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US3596682A - Friction letoff control - Google Patents

Friction letoff control Download PDF

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Publication number
US3596682A
US3596682A US777306A US3596682DA US3596682A US 3596682 A US3596682 A US 3596682A US 777306 A US777306 A US 777306A US 3596682D A US3596682D A US 3596682DA US 3596682 A US3596682 A US 3596682A
Authority
US
United States
Prior art keywords
control device
brake
rod
lever
sensing rod
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
US777306A
Other languages
English (en)
Inventor
John H Nydam
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Draper Corp
Boeing North American Inc
Original Assignee
North American Rockwell Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by North American Rockwell Corp filed Critical North American Rockwell Corp
Application granted granted Critical
Publication of US3596682A publication Critical patent/US3596682A/en
Assigned to DRAPER CORPORATION, reassignment DRAPER CORPORATION, CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE APRIL 1,1982 Assignors: DELTA ACQUISITION CORPORATION,
Assigned to DELTA ACQUISTION CORPORATION reassignment DELTA ACQUISTION CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ROCKWELL INTERNATIONAL CORPORATION
Assigned to CITICORP INDUSTRIAL CREDIT INC. reassignment CITICORP INDUSTRIAL CREDIT INC. SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DRAPER CORPORATION F/K/A DELTA ACQUISITION CORPORATION
Assigned to STANCHART BUSINESS CREDIT, A CORP. OF CA. reassignment STANCHART BUSINESS CREDIT, A CORP. OF CA. SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DRAPER CORPORATION
Assigned to DRAPER CORPORATION, A CORP. OF GEORGIA reassignment DRAPER CORPORATION, A CORP. OF GEORGIA RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: CITICORP INDUSTRIAL CREDIT, INC.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D03—WEAVING
    • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
    • D03D49/00—Details or constructional features not specially adapted for looms of a particular type
    • D03D49/04—Control of the tension in warp or cloth
    • D03D49/06—Warp let-off mechanisms
    • D03D49/08—Warp beam brakes

