US2649298A - Volute spring - Google Patents

Volute spring Download PDF

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Publication number
US2649298A
US2649298A US161706A US16170650A US2649298A US 2649298 A US2649298 A US 2649298A US 161706 A US161706 A US 161706A US 16170650 A US16170650 A US 16170650A US 2649298 A US2649298 A US 2649298A
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United States
Prior art keywords
spring
active
coil
coils
volute
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US161706A
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English (en)
Inventor
Cal W Wulff
Frank G Newman
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Holland Co
Original Assignee
Holland Co
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Publication date
Priority to BE524034D priority Critical patent/BE524034A/xx
Application filed by Holland Co filed Critical Holland Co
Priority to US161706A priority patent/US2649298A/en
Application granted granted Critical
Publication of US2649298A publication Critical patent/US2649298A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F3/00—Spring units consisting of several springs, e.g. for obtaining a desired spring characteristic
    • F16F3/02—Spring units consisting of several springs, e.g. for obtaining a desired spring characteristic with springs made of steel or of other material having low internal friction
    • F16F3/04—Spring units consisting of several springs, e.g. for obtaining a desired spring characteristic with springs made of steel or of other material having low internal friction composed only of wound springs
    • F16F3/06—Spring units consisting of several springs, e.g. for obtaining a desired spring characteristic with springs made of steel or of other material having low internal friction composed only of wound springs of which some are placed around others in such a way that they damp each other by mutual friction
    • 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
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F1/00—Springs
    • F16F1/02—Springs made of steel or other material having low internal friction; Wound, torsion, leaf, cup, ring or the like springs, the material of the spring not being relevant
    • F16F1/04—Wound springs
    • F16F1/08—Wound springs with turns lying in mainly conical surfaces, i.e. characterised by varying diameter
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49609—Spring making

