Disposable razor with sliding cap
BACKGROUND OF THE INVENTION 
     This application is a continuation-in-part of copending application Ser. No. 108,747 filed Dec. 31, 1979, by Peter Bowman and Allan S. Frieze, now U.S. Pat. No. 4,328,615, issued May 11, 1982 entitled RAZOR BLADE ASSEMBLY WITH MOVABLE COVER CAP. 
    
    
     The principal prior art over which this invention is an improvement is cited in said copending application, the most pertinent of which are U.S. Pat. Nos. to: King 1,287,338, Pinter 2,122,263 and Cutler 2,744,319. 
     King &#39;338 shows a safety razor with a blade guard. The guard is removable and reversible; in one position of the guard, the blade edge is exposed and the razor is operable. In the reversed position, the guard protects the blade edge. 
     Pinter &#39;263 shows a scraper device including a blade for removing paint spots accidentally applied to glass. The device includes a &#34;trunk buckle&#34; latch or an &#34;over center&#34; lever for moving a protective plate to and fro over the edge of the blade to expose or protect the blade, as desired. 
     Cutler &#39;319 shows a carrier for a double edge razor blade which is removable and reversible relative to the razor body. In one position of the carrier, a first blade edge is exposed and the second blade edge is covered. In the reversed position of the carrier, the first blade edge is covered and the second blade edge is exposed. 
     SUMMARY OF THE INVENTION 
     The present invention provides a novel disposable razor of all-plastic construction, save the blade package, which is of relatively simple design and susceptible of high-speed mass production methods necessary for commercial success in the disposable razor market. 
     The razor consists essentially of a handle molded integrally with a blade seat or blade package platform to define a single piece-part. The second plastic piece-part is a sliding blade or cap cover. Thus, if the blade package is treated as a separate entity, the razor is basically composed of three elements, i.e., a plastic sliding cover, a combined plastic handle and blade support, and a blade package. 
     Note that the term &#34;blade package&#34; or blade means is intended to denote one or more single edge blades. 
     Therefore a razor embracing certain features of the present invention may comprise a plastic handle including a contiguous seat member for supporting blade means, said handle and seat member defining a single piece-part, blade means carried by said seat member and a plastic cap slidable on said seat member, said cap and said seat member being formed with interlocking elements which facilitate relative motion through a definite stroke between the cap and the seat member while precluding separation of the cap and seat member. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     Other features and advantages of the invention will become more apparent from an examination of the succeeding specification when read in conjunction with the appended drawings, in which: 
     FIG. 1 is a plan view of the back side of the razor; 
     FIG. 2 is a side view of FIG. 1 as observed in the direction of the arrows 2--2; 
     FIG. 3 is a top plan view of the razor; 
     FIG. 4 is a sectional view of FIG. 3 as viewed in the plane of line 4--4 and in the direction of the arrows; 
     FIG. 5 is a sectional view of a portion of the illustration of FIG. 4 as viewed in the plane of the line 5--5 and in the direction of the arrows; and 
     FIG. 6 is a vertical section of the assembled razor taken in the plane of line 6--6 of FIG. 3 as viewed in the direction of the arrows. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, the reference numeral 11 designates a plastic disposable razor having a handle 12 formed integrally (molded) with a blade seat member 13, a blade package B and a sliding cap or blade cover 14 having side walls 16--16. 
     The side walls 16--16, defining flexible flanges, are formed with exterior serrations or ribs 17 to generate friction during manual grasping as will be more apparent hereinafter. 
     The serrations extend substantially throughout the cap side walls and run into the top surface of the cap as is most apparent in FIGS. 2 and 3. 
     The junction of the top surface and each side wall is formed with an arcuate cut-out which in combination with the serrations 17 provides comfortable locations for grasping the cap 14 manually. 
     The cap 14 is formed with a block 19 having a face 21 molded with two spaced recesses 20-22. The cap also has a pair of claws or lugs 23--23 molded integrally with side walls or flexible flanges 16. 
     The face 21 of block 19 and the shoulders 24--24 of the claws define a track or guide which straddles a rail 26 formed on each end of the blade seat member 13. The rail 26 has a face or shoulder 30 which is in face-to-face contact with shoulders 24--24. 
     The rail 26 is formed with a protuberance 27 which interlocks selectively with recesses 20 and 22 of the block as the cap 14 is moved relative to the seat member 13 through a definite stroke from a first position in which the blade package is exposed for shaving (see solid line position of cap in FIG. 6) to a second position in which the blade package is covered (dotted line position of cap). 
     It is entirely within the contemplation of the invention that the location of the protuberance 27 and the recesses 20 and 22 be reversed, i.e., protuberance on the block 19 and recesses on rail 26. Correspondingly, the position of the rail, the claws and the block could be reversed, i.e., rail on cap and block and claws on blade support. 
     The blade package B which in the present embodiment includes two blades 31 and 32 and blade spacer 33 is secured to the seat member 13 by means of plastic rivets 34--34 molded integrally with the seat member and subsequently &#34;upset&#34; to form heads 36--36 in well known fashion. 
     The cap 14 is assembled to the blade package B and seat member 13 by placing the cap in proper register and pressing the cap down upon the seat member so that side walls 16--16 flex outwardly and thence inwardly as shown in FIG. 5 to effect a snap-on action and as described in greater detail in said copending application. 
     The razors are shipped to point of sale with the cover 14 in the second or closed position (FIGS. 4 and 6). To avoid premature motion of the cover 14, the protuberances 27--27 are molded with a frangible nib 25 to block motion of the cap 14 during transit. 
     When the customer moves the cap 14 to the first position exposing the blade package for shaving, the rib is destroyed and has no further function or effect. 
     As is most apparent in FIG. 4, the stop members on the cap 14 are defined by the vertical faces 35--35 (forward faces) and 40--40 (rear faces) on the block 19. 
     Correspondingly, the stop members on the seat member are defined by the forward vertical walls 45--45 (which cooperate with vertical faces 35--35) and the after vertical walls 50--50 (which cooperate with vertical faces 40--40).