite from the straight edge.
• the teeth of link 28f have outside, exterior or flank contact surfaces 36, while link 28c has such surfaces 37.
• the flank contact link has inside, interior or crotch contact surfaces 38, while the crotch contact link has such surfaces 39.
• Both links have an uninterrupted span of metal between the openings 30 and 32 on the tooth side of the imaginary center line L drawn between the open- ings.
• an automotive drive of the silent chain type can be quieted by introducing into a series of sets of links throughout the length of the chain, at least one link set having working contact surfaces that differ from those of other link sets in the series.
• link sets having different types of tooth contact there is variation in the manner in which such links contact, pivot and slide into meshing engagement with the sprocket teeth.
• periodic vibrations are broken up by varying the type of tooth contact that link sets within a series make with sprocket teeth.
• the links within the link sets are arranged in a weave pattern to achieve a balance between the link sets for optimum tensile strength, fatigue strength and wear life of the chain.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)
• Gears, Cams (AREA)
• Chain Conveyers (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22682069

Family Applications (1)

Country Status (7)

Cited By (6)

Citations (13)

• 1981
  • 1981-04-24 JP JP56501913A patent/JPS57501619A/ja active Pending
  • 1981-04-24 WO PCT/US1981/000540 patent/WO1982000866A1/en not_active Application Discontinuation
  • 1981-04-24 EP EP19810901430 patent/EP0059715A4/en not_active Withdrawn
  • 1981-04-24 BR BR8108788A patent/BR8108788A/pt unknown
  • 1981-09-08 IT IT23837/81A patent/IT1138206B/it active
  • 1981-09-09 ES ES1981268664U patent/ES268664Y/es not_active Expired
  • 1981-09-10 BE BE0/205931A patent/BE890308A/fr not_active IP Right Cessation

Patent Citations (13)

Non-Patent Citations (1)

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