US 3909939 A
An improvement in a safety razor extending along the guard bar between the rinsing slot and the side edge of the guard plate consisting of a row of two-way skin-stretching short narrow grooves, numbering about 40 or 50 grooves, each groove being slanted so as to alternately converge toward the upper and lower ends of adjacent grooves. These small grooves being alternately slanted toward the upper and lower ends of adjacent grooves provide a gentle counter-stretching action to the skin, resulting in a row of 40 or 50 small taut areas extending across the face in advance of the razor blade edge during the shaving operation.
Description (OCR text may contain errors)
 Inventor: Norman L. Dootson, San Francisco,
 Assignees: Winifred M. Colombo, Sausalito,
Califi; David V. Dootson, Chicago, Ill. part interest to each  Filed: Aug. 23, 1973  Appl. No.: 390,933
 U.S. Cl. 30/34.2  Int. Cl. B26B 19/42  Field of Search..... 30/342, 81, 82, 83, 346.58, 30/74.]
 References Cited UNITED STATES PATENTS 1,497,647 6/1924 Smith 30/342 1,651,917 12/1927 Connolly 30/83 X United States Patent [191 [111 3,909,939 Dootson Oct. 7, 1975  SAFETY RAZOR HAVING A ROW on 2,048,565 7/1936 Rodrigues 30/83 SHQRT CONVERGENTLY SLANTED 2,421,205 5/1947 Kingsley 30/77 X COUNTER-STRETCHING TENSION a f 23 GROOVES EXTENDING ALONG THE 3,388,831 6/1968 Hansom... 30/346.58 x GUARD BAR 3,673,684 7/1972 Muntz..... 30/342 Primary Examiner-A1 Lawrence Smith Assistant Examiner-Gary L. Smith [5 7] ABSTRACT An improvement in a safety razor extending along the guard bar between the rinsing slot and the side edge of the guard plate consisting of a row of two-way skinstretching short narrow grooves, numbering about 40 or 50 grooves, each groove being slanted so as to alternately converge toward the upper and lower ends of adjacent grooves. These small grooves being alternately slanted toward the upper and lower ends of adjacent grooves provide a gentle counter-stretching action to the skin, resulting in a row of 40 or 50 small taut areas extending across the face in advance of the razor blade edge during the shaving operation.
1 Claim, 4 Drawing Figures US. Patent Oct. 7,1975
SAFETY RAZOR HAVING A ROW F SHORT CONVERGENTLY SLANTED COUNTER-STRETCHING TENSION GROOVES EXTENDING ALONG THE GUARD BAR The invention relates to single and double edged safety razors, including automatic, adjustable, and other types, and also single and double edge cartridge type blades.
The primary object of this invention is to provide a safety razor which will give smoother and closer shaves uniformly over the entire shaved area, and to retain the sharpness of the blade longer.
The bonded single blade and the twin blade cartridges and several safety razors such as Schick double and injector single edge and Gem single edge and other makes are customarily provided with long parallel tension grooves on the upper area of the guard bar. Other types have short widely spaced parallel grooves on the guard bar. The guard bar surface below these tension grooves and ribs is usually smooth.
My improvement has a plurality of short, straight, narrow tension grooves extending along the guard bar in the normally smooth area, each of the grooves being slanted so as to converge toward alternate of the upper and lower ends of adjacent grooves. These tension grooves are depressed below the surface of this smooth area of the guard bar and do not protrude above the surface.
Perspective views in FIGS. 1, 2, and 3 show my improvement as applied to three different types of razors. FIGS. 1, 2., and 3 show that the construction of my invention is basically the same in all of the different types of safety razors and cartridge blades.
FIG. 4 shows an enlarged view of the guard of the present invention.
My invention is more clearly explained by the following description in connection with the accompanying drawing:
FIG. 1 shows bonded blade 3 enclosed by cap 1 and lower guard plate 2. Plate guard 2 has safety guard bar 6 extending along one side with rinsing slots 4 and parallel tension grooves 5 extending beyond and below blade edge 3. Safety guard bar 6 shows my improvement which consists of a row of alternately slanted short narrow tension grooves 7 and 8 in the normally smooth area of guard bar 6. These grooves 7 and 8 are positioned in relation to each other so as to alternatively converge toward their upper and lower ends all along guard bar 6. My unique arrangement of these convergent tension grooves 7 and 8 controls the tautness of the skin all along the guard bar 6 while shaving, and results in smoother, closer shaves uniformly over the shaved area, and also results in more good shaves per blade which retains it sharpness longer. Dotted lines 9 indicate the handle 9 which grips the blade cartridge in shaving.
FIG. 2 shows my improvement as applied to a Gillette type automatic adjustable safety razor. My improved tension grooves 7 and 8 extend. along guard bar 6. Regular short tension bars 10 extend along guard bar 6 in the usual position.
FIG. 3 shows my improvement as applied to a Schick injector type razor. My improved tension grooves 7 and 8 extend along guard bar 6.
FIG. 4, shows an enlarged fragmentary view of one of the guard bars 6, showing one form of the structure of convergent grooves 7 and 8. While grooves 7 and 8 are shown as merging at their ends, it is obvious that slanted grooves 7 and 8 may also be slightly separated from each other at their ends.
It is obvious that these grooves 7 and 8 may have either open or closed ends. It is also obvious that grooves 7 and 8 may be employed in conjunction with other types of tension grooves or ribs, as shown, or without any other types of tension grooves or ribs. While grooves 7 and 8 may be described as narrow, as to width, and shallow as to depth, and short as to length, it is obvious that the degree of narrowness and shallowness and length may vary. Also grooves 7 and 8 may have either open or closed ends, and may be joined at their upper and lower ends or slightly separated at their ends. FIG. 1 shows closed end grooves 7 and 8 with a narrow smooth strip of the guard bar 6 extending below the lower ends of the grooves.
1. In a safety razor including a guard plate, a blade, means mounting the blade on the guard plate, said guard plate comprising a stationary guard bar with longitudinally extending edge surfaces, and a space between one longitudinal edge of the guard bar and the blade forming a rinsing slot, the improvement comprising a plurality of short, narrow, straight counterstretching tension grooves formed in the surface of the guard bar, the grooves having upper ends terminating adjacent the rinsing slot and lower ends terminating adjacent the other longitudinal edge of the guard bar, each of said grooves is slanted so as to converge toward the ends of its adjacent grooves.