The present invention relates to testing the physical integrity of gloves. In particular, the invention relates to testing the integrity of gloves by air inflation to identify any cut, abrasion, or puncture in the glove.
Gloves used by electrical workers or linemen for protection against high voltages are made of an insulative material such as natural or synthetic rubber. It is highly critical that such gloves be properly inspected to ensure they are completely free of defects. Failure to exercise this precaution can have severe consequences including worker electrocution and death.
Defects may result in electrical gloves from a variety of causes including improper folding (the strain on rubber at a folded point is equal to stretching the glove to twice its length), pinpoint puncture by wires or metal shavings, chemical attack by oil or petroleum compounds, rope or cable burns, and ozone cutting. For such reasons, the American Society for Testing and Materials has promulgated a standard, ASTM F496, for field testing insulative gloves of the type used by electrical workers. This standard recommends, among other things, that such gloves be tested before every use by being filled with air and then inspected, by listening or feeling, to detect any escaping air. This procedure also more than satisfies federal requirements (see OSHA 1910.137(b)(2)(ix)) which require, at a minimum, air testing of insulative gloves once-a-day or after any incident reasonably suspected of causing glove damage (see OSHA 1910.137(b)(2)(ii)). Federal requirements also require electrical testing of the gloves at intervals not exceeding six months; however this more elaborate procedure, also called dielectric testing, typically involves high voltages and conductive chemical baths and is seldom employed by workers in the field.
One way to field test electrical gloves is to hold the rolled cuff with one hand so that air is trapped inside and then to apply pressure with the other hand to different areas of the glove while listening for escaping air. With this approach, however, the air tends to escape back out the rolled cuff so that certain portions of the glove, such as the fingers, are not sufficiently inflated and small defects may go undetected. Alternatively, the cuff may be grasped by one hand and twisted lengthwise along the wristband. While sufficient air may then be forced into the thumb and fingers using the other hand, here defects along the wristband portion may go undetected. Moreover, the glove material may be easily damaged by improper rolling or twisting of the glove.
To improve test reliability, various glove testing apparatus have been developed. For example, U.S. Pat. No. 7,143,633 to Westerberg shows an apparatus having a hollow housing forming, at one end, a stacked series of round grooves. The glove's cuff is stretched over a suitably sized one of the grooves and then held in place by a stretchable O-ring, band, or strip. An inflator or bellows, placed at the other end of the housing, is pumped in order to inflate the glove for inspection. However the elastic O-ring or strip may break while being stretched to fit over the cuff so as to render the apparatus inoperable. Moreover, the apparatus uses a removable one-way value to prevent airflow back out the glove during inflation, and both this valve and the O-ring may be easily misplaced. Until replacement parts can be found, the lineman is forced to fall back to a manual method as described above. Also, with its multiple elements, the Westerberg apparatus is relatively expensive to make, so that providing the apparatus for every lineman in the field is costly.
An alternative testing apparatus is shown in U.S. Pat. No. 3,603,138 to Peterson. Here the cuff of the glove is inserted into a round channel of U-shaped cross section. A flexible liner arranged along the inner channel surface is pneumatically driven to force the cuff against the outer channel surface, whereupon the glove can be inflated by the same pressurized air source used to drive the liner. A similar concept is shown in French Pat. Publication 2,643,713 which uses an inner inflatable bladder to force the cuff outwardly to engage a holding means. These apparatus are subject to breakdown, such as if the liner or bladder develop a leak, are relatively expensive to make, and require extensive training in order to use properly.
Other systems for mounting the glove for inflation include spring-loaded jaws, such as shown in U.S. Pat. No. 2,370,945 to Fields, a channel for receiving the beaded edge of the cuff as shown in U.S. Pat. No. 2,074,140 to Bates, a rib for holding the inner wrist portion of the glove by pressure fit as shown in U.S. Pat. No. 2,543,911 to Isaacs, and an elastomeric O-ring that is squeezed between two jaws to expand against the inner cuff portion and so force the cuff portion to engage an outer rim or collar as shown in French Pat. Publication 2,530,813. These systems are either complex to build or fail to secure the glove sufficiently to permit adequate glove inflation.
