US2900721A

US2900721A - Safety razor with spider stem lock ring

Info

Publication number: US2900721A
Application number: US634527A
Authority: US
Inventors: Warren I Nissen
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1957-01-16
Filing date: 1957-01-16
Publication date: 1959-08-25
Anticipated expiration: 1976-08-25

Description

a- 25. 1959 w. 155m 2,900,721

SAFETY RAZOR WITH SPIDER STEM LOCK RING Filed Jan. 16, 1957 3 Sheets-Sheet 1 if i1" i4 //""f 0 I? 5a 54 3 f i 5/ i 52 l i} 50 INVENTOR. J I 30' MM. :1. W

3 Sheets-Sheet 2 Aug. 25, 1959 w. I. NISSEN SAFETY RAZOR WITH SPIDER STEM LOCK RING Filed Jan. 16, 1957 INVENTOR v MIHWW M M ..-m B f 222 9 5. 3 Z 5 J 9.. mw3\\\\ M iyv fidgu. mm mg I wRwm gtgg/g y Aug. 25, 1959 w. 1. mssEN SAFETY RAZOR WITH SPIDER STEM LOCK RING 3 Sheets-Sheet 3 Filed Jan. 16, 1957 rlfd odflllll INVENTOR.

BY J

WEg2% 2 United States Patent SAFETY RAZOR WITH SPIDER STEM LOCK RING Warren l. Nissan, Marblehead, Mass, asslgnor to The Gillette Company, Gillette Park, Mass, a corporation of Delaware Application January is, 1951, Serial No. 634,527

1 Claim. c1. 30--60.5)

The present invention comprises a safety razor of the sectional cap type of new and improved construction in that the parts of the razor are more securely locked against disengagement than heretofore and at the same time its cost of production is reduced both by simplifying the operation of assembling the razor and utilizing less I expensive parts than have been hitherto considered necessary.

In the normal operation of safety razors of this type, the sections are arranged normally to move slightly more than 90". from closed to open positions but become disengaged from the spider if allowed by accident or otherwise to move beyond their predetermined open position. The opening movement of the sections has been heretofore limited by providing a stop screw in the end of the spider stern. This has required the longitudinal drilling and tapping of a small diameter stem which is a troublesome operation resulting in frequent breakage of the stem or the tap. The prior construction also requires the employment of a special stop screw which in itself is not entirely satisfactory since occasionally the screw will not be properly set in the assembling operation and also it may work loose in use. Heretofore it has been considered necessary to insure against such occurrence by providing special lugs on the spider arms as a stand-by to prevent disengagement of the cap sections in case the stop screw fails for any reason.

The present invention obviates all of the difficulties above-mentioned and at decreased cost of manufacture provides a structure which is reliable and positive in action. It is characterized by a solid spider stem in the preparation of which the former drilling and tapping operations are discarded and in place of a special stop screw is employed a split ring that is brought into place by a simple and quickly etfected step in the assembling operation.

These and other features of the invention will be best understood and appreciated from the following description of a preferred embodiment thereof, selected for purposes of illustration and shown in the accompanying drawings in which:

Fig. 1 is a view in elevation, partly in section of the razor in closed position.

Fig. 2 is a similar view of the razor in open position.

Figs. 3-9 are all fragmentary views in longitudinal section through the lower end of the razor handle, shown in inverted position.

As herein shown, the head of the razor is of conventional construction and includes a blade seat having stationary guards extending along both sides and permanently connected with a tubular handle 11. A spider, including a central bar 12 and transverse end bars 13, carriesthe pivotally-mounted cap sections 14. The head is designed to receive a blade 15 which is longitudinally slotted to receive the bar 12 of the spider and to be enclosed between the blade seat and cap sections when the razor is closed as shown in Fig. 1.

The spider is provided with a solid stem 16 externally 2,900,721 Patented Aug. 25, 1959 threaded in an intermediate lower portion. Below the thread the stern has a plain collar portion 17 defined in part by a circular groove 18 having inclined annular walls. Below the groove 18 is a plain end portion 19 of the same diameter as the portion 17 already mentioned as best shown in Fig. 3. The whole lower end portion of the stem just described is a solid integral element and is readily produced by conventional screw machine procedure.

The handle 11 carries as an extension thereof a tubular nut 30 provided with an external shoulder abutting the lower end of the stationary handle and having a reduced inner end 31 which is internally threaded for engagement with the threaded end of the stem 16. The outer portion of the nut 30 is counterbored to provide a recess 30'. The reduced inner portion of the nut 30 is again counterbored to provide a shoulder 32' and a bore or recess 32, 33' and beyond the recess 32 the nut is again counterbored to provide an annular inner shoulder and a third recess 33 of still smaller diameter but sulficiently large to clear the thread of the stem 16. The nut 30 is rotatably retained on the handle 11 by an internal circular rib 34 of the handle which is freely movable in a corresponding circular groove in the end portion 31 of the nut.