Definitions

  • This invention relates to. volute. springs, either of the type designed Withbuilt-in absorption to carry live loads, or of the. type designed.' lto act as snubbers with other ⁇ parallelY mounted springs carrying major portion of the load.
  • the primary object of the invention is t'o, pro.- vide a spring of these types'. which has superior damping properties and. characteristics when compared with volute springs now in use, and which because of their. built-inabsorption characteristics are capableY of absorbing, vastlyY greater work energy over. their effective lifi. ⁇ cycle than prior art volute springs of comparable dimension andA material.
  • Figure l is a side elevational view partly section showing a volute snubber spring made in accordance with this invention, the spring being shownat its free height. after being. given av cold. set;
  • Figure 2 isa plan View ofthe. samek with the dead coilsl being indicatedby distinctive crosshatching;
  • Figure 3' is a side.. elevational View ofj the springl shownvin Figures 1. and' 2V but. shows, the. form of the coil as wound,A and before being given a coIdj set;
  • Figure 4 (subdividedl into Figures. 40t-v to 4e inclusive) shows the profile as coiledY slope ⁇ of the developed bar for various types of, volute, springs, as indicated by suitable legends;
  • Figure 5 is a graph showing, in. comparison with a conventional tight-woundl volute spring,l the load-deflection characteristics (bothon compression and release) of.' a volute. spring made in accordance withk this invention.
  • volute springs are not tooV well" known andthe fact is that in considering volute springv formulas there are, in addition to.- the primary torsional stress 'produced by a cen.- tral load, manysecondary. stresses which. arise out of the variation. ofthe twisting torquefrom.vr section to section, by iiexibility of. they dead. coils and by misalignment. of. the. springL seats.,
  • volute spring designs for use as load-carrying springsl have normally avoided' contact between adjacent .coils because experience demonstrated' that the contacting, surfaces were non--unifornny with the result that gougini occurred, producing excessive wear and ac celeratedv failure. ⁇
  • volute spring of substantially greater workeabsorbing. capacity by buildingl certain fricti'onal4 adsorption forces intothe spring and controllingl its characteristics: so that the frictional forces are ⁇ substantial', are evenly spread'over wide areasLwillnot he effec*- tively l'ost as the spring wears, and which pro*-y vi'de vol'utezspring characteristics never before at'- tained'.
  • our spring is a. non-har"- monic snubber spring in whichY energy absorption through friction is of greatest. importance.
  • negative lielixY angle is meant a7 deyei'oped bar whose proie before setting curves upwardly'from outer activev 'coil to innerA active coil;
  • the graphline lo is a straight line and for that, reason the. spring may besaid. to, have. a constant. helix angle.
  • volute springs 'using a positive helix angle such as shown by the graph line I4 in Figure 4c, and in this case the axial pitch indicated by the lines 15a, [5b and 15o decrease at some rate which does not produce uniform stress indicated by the graph line I6 the profile of a ⁇ developed bar as coiled, and in this case the pitch, indicated by the lines lla, Hb and Hc, is constant.
  • the inner active coil will be more severely stressed than the middle active coil, and this latter coil will in turn be more highly stressed than the outer active coil.
  • the latter pitch being defined as one that in wound to provide a reverse pitch, negative helix angle in the as coiled condition.
  • a spring is shown in Figure 3 and the vouter Vdead coil is indicated at 20, the inner dead coil at 2l, the outer active coil atw22', the middle active coil at 23 and the inner. active ,coil at 24.
  • the coil has reverse axial pitch, i. e., the inner active coil is more greatly pitched than the middle active coil 23, and this latter coil is more greatly pitched than the outer active coil 22.
  • volute springs constructedV Let us consider now a volute spring that is in accordance with this invention and made of C1085 spring steel may be coiled at about 1800 F. (which is well above the critical temperature for this particular material) and then quenched, after which the springs are tempered by reheating to a temperature of about 750 F., the Precise temperature being determined by the ultimate physical properties desired.
  • the spring is given a cold set, i. e., compressed to solid and then released and vibrated to nd its true free height, it will be found that the elastic transformation of the steel that has taken place on cold setting gives it a pitch somewhat as shown in Figure 1.
  • the springs, after coiling, and before being given their cold set are heat treated according to particular requirements, and one of the advantages of the reverse axial pitch is that it exposes more of the friction surface to the desired heat treatment before the spring is given its cold set, thereby improving the physical properties ofthe spring itself. Furthermore, the ex posure of greater areas of the inner and middle coils for heat treatment is fortuitous because surface and depth hardness are of extreme importance.
  • the particular axial pitch given to the several active coils is determined by the end characteristics desired but, generally speaking, the inner activev coil is designed Vso that when the spring is given its cold set it Will be stressed almost to maximum capacity of the material and the middle active coil will be stressed somewhat less with the outer active coilbeing stressed very lightly during the cold set.
  • the outer active coil together with the outer dead coil acts as a resilient casing for the middle and inner active coils during their deflection, and the constant or increasing pitch given tothe active coils, as coiled, tends, upon cold setting, to packthe inner active coil tightly intok the middle active coil, and the middle active coil tightly (although slightly less so) intoV the outer active coil, with the result that there is an inherent radial pressure exerted between the active coils which maintains them in tight frictional contact throughout the life of the spring, that is, each active coil is contained under positive radial compression within its adjacent outer coil.
  • Figure 5 shows a load deiiection curve, both on compression and release, for a spring made in accordance with our invention-this in comparison with a conventional tightwound volute spring of equi-valent dimension and material.
  • Figure 5 shows a load deiiection curve, both on compression and release, for a spring made in accordance with our invention-this in comparison with a conventional tightwound volute spring of equi-valent dimension and material.
  • the characteristic curve for the improvedY spring made in accordance with this invention is shown in full lines, whereas the characteristics of a conventional springr are indicated in dotted lines.
  • the area under a compression curve is a measure of the work vdone or energy expanded in deiecting the spring.
  • the area under the release curve represents the work expended by the spring in returning to its original free height against a resisting load.
  • the work expended by the spring in returning to its free height will be less than the work expended in compressing the spring. rihe difference in the compression and release work is the energy' or work absorbed by the spring.
  • the compression and release curves for a given spring are commonly called the hysteresis loop for that spring, and it is essential in a snubber springY to have the area between these two curves ofV the desired magnitude, taking into consideration the particular application of the snubber spring. This represents the work absorbed by the spring.V