Definitions

  • this invention pertains to improved means for sensing a decreasing radius of the material and its resulting rotating speed requirements and for providing compensating reductions in the braking force to provide near-constant tension throughout an entire beam.
  • This invention provides a sensing device which follows and is pivoted by the web of yarns or other materials as they are unwound from a beam by tension applied by a takeup.
  • a sensing wand as shown in the drawing is supported by the warp yarns at a position between the yarn beam and a fixed roller.
  • the wand might rest upon the upper surface, however, with thread or yarn it could be inserted as shown.
  • alternate groups of yarns running over and under the wand it is both supported and urged downwardly by the web.
  • the wand will follow the mean angle of declination taken by the sheet of yarn as the diameter upon the beam decreases without any further urging by springs or otherwise.
  • FIG. 1 is a diagrammatic view in side elevation of the invention in relative position to known loom parts
  • FIG. 2 is a front elevation of a portion of FIG. 1 as viewed from the left-hand side;
  • FIG. 3 is a partial plan view ofFIG. 1.
  • FIG. 1 a letofi is shown in diagrammatic form as arranged for a weaving loom, however, the invention might be applied to machinery for unwinding other flat continuous material such as cloth or paper.
  • a yarn beam 20, with only one of two beam heads 21 shown, is fully wound with a plurality of warp yarns 22.
  • the warp yarns 22 are drawn over a roller 23 rotatable on a fixed shaft 24 which also pivotally supports a bellcrank lever 25.
  • the lever 25 supports a whiproll 26 over which the warp yarns 22 are drawn with considerable tension by a takeup mechanism (not shown).
  • a straight lever 27 pivoted near its center which has at one end a rigid connecting rod 28 pivotally fastened.
  • Connecting rod 28 is also pivotally connected to one end of a sensing rod 29 which should have a polished surface and a generally round cross section.
  • Another connecting rod 30 extends pivotally between the sensing rod 29 and the fixed shaft 24.
  • the sensing rod 29 When used for letting ofi warp yarn, the sensing rod 29 may be inserted into the warp so that alternate groups of ends pass above and beneaththe horizontally extended rod as seen in FIG. 3. In this manner the sensing rod 29 is maintained in mean alignment with the warp as its angle to the horizontal changes in unwinding the beam 20 from full to empty. This angle is illustrated in FIG. 1 where the warp yarns 22 are numbered 22 as the beam is nearly exhausted. The tension of the warp yarns 22 will cause the sensing rod 29 to pivot in an are about the fixed shaft 24 and cause the connecting rod 28 to pivot the lever 27 to the dotted line position illustrated in FIG. 1. The sensing rod 29 is completely dependent upon the warp yarns 22 for movement and is sensitive to the slightest change in the letofi' angle followed by the yarn.
  • the sensing rod may extend into the warp yarns a short distance as shown or may extend further or fully across the warp. It is believed that having the rod inserted into a portion of the warp yarns will be sufficient to efiect accurate let off in most instances.
  • a rod 31 is fastened for movement in a substantially horizontal plane when the lever 27 is pivoted.
  • the rod 31 is encircled by a compression spring 32 having one of its ends restricted in position by an adjusting nut 33.
  • the opposing end of rod 31 is loosely inserted through a hole in a brake lever 34 so that the spring 32 will bear against the brake lever 34 to a varying degree at all times.
  • the brake lever 34 may be used in conjunction with a number of types of friction brakes suitable for application to a warp beam.
  • the brake used is a caliper type having a rotatable disc 35 in direct connection as by gearing (not shown) with the warp beam head 21.
  • the disc 35 is positioned to rotate between a fluid actuated brake 36 wherein opposing brake shoes may be compressed against the disc with controlled pressure.
  • Tubing 37 connects the brake 36 with a master-cylinder assembly 38 upon which the brake lever 34 is pivotally supported.
  • the brake lever 34 is pivoted on the cylinder assembly 38 so that the greatest pressure or braking force is exerted when the lever 27 is in the solid line position of FIG. 1.
  • the sensing rod 29 will gradually pivot downwardly as the warp diameter decreases until the dotted line positions of FIG. 1 are reached. As this downward movement takes place, a corresponding decrease in pressure is exerted upon the brake mechanism, which thus permits an increase in rotational speed to the yarn beam.
  • the rate of the spring 32 determines the let off of warp yarn from full to empty beam as evidenced by the pivotal distance of the lever 27. Adjustment in the yarn tension at the start of a full beam through variation in the brake pressure is made by turning the adjusting nut 33 on the threaded portion of rod 31.
  • This invention provides a highly sensitive and efficient mechanism for controlling rate of warp let off, which is completely automatic throughout the full to empty beam range.
  • a friction letoff control device for maintaining tension upon a sheet of continuous material defined by a plurality of warp yarns being drawn from a rotatable beam which comprises a. a brake mechanism for applying frictional restraint upon said beam,
  • a sensing rod projecting into said material so that groups of warp yarns extend alternately beneath and above said sensing rod whereby said rod is supported and adapted to be influenced by the material suspended between said beam and said fixed member
  • said sensing rod being supported by and angularly movable with the material extending from said beam
  • the frictional letofi control device defined in claim 1 further comprising means for maintaining tension upon said sheet of continuous material.
  • control device as set forth in claim 1, which further includes a reciprocating whiproll carried intermediate its ends by said fixed member, and wherein said linkage means is pivotally supported by one end of said whiproll lever.
  • said linkage means includes a. a pivotable lever supported by one end of said whiproll lever,
  • a brake-inducing rod pivotally connected with said pivotable lever and in active association with said brake mechanism.
  • linkage means further includes a spring adjustably positioned upon said brake-inducing rod and adapted to bear compressively against said brake mechanism.
  • said brake mechanism includes a caliper-type disc brake in a controlling relationship with the rotatable beam, and a pressureforming master cylinder having fluid connection with said disc brake.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Looms (AREA)
  • Warping, Beaming, Or Leasing (AREA)
  • Tension Adjustment In Filamentary Materials (AREA)
US777306A 1968-11-20 1968-11-20 Friction letoff control Expired - Lifetime US3596682A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US77730668A 1968-11-20 1968-11-20

Publications (1)

