Patent Publication Number: US-6990740-B2

Title: Razor assembly with replaceable cartridge

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority from U.S. provisional patent application No. 60/343,438 filed on Dec. 21, 2001. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   This invention relates to shaving devices in general, and to shaving devices that utilize a replaceable cartridge in particular. 
   2. Background Information 
   Modern safety razors include a plurality of blades disposed within a cartridge that is pivotally or rigidly mounted on a handle. Some safety razors have a disposable cartridge for use with a reusable handle, while others have a handle and cartridge that are combined into a unitary disposable. Although a variety of razor cartridge configurations exist, most include a frame made of a rigid plastic that includes a seat and a cap, and the blades are disposed between the cap and the seat. The cartridge further includes a guard disposed forward of the blades. The guard and the cap orient the position of the person&#39;s skin relative to the blades to optimize the shaving action of the blade. The terms “forward” and “aft”, as used herein, define relative position between two or more things. A feature “forward” of the razor blades, for example, is positioned so that the surface to be shaved encounters the feature before it encounters the razor blades, if the razor assembly is being stroked in its intended cutting direction (e.g., the guard is forward of the razor blades). A feature “aft” of the razor blades is positioned so that the surface to be shaved encounters the feature after it encounters the razor blades, if the razor assembly is being stroked in its intended cutting direction (e.g., the cap is disposed aft of the razor blades). 
   The comfort and performance provided by a particular razor are critical to the commercial success of the razor. Improvements that benefit razor comfort, performance, and ease of use, however significant or subtle, can have a decided impact on the commercial success of a razor. All attachment mechanisms that pivotally mount a replaceable cartridge on the handle of a razor, of which we are aware, utilize a pivotal connection between the replaceable cartridge and the handle. There are several disadvantages to a pivotal connection between the replaceable cartridge and the handle. For example, an attachment mechanism that must mount and pivotally attach the cartridge will likely be more complex that an attachment mechanism that only mounts. A person of skill in the art will recognize that complexity generally adds cost, increases quality and manufacturing issues, and decreases durability. Another disadvantage of a pivotal connection between the replaceable cartridge and the handle is that very often the replaceable cartridge must include features that enable the pivotal connection, and those features increase the cost of the disposable, replaceable cartridge. 
   What is needed, therefore, is a durable razor assembly having a replaceable cartridge of minimal complexity, one that facilitates loading and unloading of the replaceable cartridge, and one that is readily manufacturable. 
   DISCLOSURE OF THE INVENTION 
   It is, therefore, an object of the present invention to provide a durable razor assembly having a replaceable cartridge of minimal complexity, one that facilitates loading and unloading of the replaceable cartridge, and one that is readily manufacturable. 
   According to the present invention, a razor assembly is provided that includes a reusable handle and a replaceable cartridge. The reusable handle includes a grip portion that is pivotally attached to a cartridge seat. The cartridge seat includes a first attachment feature. The replaceable cartridge includes a frame, one or more razor blades, and a second attachment feature. The first attachment feature and the second attachment feature combine with each other to fixedly attach the replaceable cartridge to the cartridge seat. The first attachment feature and the second attachment feature are selectively separable to permit removal of the replaceable cartridge from the cartridge seat of the reusable handle. 
   The present invention razor assembly provides several advantages. For example, the simplicity of the first and second attachment features enables a high quality replaceable cartridge to be manufactured economically. The first and second attachment features fixedly attach the replaceable cartridge to the cartridge seat of the reusable handle and thereby avoid complexities associated with prior art pivotal mounting schemes. Pivotal motion of the replaceable cartridge is accomplished by the pivotal connection between the cartridge seat and grip portion of the reusable handle. The simplicity of the first and second attachment features also increase the ease-of-use of the razor assembly by making the loading and unloading of the replaceable cartridge quite apparent to the user. 
   Another advantage of the present invention is its durability. Presently available razor assemblies that pivotally mount a replaceable cartridge on a handle utilize a pivotal connection between the replaceable cartridge and the handle. The pivotal nature of the connection increases the complexity of the connection and decreases the durability of the connection. The present invention, in contrast, fixedly attaches the replaceable cartridge to the handle. Pivoting of the cartridge is accomplished via the pivotal connection between the grip portion and the cartridge seat of the reusable handle. Because the pivotal connection of the present invention is provided within the reusable handle, the connection can be made more robust and therefore more durable. The first and second attachment features that fixedly attach the replaceable cartridge to the cartridge seat are simplified to increase their durability and decrease their cost. 