  • the bar from which the spring is to be made is iirst scarfed to provide a blank such as shown on page 361 of Mechanical Springs by A. M".
  • Wahl, 19a-e' ed., and' the spring is then tightly wound about a substantially cylindrical mandrel provided with the usualv stripping taper.
  • the bar is heated well above critical temperature, say, to about D F. and tightly wound under exwith the'scarfedportion of the inner inactive coil normal to the axis of the mandrel.
  • the bar as it is wound about the mandrel it will have a constant free helix angle, but this angle may be changed by guiding the bar as it is wrapped around the mandrel, this being accomplished with a lead screw having the desired pitch or rate of pitch.
  • a lead screw In order to provide the ordinary positive helix angle, a lead screw is used which has increasing pitch so that the bar as it is Wrapped around the mandrel is extended along the length of the mandrel.
  • the lead screw is, in a sense, reversed because, in order to obtain a negative helix angle, it is necessary to restrain rather than augment the distance which the spring extends itself along the axis of the mandrel during coiling. All of this will be clearly understood by those skilled in the art.
  • outer active, middle active and inner ⁇ active coils should not be interpreted to mean that the outer active coil and the inner active coil must necessarily be a full 360 coil, because in some cases either of these two coils may be something less than 350 in extent.
  • a volute spring the combination of inactive outer and inner coils and at least three active intermediate coils, all tightly wound, the outer active coil being low-stressed, the middle active coil highly stressed vand the inner active coil still more highly stressed, whereby the outer active coil acts as a resilient casing to yieldably oppose unwrapping of the middle and inner active coils, said middle and inner active coils maintaining firm frictional contact with each other even after substantial wear due to the high stressing of said middle and inner active coils, and said spring being hot-wound with an increasing helix angle from outer active coil to inner active coil, and then cold set, whereby secondary stresses due to coning are attenuated.
  • a volute spring the combination of inactive outer and inner coils and at least three active intermediate coils, all tightly wound, the outer active coil being low-stressed, the middle activercoil highly stressed and the inner active coil still more highly stressed, whereby the outer active coil acts as a resilient casing to yieldably oppose unwrapping of the middle and inner active coils, said middle and inner active coils maintaining rm frictional contact with each other even after substantial wear due to the high stressing of said middle and inner active coils, and said spring being hot-wound with an increasing axial pitch from outer active coil to inner active coil and then cold set, whereby secondary stresses due to coning are attenuated.
  • a tightly wound volute spring comprising inactive outer and inner coils and at least three intermediate active coils, said spring after being tightly wound while hot and before cold setting being characterized by having its active coils provided with constant or increasing axial pitch from outer active coil to inner active coil, whereby upon compression of the spring the inner and middle active coils expand radially outwardly more rapidly than their adjacent enveloping coils to provide a continuous radialV pressure between said adjacent coils.
  • a tightly wound volute spring comprising inactive outer and inner coils and at least three intermediate active coils, said spring after being tightly Wound while hot and before cold setting beingl characterized by having its active coils provided with an increasing helix angle from outer active coil to inner active coil, whereby upon compression of the spring the inner and middle active coils expand radially outwardly more rapidly than their adjacent enveloping coils to provide a continuous radial pressure between said adjacent coils.
  • a volute snubber spring comprising inactive outer and inner coils and at least three active intermediate coils, including an active outer coil, an active middle coil, and an active inner coil, said active coils having overlapping, substantially cylindrical, working surfaces in rm, substantially uniform contact with each other and under intense inherent radial compression when the spring is at free height, whereby the spring has a relatively high energy absorption under light loads.
  • a volute snubber spring as set forth in claim 5 in which the spring in its as-coiled condition and before cold-set is characterized by an increasing helix angle whereby after cold setting the material distribution within the active coils is such that upon compression of the spring, the inner and middle active coils expand radially outwardly more rapidly than their adjacent enveloping coils to provide a continuous radial pressure between said adjacent coils as the spring is compressed.
  • a volute snubber spring 'as set forth in claim 5 in which said spring is hot-wound and then cold set, and in which the spring structure in its as-coiled condition before cold setting is characterized by a constant or increasing axial pitch from outer active coil to inner active coil.
  • a volute snubber spring as set forth in claim 5 in which said spring is hot-wound and then cold set, and in which the spring structure in its as-coiled condition before cold setting is characterized by an increasing helix angle from outer active coil to inner active coil.
  • a volute spring the combination of inactive outer and inner coils and at least three active intermediate coils, said spring being tight wound while hot with an increasing helix angle and then cold-set, whereby the outer active coil is low-stressed, the medium active coil highly stressed, and the inner lactive coil still more highly stressed, with the outer active coil acting as a resilient casing to yieldably oppose unwrapping of the middle and inner active coils, said spring being further characterized by relatively high inherent radial compression forces between the active coils when the spring is at free height.
  • a volute spring the combination of inactive outer and inner coils and at least three active intermediate coils, all tightly wound, the outer active coil being low-stressed, the middle active coil highly stressed and the inner active coil still more highly stressed, whereby the outer active coil acts as a resilient casing to yieldably oppose unwrapping of the middle and inner active Y coils, said middle and inner active coils maintaining rm frictional Contact with each other even after substantial wear due to the high stressing of said middle and inner active coils, and said spring being hot-wound with an increasing helix angle from outer active Coil to inner active Coil, and then cold set, said active coils after cold setting being under relatively high, continuous, radial compression.
  • a volute spring the combination of inactive outer and inner coils and at least three active intermediate coils, all tightly Wound, the outer active coil being low-stressed, the middle active coil highly stressed and the inner active coil still more highly stressed, whereby the outer active coil acts as a resilient casing to yieldably oppose unvvrapping of the middle and inner aetive coils, said middle and inner active Coils maintaining firm frictional Contact With each other even after substantial Wear due to the high stressing of said middle and inner active coils, and said spring being hot-Wound with an 19 increasing helix angle from outer active Coil to inner active coil, 4and then cold set, said spring being under relatively high radial compression zero load due to the radial expansion during cold setting of at least one of said active coils at a greater rate than its enveloping adiacent eoil.

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  • General Engineering & Computer Science (AREA)
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US161706A 1950-05-12 1950-05-12 Volute spring Expired - Lifetime US2649298A (en)

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BE524034D BE524034A (nl) 1950-05-12
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3253571A (en) * 1965-04-22 1966-05-31 Preformed Line Products Co Appliance for linear bodies
US3504228A (en) * 1967-07-31 1970-03-31 Champion Spark Plug Co Spark plug with an internal resistor
US3756162A (en) * 1971-03-05 1973-09-04 Holland Co Car body roll dampening spring bolster
US4936511A (en) * 1988-11-28 1990-06-26 Minnesota Mining And Manufacturing Company Spray gun with disposable liquid handling portion
US4971251A (en) * 1988-11-28 1990-11-20 Minnesota Mining And Manufacturing Company Spray gun with disposable liquid handling portion
US5878998A (en) * 1997-08-27 1999-03-09 Hsieh; Frank Conical spring
US20050269871A1 (en) * 2003-09-01 2005-12-08 Kiyoshi Saito Brake system
US20070089533A1 (en) * 2005-10-24 2007-04-26 The Boeing Company Compliant coupling force control system
US20150115702A1 (en) * 2013-10-29 2015-04-30 Bendix Commercial Vehicle Systems Llc Volute spring for a foot brake valve

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US433343A (en) * 1890-07-29 Window-screen
US2075815A (en) * 1934-09-29 1937-04-06 Harry A Knox Method of forming a volute spring
US2176719A (en) * 1938-08-03 1939-10-17 American Locomotive Co Method and machine for making springs
US2220857A (en) * 1939-11-24 1940-11-05 American Locomotive Co Volute spring and a method of making same
US2390937A (en) * 1940-12-10 1945-12-11 Holland Co Method of manufacturing volute springs

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US433343A (en) * 1890-07-29 Window-screen
US2075815A (en) * 1934-09-29 1937-04-06 Harry A Knox Method of forming a volute spring
US2176719A (en) * 1938-08-03 1939-10-17 American Locomotive Co Method and machine for making springs
US2220857A (en) * 1939-11-24 1940-11-05 American Locomotive Co Volute spring and a method of making same
US2390937A (en) * 1940-12-10 1945-12-11 Holland Co Method of manufacturing volute springs

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3253571A (en) * 1965-04-22 1966-05-31 Preformed Line Products Co Appliance for linear bodies
US3504228A (en) * 1967-07-31 1970-03-31 Champion Spark Plug Co Spark plug with an internal resistor
US3756162A (en) * 1971-03-05 1973-09-04 Holland Co Car body roll dampening spring bolster
US4936511A (en) * 1988-11-28 1990-06-26 Minnesota Mining And Manufacturing Company Spray gun with disposable liquid handling portion
US4971251A (en) * 1988-11-28 1990-11-20 Minnesota Mining And Manufacturing Company Spray gun with disposable liquid handling portion
US5878998A (en) * 1997-08-27 1999-03-09 Hsieh; Frank Conical spring
US20050269871A1 (en) * 2003-09-01 2005-12-08 Kiyoshi Saito Brake system
US20070089533A1 (en) * 2005-10-24 2007-04-26 The Boeing Company Compliant coupling force control system
US7469885B2 (en) * 2005-10-24 2008-12-30 The Boeing Company Compliant coupling force control system
US20150115702A1 (en) * 2013-10-29 2015-04-30 Bendix Commercial Vehicle Systems Llc Volute spring for a foot brake valve

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