Hand coverings

In this invention a novel configuration of the crotch area between the thumb and first finger has been found to impart unexpectedly good durability and resistance to splitting of the seam in this crotch area. The configuration is one in which the geometry of the crotch area is formed by two arcs separated by a short substantially straight portion, and in which the radii loci of the two arcs is centered in the space between the thumb and first finger.

CROSS-REFERENCE TO RELATED APPLICATIONS 
This application is based on Provisional Application Ser. No. 60/035,712, 
filed Jan. 16, 1997. 
FIELD OF THE INVENTION 
This invention relates to hand coverings having improved durability and 
resistance to splitting along seam areas between the thumb and index 
finger. 
BACKGROUND OF THE INVENTION 
It has been a problem in hand covering constructions that in uses in which 
the thumb is flexed frequently, the seam in the crotch area between the 
thumb and first index finger fails. 
In typical glove constructions, the crotch area between the thumb and index 
finger comprises a curved area having an arc defined by a single radius 
with its loci at P as shown in FIG. 1 and as shown in U.S. Pat. Nos. 
5,566,405 and 5,560,044 to Masley. 
Alternatively, said crotch area is defined by two arcs each of which have 
the radii loci centered over near the crotch of the third and fourth 
finger (see P.sub.1 and P.sub.2 in FIG. 2). 
SUMMARY OF THE INVENTION 
In this invention a novel configuration of the crotch area between the 
thumb and first finger has been found to impart unexpectedly good 
durability and resistance to splitting of the seam in this crotch area. 
The configuration is one in which the geometry of the crotch area is 
formed by two arcs separated by a short substantially straight portion, 
and in which the radii loci of the two arcs is centered in the space 
between the thumb and first finger.

DETAILED DESCRIPTION OF THE INVENTION 
The configuration of the glove of the invention is shown in FIG. 3. It is 
seen that the crotch area, i.e. the area within the dotted circle is 
configured so as to define an arc X-X.sup.1 having the center of a circle 
defined by the arc located at L.sub.2. It is seen that an arc Y-Y.sup.1 
defines a portion of a circle having its center located at L.sub.1. It is 
also seen that the two arcs are separated by a substantially straight 
portion A-A.sup.1 between the two arcs. It is understood that in portion 
A-A', by substantially straight is meant that the portion can be slightly 
curved if the radius of the arc so formed is a number of times greater 
than the radii of the arcs X-X' or Y'Y', e.g., at least 10 times or 50 or 
100 times greater. 
It has been found that when gloves are made by adhering two overlying 
cut-out patterns along the periphery by heat sealing, by sewing or by use 
of an adhesive, and when the crotch area is configured as described above, 
the glove has good durability and resistance to splitting in said crotch 
area. Alternatively, the gloves can be made by dipping a glove form with 
the inventive crotch configuration in a dispersion or latex to make a 
three-dimensional glove. The use of two separated radii, each being 
located in close proximity to the hands' natural flex points, greatly 
reduces the buildup of stress in the glove seams as the hand is flexed. 
This becomes particularly important when the extensibility of the glove 
material is low or the modulus is high which creates high stress on the 
seam in that crotch area of the single radius glove. This high stress will 
lead to premature failure of the seam in the crotch area, and limits the 
commercial value of such a product. 
The hand covering can be an outer glove or mitten, or can be a liner 
designed to fit under an outer glove or mitten. It can also be a 
surgical-type glove, or similar glove, i.e., one that provides a 
protective barrier to fluids. 
The two patterns can be made of any material commonly found in hand 
covering applications. These include coverings made of rubber, latex, 
plastic, fabric knits, wovens, non-wovens, or laminates of these 
materials, and the like. The hand covering materials can include layers 
that impart insulative properties or waterproofness and which pass water 
vapor, such as microporous plastic films or membranes or foams. Examples 
are microporous polyolefins, microporous fluoropolymers such as 
microporous polytetrafluoroethylene, hydrophilic polyurethanes or 
polyetheresters, polyacrylates, polyamides, and the like. 
For materials that are thermoplastic or thermosettable, the two patterns 
can simply be heated around the periphery (wrist area excluded, of course) 
to weld the two patterns together. Alternatively, an adhesive bead can be 
applied around the periphery. 
Tests have shown when a glove construction follows a pattern where the `V` 
crotch between the thumb and first finger is shaped very similar to the 
`V` crotch between any of the other fingers and is formed by a single 
radius, the construction resulted in splitting of the glove seams at the 
thumb crotch. This invention overcomes the splitting problem. 
Glove patterns can be sealed together using heat, radio-frequency, 
ultrasonic means, thermo impulse techniques, induction techniques or laser 
means. 
EXAMPLE 
A glove was constructed from a two layer laminate of expanded 
polytetrafluoroethylene and a polyether-polyester nonwoven fabric made in 
accordance with the teachings of U.S. Pat. No. 5,036,551. Lamination was 
achieved utilizing a continuous layer of polyurethane adhesive. Shapes of 
a glove were cut from the laminate and heat sealed together to form a 
glove having the crotch configuration of the invention. Strength of the 
crotch area was good.