[0001]     The invention relates to shaving razors, and blade subassemblies therefor and methods of manufacture.  
         [0002]     Shaving razors often include a plurality of blades that are secured in a desired position in a plastic housing. The housing is often provided with a guard with fins or other skin engaging structures made of elastomeric material in front of the blades, and a cap on which the skin can slide behind the blades. A shaving aid (e.g., a lubricant agent dispensing mechanism) can be incorporated into the cap and, in some cases, the guard. The blades can be stationary or movable, and the housing can be fixed to a handle or movably mounted on the handle, to, e.g., assist in following the contours of the skin during shaving.  
         [0003]     Examples of some different types of shaving razors are described in U.S. Pat. Nos. 5,313,706; 5,369,885; 5,416,974; 5,546,660; 6,032,372; 6,145,201; 6,161,288; 6,216,345; 6,216,561; and 6,397,473.  
       SUMMARY OF THE INVENTION  
       [0004]     In one aspect, the invention features, in general, a subassembly for a shaving razor that includes a plurality of elongated metal blades that are secured to each other as an integral unit. The plural blades have cutting edges defining a shaving surface, and are secured to each other by weld connections at their respective longitudinal ends.  
         [0005]     Particular embodiments of the invention may include one or more of the following features. In particular embodiments, the longitudinal ends of the blades are bent and are transverse to the cutting edges. In some embodiments, the unit includes two metal plates, and one set of longitudinal ends are connected by first weld connections to a first metal plate, and the other set of longitudinal ends are connected by second weld connections to a second metal plate. The plates can have a stainless steel base and an aluminum cladding thereover. In some other embodiments, one set of longitudinal ends of the blades overlap and are welded to adjacent ends at one side of the unit, and the other set of longitudinal ends of the blades overlap and are welded to adjacent ends at the other side of the unit. In some embodiments each blade includes an elongated cutting member having a cutting edge and an elongated support to which the elongated cutting member is attached, with the longitudinal ends of the elongated support being welded to each other at the two sides. In some other embodiments, each blade includes an elongated cutting member portion having a cutting edge and an integral elongated support portion bent downward from the cutting member portion, with the longitudinal ends of the elongated support portion being welded to each other at the two sides. In still other embodiments, each blade includes an elongated cutting member having a cutting edge, and the longitudinal ends of the elongated cutting member are welded to each other at the two sides. The subassembly can have two blades, three blades, four blades or five blades or more. The cutting edges can be located in a common plane. The subassembly can have a snap-fitting structure for connection to a housing of a shaving razor.  
         [0006]     In another aspect the invention features, in general, a shaving razor including a subassembly as already described, and a housing having a recess in which the subassembly is secured.  
         [0007]     In another aspect the invention features, in general, a method of making a shaving razor that includes providing a plurality of elongated metal razor blades having cutting edges and first and second longitudinal ends, positioning the cutting edges parallel to each other and spaced from adjacent cutting edges so as to define a shaving surface, connecting the first longitudinal ends to each other and the second longitudinal ends to each by welding while the cutting edges are maintained parallel to each other.  
         [0008]     Particular embodiments of the invention may include one or more of the following features. In particular embodiments a fixture is used to align the blades in parallel planes and to position the cutting edges at desired positions. The fixture has slots to align the blades and stop surfaces to position the cutting edges. The integral unit of blades is positioned into a recess in a housing. The recess can be open to the top, with, e.g., the integral blade unit being lowered into the recess and held in place by clips or by snap-fitting, or the recess can open to the bottom, with the integral blade unit being raised into the recess.  
         [0009]     Embodiments of the invention may include one or more of the following advantages. Automated assembly of razor blade cartridges can be simplified by installing all of the blades as a unit in a single step. The geometry of the cutting edges with respect to each other can be set prior to assembly, e.g., with a fixture, and tightly controlled and varied, if desired. The subassembly of blades can be removably mounted in a housing and replaced with a new subassembly as the blades become spent, thereby decreasing the parts that are disposed and reusing more parts. Also, integrated blade unit subassemblies can be manufactured with a variety of different blade geometries, with, e.g., different blade tangent angles, exposures, and/or spans, and the different subassemblies can all be used with a common design for the rest of the cartridge into which they are inserted, simplifying part count and tooling at the same time that a variety of different geometries can be easily implemented.  