Publication Number Publication Date
US3596682A true US3596682A (en) 1971-08-03

Family

ID=25109888

Family Applications (1)

Application Number Title Priority Date Filing Date
US777306A Expired - Lifetime US3596682A (en) 1968-11-20 1968-11-20 Friction letoff control

Country Status (7)

Country Link
US (1) US3596682A (de)
JP (1) JPS4824107B1 (de)
BE (1) BE741939A (de)
CH (1) CH509219A (de)
DE (1) DE1958075A1 (de)
FR (1) FR2023672A1 (de)
GB (1) GB1275606A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5430918A (en) * 1994-03-29 1995-07-11 Cocker; John Warper delivery system having constant delivery angle
US20130221054A1 (en) * 2012-02-24 2013-08-29 Ricoh Company, Ltd. Sheet feeder and image forming apparatus including same

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US631430A (en) * 1896-10-17 1899-08-22 Charles F Perham Let-off mechanism for looms.
US2472548A (en) * 1945-02-24 1949-06-07 Wagner Electric Corp Automatic tensioning device for reels
DE931493C (de) * 1951-02-27 1955-08-11 Herbert Wirth Kettenfaedenfuehrung an Flachkettenwirkmaschinen
FR1292845A (fr) * 1961-06-26 1962-05-04 Régulateur de chaîne pour métier à tisser
US3464644A (en) * 1967-05-12 1969-09-02 Rolpa Sarl Device for winding off flexible material

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US631430A (en) * 1896-10-17 1899-08-22 Charles F Perham Let-off mechanism for looms.
US2472548A (en) * 1945-02-24 1949-06-07 Wagner Electric Corp Automatic tensioning device for reels
DE931493C (de) * 1951-02-27 1955-08-11 Herbert Wirth Kettenfaedenfuehrung an Flachkettenwirkmaschinen
FR1292845A (fr) * 1961-06-26 1962-05-04 Régulateur de chaîne pour métier à tisser
US3464644A (en) * 1967-05-12 1969-09-02 Rolpa Sarl Device for winding off flexible material

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5430918A (en) * 1994-03-29 1995-07-11 Cocker; John Warper delivery system having constant delivery angle
US20130221054A1 (en) * 2012-02-24 2013-08-29 Ricoh Company, Ltd. Sheet feeder and image forming apparatus including same
US9457596B2 (en) * 2012-02-24 2016-10-04 Ricoh Company, Ltd. Sheet feeder and image forming apparatus including same

Also Published As

Publication number Publication date
CH509219A (de) 1971-06-30
FR2023672A1 (de) 1970-08-21
BE741939A (de) 1970-05-04
JPS4824107B1 (de) 1973-07-18
DE1958075A1 (de) 1970-07-02
GB1275606A (en) 1972-05-24

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Legal Events

Date Code Title Description
AS Assignment

Owner name: DRAPER CORPORATION,

Free format text: CHANGE OF NAME;ASSIGNOR:DELTA ACQUISITION CORPORATION,;REEL/FRAME:004097/0735

Effective date: 19820920

Owner name: DELTA ACQUISTION CORPORATION; HORNADAY RD., GREENS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:ROCKWELL INTERNATIONAL CORPORATION;REEL/FRAME:004113/0020

Effective date: 19820321

AS Assignment

Owner name: CITICORP INDUSTRIAL CREDIT INC., A CORP. OF DE

Free format text: SECURITY INTEREST;ASSIGNOR:DRAPER CORPORATION A CORP. OF GA F/K/A DELTA ACQUISITION CORPORATION;REEL/FRAME:004070/0533

Effective date: 19821021

AS Assignment

Owner name: STANCHART BUSINESS CREDIT, 200 GALLERIA PARKWAY, N

Free format text: SECURITY INTEREST;ASSIGNOR:DRAPER CORPORATION;REEL/FRAME:004539/0198

Effective date: 19860328

AS Assignment

Owner name: DRAPER CORPORATION, GREENSBORO, NORTH CAROLINA A C

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:CITICORP INDUSTRIAL CREDIT, INC.;REEL/FRAME:004664/0583

Effective date: 19860331