U.S. Pat. No. 3,820,383 to Van Deventer et al. goes so far as to suggest that the general procedure of inflating the glove and then immediately holding the glove “close to [the] face” to sense leaks is ineffective in detecting small defects and that a better approach is to let the inflated gloves travel on an automatic conveyor “preferably about 15 minutes” so that “leakers” become readily apparent to the naked eye. In Van Deventer, the press fit used to hold the glove's cuff over the lip on the inflating mount may not be sufficient to permit adequate glove inflation. In any event, Van Deventer's approach is clearly not practical either from the standpoint of time or cost for linemen in the field.
In one aspect in accordance with the present invention, a glove is tested by rolling the glove about a spool device starting adjacent the glove's open mouth so as to inflate the glove for inspection. The glove is inflated securely as it is wound about the spool device so as to allow the glove to be adequately inflated for reliable testing. Furthermore, the spool device may be of inexpensive design lacking, for example, multiple parts that might break or require expensive assembly. Thus every lineman may be outfitted with the device, the device may be easily operated without extensive time or training, and the high safety risks that accompany purely manual testing may be avoided.
In a second aspect, an end portion of a glove adjacent the glove's open mouth is received between an opposed pair of elongate holding surfaces formed by a glove testing device and the glove testing device is moved relative to the lengthwise direction of the glove so as to successively seal shut each portion of the glove passed by the device so that air trapped in the glove progressively inflates the glove. This allows a maximum portion of the glove to be properly tested, that is, the lengthwise movement of the testing device relative to the glove may be stopped at any point where the glove is adequately inflated. This avoids, at the same time, overinflation of the glove so as to prevent damage to the glove material.
In a third aspect, the spool or testing device is configured to be moved relative to the glove so as to avoid placing sharp folds in the glove. This prevents damage to the glove caused by the device itself due to overstretching of the glove material. In particular, the device may provide rounded outer surfaces about which the glove may be rolled.
In a fourth aspect, the spool or testing device includes elongate arms and the elongate arms extend in cantilevered arrangement. These cantilevered arms form a lateral gap into which the end portion of the glove may be laterally inserted. Not only does this avoid having to thread the glove's mouth into a narrow channel or to fit the bead of the mouth one circumferential section at a time onto a groove, but these arms can easily receive gloves that have mouths of varying width. Moreover, a certain amount of play is desirably provided by the cantilevered arms so that gloves of varying thickness may be easily accommodated. Preferably, the entire device is molded in one-piece of low-cost material so that the device may be inexpensively purchased and conveniently transported to encourage widespread use in the field.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
a and 4b are sectional views taken along lines 4a-4a in
c is a sectional view corresponding to
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The cantilevered arm arrangement, moreover, easily accommodates gloves of varying thickness. For example, referring to
As indicated in
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From the foregoing description, it will be recognized that the testing or spool device 10 is particularly well suited for use by linemen and electricians in the field. It provides a safe and reliable inspection of an insulative glove, it may be manufactured and sold inexpensively enough for use by each individual, it is sufficiently lightweight and streamlined to be easily carried about, and it may be quickly and conveniently operated without a high degree of skill or training.
Although an exemplary embodiment of the testing or spool device 10 has been described, it will be recognized that variants of the device are possible without departing from at least the broader principles of one or more inventive aspects. For example, the device may be configured for rolling operation without offering the lateral gap or the holding surfaces may form a gap extending only partway through the device. These modifications, however, may make insertion of the glove's end portion into the device more difficult and different thicknesses of gloves may not be as readily accommodated. The device's base portion may be differently configured to include a thumb or hand grip, although this may cause increased material expense and make the device less convenient to carry about in a tight pocket. The outer surface of the arms of the device may be differently shaped, although desirably the arms are not of such flatness as to place sharp folds in the gloves. Other variants are possible and will be apparent to those of ordinary skill in the art.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
This application claims the benefit of U.S. Provisional App. No. 61/409,892, filed Nov. 3, 2010.
Number | Date | Country | |
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61409892 | Nov 2010 | US |