The longitudinal movement of the stem in the nut 30 is limited by a split ring 20 of soft or non-resilient metal of such diameter that it may be expanded and forced over the endmost plain portion 19 of the stem and contracted in the circular groove 18. When assembled upon the stem in that manner, the outer diameter of the ring 20 is just sufficient to clear the inner diameter of the recess 32 of the nut 30, so that while moving within that recess the ring 20 is positively prevented from expanding and being dislodged from its contracted position upon the stem. 0n the other hand, the recess 30 is of sulficient diameter to permit the ring 20, when expanded, to pass freely over the end portion 19 of the stem.

The operation of assembling the ring 20 is illustrated in Figs. 36 and is carried out with the assistance of a tubular collet 40 having an outside diameter such that it completely fills the bore in the outer end of the nut 30 and an inwardly tapering annular flange 41 at its lower end. Cooperating with the collet 40 is a punch 50 having at its lower end a recess 51 surrounded by an annular shoulder 52. The diameter of the punch 50 is such that it-just fills the collet 40 while the recess 51 serves to receive the plain end portion 19 of the spider stem and register it in alignment with the punch.

In assembling the ring 20 upon the stem, the nut 30 is first turned to lower the stem and close the cap sections as shown in Fig. l. The stem is represented as being in this condition in Figs. 3-6 but with the razor in inverted position so that the ring 20 may be dropped by gravity into the collet 40. The correct relative position of stem and punch is established by the fitting of the end 19 of the stem in the recess 51 of the punch. The collet 40 is now lifted and the ring 20 is forced against the inner surface of the tapering shoulder 41 and contracted until it is seated securely within the circular groove 18 of the stern. In the subsequent elevation of the spider in opening the razor, the ring passes into the recess 32 whose walls thus encase the ring 20, and wherein it is free to move until arrested by the annular shoulder at the inner end of the recess. Upward movement of the stem is thereupon positively arrested, the opening movement of the cap sections 14 is limited, and the disengagement of the razor parts is positively prevented.

If on the other hand it becomes necessary to disassemble the razor, the procedure indicated in Figs. 7-10 may be followed. The razor is first closed and the stem brought to the position shown in Fig. I, where the ring 20 is fully withdrawn from the recess 32. With the stem in this position a hollow punch 60 having an end recess 61 and an annular flange 62 is brought into play. The recess 61 of the punch receives the end section 19 of the stem while the flange 62 forces the ring 20 inwardly causing it to expand by its engagement with the inner tapered wall of the circular groove 18 and to pass downwardly upon the plain collar portion 17 of the stem. The ring 20 is thus expanded as shown in Fig. 8, and when the punch 60 is withdrawn, the ring is free to pass outwardly over the end of the stem.

It will be understood that when the collet 40 is lifted in contracting the ring 20 the stem itself is held stationary by the punch 50.

Having thus disclosed my invention and described in detail an illustrative embodiment thereof, I claim as new and desire to secure by Letters Patent:

In a safety razor, a spider stem having an externally threaded portion bounded by a smooth cylindrical end section of less diameter than the thread and having a circular groove therein, a ring retained in said groove and movable with said stem, and a nut threaded on said stem having a bore, the bore including an intermediate recess portion terminating in' an inner shoulder, said intermediate recess portion having a diameter suificient to permit said threaded portion and said end section of said stem carrying said ring to move freely therein, said ring being movable with said stem into contact with said inner shoulder for limiting the movement of said stem, the clearance between the intermediate recess portion and the cylindrical end section of said stem being less than the thickness of said ring, an inner recess portion connected to theintermediate recess portion having a diameter sufficient to permit said externally threaded portion of said stem to move therein, and an outer recess portion connected to the intermediate recess portion, said outer recess portion having a diameter sufficient to permit said ring to be slid over said end portion of said stem and to be placed in the groove therein, said groove having a tapered wall adapted to expand said ring when the, latter is forced inwardly and longitudinally of said stem.

References Cited in the file of this patent UNITED STATES PATENTS 1,816,657 Segal July 28, 1931 2,060,520 Muros Nov. 10, 1936 2,079,245 Dalkowitz May 4, 1937 2,309,549 Swann Jan. 26, 1943 2,356,188 Testi Aug. 22, 1944 2,361,332 Testi Oct. 22, 1944 2,363,449 Muros Nov. 21, 1944 2,363,608 Stampleman et a1. Nov. 28, 1944 2,546,406 Rauglas Mar. 27, 1951 2,753,628 Mass July 10, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,900, 721

August 25, 1959 Warren I. Nissen It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 18, strike out "33'" and insert the same after "shoulder" in line 19, same column; column 4, line 25, list of references cited, for "Muros" read Stampleman et a1. line 26, for "Stampleman et a1." read Muros Signed and sealed this 15th day of March 1960.

(SEAL) Attesl:

KARL H. AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents