US3516281A

US3516281A - Wear-testing method

Info

Publication number: US3516281A
Application number: US781779A
Authority: US
Inventors: Stephen E Taub
Original assignee: INST RESEARCH COUNCIL Inc
Current assignee: INST RESEARCH COUNCIL Inc
Priority date: 1968-12-06
Filing date: 1968-12-06
Publication date: 1970-06-23
Anticipated expiration: 1987-06-23

Description

June 23, 1970 s. E. TAUB 3,516,281

WEAR-TESTING METHOD Filed Dec. 6. 1968 3 Sheets-Sheet 1 WVENTOR STEPHEN E,TAUB

June 23, 1970 s. E. TAUB 3,516,281

wma-TESTING METHOD Filed nec. e. 196e s sheets-sheet 2 INVENTOR STEPHEN E. TAUB June 23, 1970 s. E. TAuB 3,516,281

WEAR-TESTING METHOD Filed Dec. 6, 1968 3 Sheets-Sheet 3 STEPHEN E,TAUB

United States Patent O 3,516,281 WEAR-TESTING METHOD Stephen E. Taub, Brooklyn, NY., assignor to Institutional Research Council Inc., New York, N.Y., a corporation of New York Continuation-impart of application Ser. No. 633,852, Apr. 26, 1967. This application Dec. 6, 1968, Ser. No. 781,779

Int. Cl. @01u 3/56 U.S. Cl. 73--7 4 Claims ABSTRACT OF THE DISCLOSURE A method for wear-testing floor covering which simulates wear induced by normal walking. The heel of a shoe and a fulcrum means are rst brought into contact with a floor covering disposed on a rotatable table. The shoe is then rotated about the fulcrum means to bring the sole thereof in contact with the oor covering and to also effect rotation of the table so that on the succeeding descent of the shoe, the shoe will contact a different portion of the oor covering. Twisting action is induced while the shoe is in contact with the oor covering to simulate action of a person changing direction on the oor covering.

PRIOR APPLICATION This application is a continuation-in-part of copending, commonly assigned U.S. patent application Ser. No. 633,852, filed on Apr. 26, 1967 now U.S. Pat. No. 3,427,859.

THE INVENTION Described herein is a method for Wear-testing floor covering systems such as, carpeting, tile, etc., which are subjected to wear by abrasion, friction, and pressure, as by feet of people walking thereon. This wear-testing method induces wear in the oor covering systems by simulating ambulatory process.

PRIOR ART Various wear-testing methods and machines are known, but they have not been successful. The pressure on the carpeting and the shape of Wear tool are not variable on most of the known testing machines. The type of wear induced does not resemble the wear induced by a person walking on the carpet and the results obtained do not correspond to the results obtained under actual use conditions.

OBI ECTS OF THE INVENTION It is an object of the invention to provide a novel Weartesting method which induces wear similar to that of actual use.

It is another object of the invention to provide a novel testing method for producing wear on oor covering with reproducible results.

These and other objects and advantages of the invention will become obvious `from the following detailed description.

DESCRIPTION OF THE INVENTION The method of the invention for inducing wear in a floor covering disposed on a rotatable table with a shoe means, provided with a fulcrum means on the heel portion thereof, comprises advancing a fulcrum means on the heel portion of a shoe means into contact with a floor covering; rotating said shoe means about said fulcrum means until the sole of said shoe means comes in Contact with said oor covering thereby moving said table means; and withdrawing said shoe means away from said floor covering. The method includes an optional step of twisting the shoe, when the sole thereof is in contact with the oor covering, through an angle to simulate a person making a turn. The invention also incorporates a feature which permits lateral movement of the shoe, when it is disposed away from the oor covering, to present a larger wear area.

The apparatus for wear-testing oor coverings comprises a rotatable table provided with means for securing a test specimen thereon, atleast one shoe means mounted over the portion of the said table where the test specimen lies, means for raising and lowering said shoe means whereby first the heel portion of the shoe means contacts the test specimen under pressure and then the sole portion of the shoe means contacts the test specimen, and means for varying the pressure of the shoe means on the test specimen, the said table being rotated by the movement of the shoe means.

