US3318550A

US3318550A - Tape measure reel

Info

Publication number: US3318550A
Application number: US458583A
Authority: US
Inventors: Quenot Andre
Original assignee: Quenot et Cie SARL
Current assignee: Quenot et Cie SARL
Priority date: 1965-03-13
Filing date: 1965-05-25
Publication date: 1967-05-09
Anticipated expiration: 1984-05-09
Also published as: ES316790A1; GB1071895A; DE1928229U; CH420639A; FR1436086A

Description

May 9, 1967 A. QUENOT y 3,318,550

TAPE MEASURE REEL Filed May 25, 1965 2 sheets-shew 1 F'IGJ May 9, 1967 A. Qui-:NOT v 3,318,550

' TAPE MEASURE REEL Filed May 25, 1965 2 SheetsSheet 2 FIGB /A//Z/l/ United States Patent O ,169 4 Claims. '(Cl. 242-1073,)

The invention relates to a device for winding a coilable tape for linear measurement. Such tapes may be made of steel for instance.

Known devices for winding coilable tapes for linear measurement made of steel, cloth, plastic or similar material, are those where the measuring tape whatever its length is rolled up in a case with the aid of a return spring and they must satisfy in particular two requirements: on the one hand the force of the recoil spring must be sutlicient to ensure the complete rolling up of the tape Without the help of the user; and, on the other hand, the force of the spring must not be too strong or else the automatic winding of the tape might cause the tongue xed at the end of the tape to break, the measurement marks on the tape to be rubbed, and the user to be hurt in using it.

Until now some existing devices did not full these conditions. In fact, the force of the recoil spring is frequently insu'icient, so that at any rate part of the tape remains unrolled outside the case. In good quality devices, where this inconvenience is avoided the force of the recoil spring is suilcient, so that the tape returns to the case rather roughly with the risk of damage as mentioned.

According to the invention there is proposed a tape measuring device comprising a housing, a shank rigidly attached to the housing a spring attached by its inner end to and coiled around the shank, a tape whose inner end is attached to the outer end of the spring and which is coiled to the outside of the spring in continuance of the coiling formation of the latter, the outer end of the tape passing through a slot in the housing so that a desired length of the tape can be uncoiled and withdrawn from the housing, the spring being partially uncoiled from the shank and tensioned thereabout, and can then be released so that the tape re-coils under the force of the tensioned spring, a tape braking member rotatable about the axis of the shank through frictional contact with the tape during re-coiling of the tape and having at least one recess for receiving a braking element, the

arangement being such that when the braking member i attains a predetermined speed Ithe braking element is urged into frictional contact with the inner wall of the housing and thereby reduces the rate of which the tape is re-coiling about the axis of the shank.

The invention will now be described by means of the attached drawings. We show two embodiments of the invention but the invention is by no means limited to these embodiments.

FIG. 1 shows a section of the rst embodiment of the invention.

FIG. 2 is a section along II-II of FIG. 1.

FIG. 3 shows a section of the second embodiment of the invention.

FIG. 4 shows a section IV--IV of FIG. 3.

The device represented in FIG. 1 and 2 consists of a case having tape opening 28 made of a plastic material formed on the upper part 1 and the lower part 2, assembled on top of each other. A

shaft

3a, 3b is the means of joining parts 1 and 2, and gives a lodgement 4 for the screw assembling the case and a slit 5 only in the part of the shaft 3b conjointly with the part 2 for fixing at its inside end a return spring 6.

3,318,550 Patented May 9, 1967 ICC Around the

shaft

3a, 3b is mounted a drum formed of a tirst disk 7, made of metal or plastic material and a second disk 8 made of plastic or other material. The return spring is wound between the two parts opposite the disks 7 and 8. At its outside end is fixed the inside end of the measuring tape 9 passing through a slot 20 of the housing. This is wound round a diameter A, limited on the one hand by the lateral periphery of the disc 7 and on the other hand by the shoulder 10 of the disc 8. The means of guiding the tape 9 between the interior and the exterior of the case have not been represented.