         [0010]     Other advantages and features of the invention will be apparent from the following description of particular embodiments thereof and from the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a partial, perspective view of a shaving razor.  
         [0012]      FIG. 2  is an exploded, partial, perspective view of the  FIG. 1  shaving razor.  
         [0013]      FIG. 3  is a perspective view of a blade subassembly of the  FIG. 1  shaving razor.  
         [0014]      FIG. 4  is a plan view of the  FIG. 3  blade subassembly.  
         [0015]      FIG. 5  is a front elevation of the  FIG. 3  blade subassembly.  
         [0016]      FIG. 6  is a side elevation of the  FIG. 3  blade subassembly.  
         [0017]      FIG. 7  is a perspective view of a blade of the  FIG. 3  blade subassembly.  
         [0018]      FIG. 8  is a partial diagrammatic plan view illustrating blade and side plate components of the  FIG. 3  blade subassembly.  
         [0019]      FIG. 9  is a diagrammatic side view of fixture used in the manufacture of the  FIG. 3  blade subassembly.  
         [0020]      FIG. 10  is a diagrammatic, partial, exploded view of an alternative embodiment of a blade subassembly that does not have side plates.  
         [0021]      FIG. 11  is an elevation of an alternative embodiment of a blade subassembly that is replaceable.  
         [0022]      FIGS. 12-13  are perspective views of alternative, one-piece blade constructions.  
         [0023]      FIGS. 14-16  are a perspective view of two-, three- and four-blade alternative subassemblies, respectively, for use in the  FIG. 1  shaving razor. 
     
    
     DETAILED DESCRIPTION  
       [0024]     Referring to  FIG. 1 , shaving razor  10  includes plastic housing  12 , blades  14  secured in housing  12 , cap  16 (including a lubricating strip), handle  18 , connecting piece  19  (which is pivotally connected to housing  12  and removably connected to handle  18 ), and elastomeric guard  20  which has fins  22 . There are five blades  14  having cutting edges  28  (see  FIG. 7 ) that define a shaving surface. As appears from  FIG. 2 , blades  14  are provided in an integrated blade subassembly  13  that mounts in recess  21  in housing  12  from the top and is held in place by two clips  23 , only one of which is shown in  FIG. 2 .  
         [0025]     Referring to  FIGS. 3-8 , blade subassembly  13  includes five blades  14  and two side plates  24 . Plates  24  have a stainless steel base and an aluminum cladding thereover for corrosion resistance. However, corrosion resistance can be achieved by other means and materials, such as by the contact with a separate cartridge component that acts as a sacrificial anode such as an aluminum clip or a separate zinc component.  
         [0026]     Each blade  14  includes an elongated cutting member  26  having cutting edge  28  and elongated support  30  to which cutting member  26  is attached by spot welds  32 . Elongated support  30  has an angled section along its length, with a short upper portion  34  and longer base portion  36 . The longitudinal ends  38  of base portion  36  are bent 90°, and are secured to side plates  24  by spot welds  40 .  
         [0027]     Alternatively, the elongated cutting members could be one-piece constructions having a cutting edge portion and an integral bent base portion, as shown, e.g., for one-piece complex member  39  in  FIG. 12 , or not even have a bent base portion, as shown, e.g., for one-piece simple cutting member  41  in  FIG. 13 .  