The rotatable table may be round and provided about its bottom circumference with wheels or bearings riding on the support means for the table. This arrangement allows the table to remain level when under pressure from the shoe means and to remain rotatable. In a preferred embodiment, the table is provided with means to vary the amount of friction between the table and the wheels so that the amount of force necessary to rotate the table can be varied. This has the advantage that the amount of wear on the test specimen can be varied since as the amount of drag increases, the more energy is required by the shoe means to rotate the table which increases the friction and, therefore, wear between the shoe means and the test Specimen.

While the round table may be made of any hard material, it is preferably made of hard metal and is provided with a top layer of regular wood flooring in order to provide a base as similar as possible to the type of base carpeting is usually used with. For floor coverings which are to be used on a hard surface such as a concrete or stone Hoor, the wood layer may be omitted to provide a similar hard base for the test specimen.

The test specimen, with or without any under layer, is preferably the same size and shape as the rotatable table and is tightly held thereon. One convenient means for holding the test specimen in place is two metal rings which are bolted or screwed to the table, one ring being about the circumference of the table and the second ring about the center of the round table.

The shoe means which are used to induce wear on the test specimen and to rotate the table are mounted above that portion of the table on which the test specimen lies and preferably there are two shoe means on opposite sides of the table so that a greater degree of wear can be induced in a given period of time. The shoe means may be in the shape of a normal mans shoe or a womans high heel shoe in order to determine different types of wear to which the test specimen will be subjected. In a preferred embodiment, the shoe means may be laterally adjustable so that a wide area of wear may be induced on the test specimen.

At least one of the shoe means is adapted so that as the shoe is lowered to the test specimen on the table, rst the heel of the shoe comes in contact with the test specimen and the sole of the shoe means comes in contact with the test specimen while the heel is lifted off the test specimen.

This arrangement not only simulates the wear induced by normal walking, but it also provides a force which turns the table so that the next lowering of the shoe means will come in contact with another portion of the test specimen. This result can be simply achieved by providing the shoe means with a bar or cylinder across the middle or forward portion of the heel of the shoe means so that the bar or cylinder acts as a fulcrum for the shoe means.

In a preferred embodiment of the apparatus, the weartester apparatus is provided with means for twisting the sole of the shoe means while it is in contact with the test specimen which movement simulates the wear induced by a person turning a corner. One simple means for providing this twisting action is to provide the shoe means with a metal plate on the toe of the shoe means which is synchronized to engage a push rod in a pneumatic cylinder. When the sole is in contact with the test specimen, the said push rod pushing the toe plate laterally to provide the twisting movement. The degree of twist can be easily varied by changing the length and/or weed of stroke of the push rod and/or changing the lateral position of the shoe means.

The raising and lowering of the shoe means may be effected by attaching the shoe means to rods connected to overhead cylinders which may be operated hydraulically or pneumatically to force the shoe means upon the test specimen under pressure and then to raise the shoe means for the next cycle. The amount of pressure applied by the said cylinders is preferably varied over a wide range, i.e 1 to 5,000 pounds per square inch, to induce different degrees of wear on the test specimen. The said cylinders are preferably laterally adjustable so that the shoe means may be moved laterally.

In a preferred embodiment of the wear-testing apparatus, the speed of the raising and lowering of the shoe means should be variable so that the apparatus can simulate a varying gait, ranging from a slow Walk to a fast walk or running.

If desired, the apparatus may be provided with an automatic counter to determine the number of times the shoe means comes in contact with the test specimen and may be further provided with an automatic shutoff means so that the apparatus will shut itself off after a predetermined number of steps.

The advantage of the apparatus residues in the fact that the fiber damage, soiling and wear of the resilient carpeting induced by the apparatus is the same as that produced under actual use conditions since the movement of the shoe means is the same as that of a person walking. The test results obtained in a matter of two or three days with the apparatus of the invention would require several years of wear under actual use conditions. Moreover, the wear results are reproducible so that different types of floor coverings can be accurately compared for their durability. The degree of wear of the resilient floor covering can be determined by visual observation, the loss in weight of the covering and/ or the weight of detritus collected. The oor coverings can be rated for different characteristics such as frictional resistance between underlay and carpeting, compression set and carpet life.