   These and other objects, features, and advantages of the present invention will become apparent in light of the detailed description of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a diagrammatic view of a present invention razor assembly, partially sectioned. 
       FIG. 2  is a diagrammatic exploded partial view of the present invention razor assembly. 
       FIG. 3  is a diagrammatic planar partial view of the present invention razor assembly. 
       FIG. 4  is a sectional view of the razor assembly shown in  FIG. 3 , sectioned along line  4 — 4 . 
       FIG. 5  is a sectional view of the razor assembly shown in  FIG. 3 , sectioned along line  5 — 5 . 
       FIG. 6  is a sectional view of the razor assembly shown in  FIG. 3 , sectioned along line  6 — 6 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1–6 , a razor assembly  10  includes a reusable handle  12  and a replaceable cartridge  14 . The reusable handle  12  includes a grip portion  18  and a cartridge seat  20 . The grip portion  18  includes a seat mount  22  attached to one end of an elongated member  24 . The cartridge seat  20  is pivotally attached to the seat mount  22 . The cartridge seat  20  includes a first attachment feature  26  (see  FIG. 2 ). The replaceable cartridge  14  includes a second attachment feature  28 . The first attachment feature  26  and the second attachment feature  28  combine to fixedly attach the replaceable cartridge  14  to the cartridge seat  20 . The first attachment feature  26  and the second attachment feature  28  are selectively separable to permit removal of the replaceable cartridge  14  from the reusable handle  12 . 
   The replaceable cartridge  14  includes one or more razor blades  30  attached to a frame  32 . Depending upon the application, the replaceable cartridge  14  may also include a guard  34  and a shaving aid strip  36  attached to the frame  32 . Guards  34  and shaving aid strips  36  are well known in the art and will therefore not be discussed further here other than to say the present invention is not limited to being used with any particular type of guard  34  or shaving aid strip  36 . 
   In the exemplary embodiment shown in  FIGS. 1–6 , the cartridge seat  20  includes a first arcuately shaped rail  38  and a second arcuately shaped rail  40  in addition to the above-referenced first attachment feature  26 . The seat mount  22  includes a first bracket  42  and a second bracket  44 , each of which includes a channel  46  shaped to receive the rails  38 ,  40 . Alternatively, the brackets  42 ,  44  containing the channels  46  can be attached to the cartridge seat  20  and the rails  38 ,  40  attached to the seat mount  22 . A portion or all of each rail  38 , 40  is received within a channel  46  and can be slidably moved relative to the channel  46  to enable pivotal motion of the cartridge seat  20 . The first attachment feature  26  of the cartridge seat  20  includes a pair of tab pockets  48 , 50 . The second attachment feature  28  of the replaceable cartridge  14  consists of a pair of tabs  52 , 54  shaped so as to be receivable within the tab pockets  48 , 50 . A raised lip  56  (see  FIG. 6 ) or other detent mechanism (e.g. a ball and dimple, etc.) is provided to maintain the tabs  52 ,  4  within the tab pockets  48 , 50 . Other mechanisms for maintaining the tabs  52 , 54  within the tab pockets  48 , 50  may be used alternatively. The tabs  52 , 54  and tab pockets  48 , 50  enable the replaceable cartridge  14  to be selectively separable from the reusable handle  12 . 
   Referring to  FIGS. 2 and 4 , in a preferred embodiment the razor assembly  10  further includes a cartridge biasing mechanism  58  that biases the replaceable cartridge  14  into a predetermined position. The cartridge biasing mechanism  58  includes a pair of springs  60 ; each disposed within one of the channels  46  in the seat mount  22 . The springs  60  act between the seat mount  22  and the cartridge seat  20 , thereby biasing the cartridge seat  20  and attached replaceable cartridge  14  into a predetermined position at one end of the pivotal travel between the cartridge seat  20  and the seat mount  22 . 