On the upper part of the disc 8 are arranged four

radial lodgements

11, 12, 13 and 14 in each of which is placed a metallic removable braking element 15, respectively 16, 17, and 18 taking the shape of a plaque. When the disc 8 turns, set in motion by friction by the tape 9 winding under the inuence of the recall spring 6 in the case, the elements 15 to 1S are urged by centrifugal force against the interior wall of part 1 of the case. The friction is exercised between the said braking elements and the said peripheral wall brakes the disc 8 which as a consequence stops by friction a sudden winding of the tape in the case.

This force of friction is related:

(l) To the coeicient of the friction f between the elements 15-18 and the interior of part 1 of the case. One can Vary this coemcient of friction by the choice of materials of which the braking elements are made and the condition of the surface in contact with the friction.

(2) To the radius r of the circle described by the centres of gravity of the elements 15-18. The more one increases this radius the more important the braking becomes.

(3) To the mass of m of the elements 15-18.

(4) T othe square of the angular speed w of the elements 15-18.

The equation is:

Where F is the force of the friction, k is a constant, and the other symbols represent the quantities given above.

Owing to this relation to the square of the speed one sees that the force of the friction is very great at `great speed and tends quickly towards zero when the speed tends towards zero.

In the case where a slack length of graduated tape is taken from the case the force of the recoil spring 6 is weak (the slackest position); but in that case the force F 'will be practically zero and will not oppose the recall of a slack length of tape.

We have thus achieved a regulation of speed allowing for a gradual recoil of the tape without any sudden force.

This device can be used with success Whatever maybe the length of graduated tape and applies particularly to measures of great length, (5al0-20-30-50 m., etc.).

In certain instances one can, nevertheless, observe a slipping between the tape and the shoulder 10 of the disc. The effect of braking tof the elements 15-18 then no longer transmits to the tape in the required measure. One can obviate this inconvenience by a variation of the construction as represented in FIGURES 3 and 4.

Here the drum is no longer constructed of two independent discs but on the contrary of a drum in the exact sense of the Word, formed by a cylinder 19, closed at one of its ends by a circular wall 20, the enlarged part 21 of which forms an abutment on the

shaft

3a, 3b. In that case the spring of the recoil 6 always ixed in the slit 5 is wound in the cylinder 19 while the measuring tape 9 is wound on the outside around the cylinder 19. The outv through the Vopening in the housing nposes,` at least one annular guide surface on the tape wound are controlled.

end ot' the tape 9 across an opening 22 provided in the t cylinder 19 (FIGURE 4).

The instruments 15-18 are placed as before and have the same function. Nevertheless, when as a result of the winding of the tape in the case under inuence of the spring of recoil the elements 15-18 are applied by centrifugal force against the inside wall lof the case Y1 and therefore brake the drum by friction, the breaking of the cylinder 19 transmits in its entirety to the tape 9 because of its passage in the opening 22.

The device described in one or other of the two embodiments shown in theexample offer the great advan- Y tagepof allowing a perfect recoil of the tape whilst avoid- 'ing all risks of accident caused by too sudden winding.

In fact the tape winds in a movement which slows down uniformly, which saves it from mechanical damage and limits the risk of hurting the user.

' Y Naturally a number of variations are envisaged within the scope of the invention. The number of braking elernents in particular, their placing -on or under the drum Yas well as the treatment of the contact surface may be difficult and will be determined in each case by the need of obtaining the optimum working conditions.

Iclaim: Y Y

1. A tape measuring device comprisinga housing hav- 'Ying upper and lower walls having an opening, a generally circular shank in said housing which is rigidly attached Y to kthe housing and extendsV approximately centrally axially thereof, tape guide means surrounding said shank and adapted to rotate thereabout, a coil spring attached by its inner end to the shank so as to coil and uncoil about the latter, a ilexible tape located between the spring and said housing and whose inner end is attached to the outer end of the spring while its outer free end can be pulled for measuring purguide means for guiding the tape when it is being unwound for measuring purposes or wound for storage, atleast two Yradially extending recesses Vin said tape guide means, aV

braking member located in each recess; the arrangement being such that the tape can be manually unwound and withdrawn from the housing to a desired extent so as uncoil the spring from an unstressed to a stressed condition and can then be released so that the tape and the spring Vare re-coiled, the tape in its re-coiling action rotating the tape guide means by fricional contact so that the braking members are urged into braking contact with the upper wall of the housing, whereby theY rotational speed of the tape guide means and the rate at which the tape is re- 2. A tape measuring device as claimed in claim y1 wherein the tape guide means is a substantially druml shaped member consisting of interconnected upper and.