Referring now to the drawings:

FIG. 1 is a cross-sectional View of one embodiment of the wear-testing machine of the invention;

FIG. 2 is a partial plan view of the same embodiment along line 2-2 of FIG. 1;

FIG. 3 is a plan view of the same embodiment along line 3-3 of FIG. 1;

FIG. 4 is a plan view along the line 4 4 of FIG. 2, showing the means for laterally moving the shoes;

FIG. 5 is a cross-sectional view of the shoe means as the heel first comes in contact with the test oor covering; and

FIG. 6 is a cross-sectional view of the shoe means as the sole comes in contact with the test floor covering just before the shoe means is twisted.

Referring to the drawings in detail, the entire apparatus is supported by frame 1. Round table 2 is supported on a plurality of wheels or rollers 3 which are arranged about the bottom circumference of the table 2 so that the table 2 will rotate due to the movement of the shoe means. Additional wheels 4 are positioned horizontally about the outer circumference of table 2 to keep the table in a xed lateral position. The table 2 is comprised of a metal base 5 and a wood base `6 thereover which simulates a normal wood oor. To simulate a concrete or stone floor, the wood base 6 is removed. The test specimen 7 of resilient floor covering, with or without an underlay, is laid on the table 2 and is held securely in position thereon by inner metal ring 8 and outer metal ring 9 which are bolted to the table with bolts 10. This prevents lumps or wrinkles forming in the test specimen during the test operation.

Shoes 11 and 12 are mounted directly above the portion of test specimen 7 which is to be subjected to the wear tests and are preferably on opposite sides of the table 2. The said shoes are connected by rods 13 and 14 to

cylinders

15 and 16 which are preferably operated pneumatically and which are synchronized so that both shoes are raised and lowered together. The compressed air or hydraulic fluid is fed under pressure to

cylinders

15 and 16 from a source (not shown) by

tubes

17 and 17a and 18 and 18a to force shoes 11 and 12 upon the test specimen under pressure, hold them in position, and then raise them for the next cycle. The pressure can vary from about 1 to 5,000 p.s.i. The speed of raising and lowering the shoe means is adjusted by varying the operation of the cylinders.

Cylinders

15 and 16 are preferably laterally adjustable and are so mounted on frame 1, whereby a broadened area of Wear is obtained which gives more accurate results since Hoor coverings are not always completely uniform. FIGS. 2 and 4 illustrate one means of moving the shoes laterally after each raising and lowering of the shoe. Each cylinder is attached by a metal rod 19 to a disc 20, said rods :being attached offset from the center of disc 20, whereby turning of disc 20 will bring together or move apart

cylinders

15 and 16. Disc 20 is attached by shaft 21 to notched gear 22 which is turned by the back and forth motion of rod 23 attached to piston 24. To rotate gear 22, rod 23 engages one of the teeth of gear 22 and pushes on it for a predetermined distance following which it retracts and engages a succeeding tooth of gear 22. As gear 22 is rotated at the rate of one notch for each sequence of ascent and descent of the shoes, disc 20 correspondingly rotates, -by means of shaft 21, in increments whereby the cylinders are moved laterally in increments toward or away from each other. By adjusting the radial displacement of rods 19 on disc 20, or by the use of a different size gear 22, the lateral movement of the shoes may be varied.

FIGS. 5 and 6 illustrate the movement of the shoes as they come in contact with the test specimen 7 and a preferred connection with rods 13 and 14. Shoe 11 is provided with a solid block 25 inside thereof which is securely attached to rod 13. The shoe is provided with a lateral metal cylinder or fulcrum 26 on the heel 27. A sleeve 31 is provided on the block 25 having an upwardly opening slot 32 which is adapted to receive the piston rod 13. An enlarged cylindrical portion 33 is secured on the free end of the piston rod 13 and is received within the sleeve. The cylinder includes a downwardly projecting rod 34 which ts within a notch 35 provided in the block 25. In the position illustrated in FIG. 5, the heel of the shoe 11 is swung to a position lower than the toe portion and it is the heel that first contacts the test specimen.