   Referring to  FIGS. 1 ,  2 , and  5 , in a preferred embodiment the razor assembly  10  further includes an ejector  62  for selectively separating the replaceable cartridge  14  from the reusable handle  12 . In the exemplary embodiment shown in  FIGS. 1 ,  2 , and  5 , the ejector  62  includes an ejector housing  64 , a spring  66 , and a spring block  68 . The spring block  68  is received within a pocket  70  disposed within the cartridge seat  20 . The ejector housing  64  includes a slot  72  for receiving a portion of the cartridge seat  20 . The spring  66  acts between the ejector housing  64  and the spring block  68 . The spring block  68  is in contact with a center tab  74  of the replaceable cartridge  14 , thereby biasing the replaceable cartridge  14  and assisting in maintaining the engagement of the detent features (e.g., the raised lip  56 ). In alternative embodiments, the spring block  68  can be fixedly attached to cartridge seat  20 . The present razor assembly  10  embodiment shown in  FIG. 1  further includes a first actuator  76  for actuating the above-described ejector  62 . The first actuator  76  includes a pivotally mounted trigger  78  and spur  80 , a slide  82 , and a slide spring  84 . The first end of the slide  82  is disposed adjacent the pivotally mounted spur  80  and a second end of the slide  82  is disposed adjacent the ejector housing  64 . The slide spring  84  biases the slide  82  into contact with the spur  80  and thereby biases the trigger  78  outwardly. The embodiment of the present razor assembly  10  shown in  FIG. 1  further includes a second actuator  86  for actuating the above-described ejector  62  that can be provided with, or in place of, the above-described first actuator  76 . The second actuator  86  includes a button  88  that is attached to the slide  82 . 
   In the operation of the razor assembly  10 , the user selectively attaches a replaceable cartridge  14  to the reusable handle  12 . Specifically, the replaceable cartridge  14  is fixedly attached to the cartridge seat  20  by inserting the tabs  52 , 54  of the replaceable cartridge  14  into the tab pockets  48 , 50  of the cartridge seat  20 . The detent mechanism on each tab  52 , 54  (e.g., raised lip  56 ) maintains the tab  52 , 54  within the tab pocket  48 ,  50 . The cartridge seat  20  is pivotally attached to the seat mount  22 , and the seat mount  22  is fixedly attached to the elongated member  24  of the handle grip portion  18 . The pivotal attachment between the cartridge seat  20  and the seat mount  22  enables the replaceable cartridge  14  to rotate relative to the handle  12  to accommodate surface contour changes as the razor assembly  10  is stroked across the surface to be shaved. 
   In the exemplary embodiment shown in  FIGS. 1–6 , the replaceable cartridge  14  is biased in a predetermined position by the springs  60  of the cartridge biasing mechanism  58  (see  FIGS. 2 and 4 ). Force applied normal to the shave plane  90  of the replaceable cartridge  14  will oppose the force of the cartridge biasing mechanism  58 . When the normal force is greater than the biasing force, the springs  60  compress and allow the replaceable cartridge  14  to rotate relative to the handle  12 . The biasing force maintains the razor blades  30  of the replaceable cartridge  14  in contact with the surface to be shaved. The magnitude of the biasing force can be altered (e.g., stronger/weaker springs  60 ) to create desirable shaving characteristics for a particular razor assembly  10  and/or application. When the normal force is removed, the springs  60  of cartridge biasing mechanism  58  will bias the replaceable cartridge  14  back into the predetermined position. 
   When the user elects to replace the replaceable cartridge  14  with a new cartridge  14 , the user actuates one of the trigger  78  or the button  88 . Actuation of either the trigger  78  or the button  88  causes the slide  82  to move the ejector housing  64 . Movement of the ejector housing  64 , in turn, dislodges the detent mechanism (e.g., raised lip  56 ) on each table  52 , 54  and causes the replaceable cartridge  14  to be ejected from the tab pockets  48 , 50 . The spring  66  acting between the spring block  68  and the ejector housing  64  assists the ejection of the replaceable cartridge  14 . Once the used replaceable cartridge  14  is ejected, a new replaceable cartridge  14  can be fixedly attached to the cartridge seat  20  in the manner described above; i.e., by inserting the tabs  52 , 54  attached to the replaceable cartridge  14  into the tab pockets  48 , 50  disposed within the cartridge seat  20 . 
   Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the invention. For example, in the Detailed Description above, the pivotal connection between the cartridge seat and the seat mount is described in terms of a preferred arcuate rail and channel arrangement. Alternative pivot mechanisms within the reusable handle may be used alternatively.