gaging said side wall over substantially its complete width. n

4. A tape measuring device comprising a lhousing hav-` ing upper and lower walls, and an opening, a generally r circular shank in said housing which is rigidly attached to the housing and extends approximately centrally axially thereof, tape guide means surrounding said shank and adapted to rotate thereabout, a coil spring attached by its v inner end and having a measuring tape secured tothe louter end thereof, said tape being adapted to be pulled through the opening in the housing for `measuring purposesfat least one annular guide surface on the tape guide means for guiding the tape when it is being un- 25 wound for measuring purposesvor wound for storage, two pairs of diagonally opposed radially extending recesses in said tape guide means, four' tape braking members each located in a respective one of the recesses; theV arrangement being such that the tape can be manually unwound and withdrawn from the housing toa desired extent so as uncoil the spring from an unstressed to a stressed con-V dition and can then be released so that the tape and the spring are re-coiled, the tape in its re-coiling action Vrotating the tape guide means by frictional contact so'that the braking members are urged into braking contact with the upper wall of the housing, whereby the rotational 881,850 3/1908 a Y 948,026 2/1910 1,347,529 7/1920 1,566,594 12/1925 2,586,386Y 2/1952 `2,896,912 7/1959 FRANK J. COHEN, Primary Examiner. WILLIAM S. BURDEN,'Examnerf Wherry f 242-84:52

Ryan 242'-107.6

Flegel .r 2424-8452 Scotchmer 242-8452 Graham i 242-8452 Faugier etal.` 2742-1073 X

Claims

1. A TAPE MEASURING DEVICE COMPRISING A HOUSING HAVING UPPER AND LOWER WALLS HAVING AN OPENING, A GENERALLY CIRCULAR SHANK IN SAID HOUSING WHICH IS RIGIDLY ATTACHED TO THE HOUSING AND EXTENDS APPROXIMATELY CENTRALLY AXIALLY THEREOF, TAPE GUIDE MEANS SURROUNDING SAID SHANK AND ADAPTED TO ROTATE THEREABOUT, A COIL SPRING ATTACHED BY ITS INNER END TO THE SHANK SO AS TO COIL AND UNCOIL ABOUT THE LATTER, A FLEXIBLE TAPE LOCATED BETWEEN THE SPRING AND SAID HOUSING AND WHOSE INNER END IS ATTACHED TO THE OUTER END OF THE SPRING WHILE ITS OUTER FREE END CAN BE PULLED THROUGH THE OPENING IN THE HOUSING FOR MEASURING PURPOSES, AT LEAST ONE ANNULAR GUIDE SURFACE ON THE TAPE GUIDE MEANS FOR GUIDING THE TAPE WHEN IT IS BEING UNWOUND FOR MEASURING PURPOSES OR WOUND FOR STORAGE, AT LEAST TWO RADIALLY EXTENDING RECESSES IN SAID TAPE GUIDE MEANS, A BRAKING MEMBER LOCATED IN EACH RECESS; THE ARRANGEMENT BEING SUCH THAT THE TAPE CAN BE MANUALLY UNWOUND AND WITHDRAWN FROM THE HOUSING TO A DESIRED EXTENT SO AS UNCOIL THE SPRING FROM AN UNSTRESSED TO A STRESSED CONDITION AND CAN THEN BE RELEASED SO THAT THE TAPE AND THE SPRING ARE RE-COILED, THE TAPE IN ITS RE-COILING ACTION ROTATING THE TAPE GUIDE MEANS BY FRICTIONAL CONTACT SO THAT THE BRAKING MEMBERS ARE URGED INTO BRAKING CONTACT WITH THE UPPER WALL OF THE HOUSING, WHEREBY THE ROTATIONAL SPEED OF THE TAPE GUIDE MEANS AND THE RATE AT WHICH THE TAPE IS REWOUND ARE CONTROLLED.