As rod 13 comes down, the back of heel 27 and cylinder 26 contact the flor covering first and as rod 13 continues to descend, the cylinder 26 acts as a pivot with the back of the heel rising off the oor as the sole of the shoe and front portion of the heel corne in contact with the floor covering. This movement causes the table 2 to rotate on rollers 3. It should be apparent, that the table can also be rotated by an independent means when the shoe is in the raised position. By varying the amount of drag on the table, the degree of Wear can be varied.

The location of cylinder or fulcrum 26 on the heel of a shoe is important to the extent that if the cylinder is located too close to the contacting edge of the heel, the cylinder will prevent the heel from contacting the Hoor covering. It has vbeen observed that in order to permit the rear edge of the heel to contact floor covering, as is the case in normal walking, the cylinder should be positioned at about the middle of the heel. This is not a postulate since variables such as gait, diameter of the cylinder, etc., may dictate a different location. Furthermore, in the case of ladies shoes, the area of the heel may be so small that no cylinder would be required. In such an instance, the heel itself would function as the fulcrum.

In order to simulate wear which occurs where a person turns a corner, shoe 11 is preferably provided with a metal plate 28 securely attached to the toe thereof. A pneumatic cylinder 29 with a push rod 30 is mounted so that push rod 30 can push on the plate 28 when the shoe 11 is in the position shown in FIG. 6, which twists the shoe to one side while under pressure. The amount of twist can be varied by changing the length and/or speed of stroke of push rod 30 and/or by changing the lateral position of the shoe. To insure that the heel of the shoe first contacts the floor covering, a biasing member of some sort should be provided to maintain the position of the shoe in the free state as in FIG. 5. In the preferred embodiment, a spring 36 is secured at the upper portion of plate 28, and is suitably secured at the other end to the frame. As the piston rod 13 retracts the shoe from the contacting position, the spring 36 returns the shoe to the position illustrated in FIG. 5.

When the apparatus is operated penumatically, a reduction gear box of standard construction is provided on frame 1, in conjunction with an electric motor. A number of actuating levers may be mounted on the drive shaft extending from the reduction gear box. These levers are mounted on the shaft in predetermined positions and sequentially operate a battery of microswitches, where each micro-switch performs a specific function, such as opening a valve to admit air into a cylinder to force the shoe onto the test specimen, opening a valve to admit air into a cylinder to raise the shoe ott the test specimen, operating a push rod to laterally move the shoe when its sole is in contact with the test specimen, etc.

Any other control system apparent to those skilled in the art, can be adapted to operate the herein described apparatus.

The apparatus is preferably equipped with an automatic counter and an automatic shutoff switch so that the number of steps by the shoes may be counted and the apparatus can be shut off after a predetermined number of steps. While mens shoes have been illustrated in the figures, womens shoes or simulations of shoes of any style can also be used.

Various modilications of the invention may be made without departing from the spirit or scope thereof.

I claim:

1. Method of inducing wear in a resilient floor covering disposed on a rotatable table wherein a shoe means is provided with a fulcrum means on the heel thereof, comprising the steps of:

advancing said fulcrum means and heel of the shoe means into contact with said floor covering; rotating said shoe means about said fulcrum means until the sole of said shoe means comes in contact with said flooring and the heel is no longer in contact therewith, whereby said table is also rotated so that a different portion of said floor covering is presented on the succeeding descent of said shoe means; and withdrawing said shoe means away from said oor covering.

2. Method of claim 1 including the step of moving said shoe means laterally when it is disengaged from said`oor covering to obtain a broadened wear area on said floor covering.

3. Method of claim 2 including the steps of providing a plurality of said shoe means; and twisting at least one of said shoe means through an angle when the sole of said shoe means is in contact with said oor covering to simulate a person changing direction.

4. Method of claim 3 wherein said shoe means is a ladys shoe means with a high heel which functions as the fulcrum means.

References Cited UNITED STATES PATENTS 1,906,175 4/1933 Millet 73-7 2,638,776 5/1953 Aines 73-7 2,895,326 7/1959 Fesperman et al. 73-7 3,134,255 5/1964 Oliver et al. 73-7 3,323,349 6/1967 Savage et al. 73-7 3,382,701 5/1968 Powell 73-7 LOUIS R. PRINCE, Primary Examiner D. M. YASICH, Assistant Examiner