         [0028]     Referring to  FIG. 9 , fixture  42  is used to position blades  14  while they are welded to side plates  24  by spot welds  40 . Fixture  42  has base member  44  that includes slots  46  that receive base portions  36  of elongated supports  30  of blades  14 . Bladder  46  provides an upward force to the bottoms of base portions  36 , to cause cutting members  26  to abut angled surfaces  48  of alignment block  50 , and cutting edges  28  to contact corners  52 , thereby placing the cutting edges  28  in the desired position to define a shaving surface, and providing the desired blade tangent angle for cutting members  26 . With blades  14  properly positioned in slots  46  and biased upward against surfaces  48  and corners  52 , side plates  24  are welded to bent longitudinal ends  38 , resulting in an integral blade subassembly  30 , that can then be simply inserted into recess  21  and moved into position in housing  12  and secured therein by clips  23  ( FIGS. 1, 2 ). Alternatively, the blades could also be rear mounted into a cartridge housing that has a recess  21  that opens from the bottom. Also, if desired, alignment block  50  can allow for different blades to have different blade tangent angles, exposures and/or spans by different positions for angled surfaces  48  and corners  52  of alignment block  50 .  
         [0029]     Referring to  FIG. 10 , alternative blade subassembly  60  (shown prior to attachment of the last blade  62 ) differs from blade subassembly  30  in that it does not have side plates  24 , but instead has offset extensions  64  on the longitudinal ends  66  that overlap and are welded to portions  68  of the prior blade  62  by welds  70 .  
         [0030]     Referring to  FIG. 11 , alternative blade subassembly  76  has angled side plates  78  that are snap-fit into housing  12  and held in housing  12  without the need for clips  23 . When the blades need to be replaced, instead replacing the entire cartridge (including housing  12  and connecting piece  19  as well as the blades) one pushes the used subassembly  76  out from the bottom, and simply snaps in a new subassembly  76 , permitting the housing  12  and connecting piece  19  to be used multiple times. Alternatively, side plates  78  could be slidably mounted in guide slots (not shown) in the housing to allow the blades to be floating, sliding up and down, in the cartridge.  
         [0031]     Other embodiments of the invention are within the scope of the appended claims. For example, other techniques (such as elastomeric materials, magnetism, solenoids, and springs) can be used in place of bladder  46  to bias the blades  14  into the proper position. Other structures or shapes can be used in place of angled surfaces  48  and corners  52  to align the blades. Oval spots and dual spots can be used in place of the round spot welds  40  and  70 .  
         [0032]     There can be any number of blades, (e.g., 2, 3, 4, 5, 6, 7, etc). Two-, three- and four-blade subassemblies  80 ,  82 ,  84 , respectively, are shown in  FIGS. 14-16 , respectively. Also, the cartridge and handle may be integral parts such as a disposable razor.  
       LISTING OF REFERENCE NUMERALS  
       [0033]     shaving razor  10   
         [0034]     plastic housing  12   
         [0035]     integrated blade subassembly  13   
         [0036]     blades  14   
         [0037]     cap  16   
         [0038]     handle  18   
         [0039]     connecting piece  19   
         [0040]     elastomeric guard  20   
         [0041]     recess  21   
         [0042]     fins  22   
         [0043]     clips  23   
         [0044]     side plates  24   
         [0045]     cutting member  26   
         [0046]     cutting edge  28   
         [0047]     elongated support  30   
         [0048]     spot welds  32   
         [0049]     short upper portion  34   
         [0050]     longer base portion  36   
         [0051]     longitudinal ends  38   
         [0052]     one-piece complex cutting member  39   
         [0053]     spot welds  40   
         [0054]     one-piece simple cutting member  41   
         [0055]     fixture  42   
         [0056]     base member  44   
         [0057]     slots  46   
         [0058]     angled surfaces  48   
         [0059]     alignment block  50   
         [0060]     corners  52   
         [0061]     alternative blade subassembly  60   
         [0062]     last blade  62   
         [0063]     offset extensions  64   
         [0064]     longitudinal ends  66   
         [0065]     prior blade portions  68   
         [0066]     welds  70   
         [0067]     alternative blade subassembly  76   
         [0068]     angled side plates  78   
         [0069]     two-blade subassembly  80   
         [0070]     three-blade subassembly  82   
         [0071]     four-blade subassembly  84
A subassembly for a shaving razor that includes a plurality of elongated metal blades that are secured to each other as an integral unit. The plural blades have cutting edges defining a shaving surface, and are secured to each other by weld connections at their respective longitudinal ends.