Abstract:
A method and apparatus for making a shaped-spring assembly. The method and apparatus utilizes a multifunctional tool or apparatus which permits the forming, storing and loading of shaped springs into a shaped spring cavity so as to form a shaped-spring assembly. The tool of the present invention permits the formation and storage of the shaped springs without fatiguing the spring, and also permits the loading of the shaped spring into a shaped-spring cavity in a manner that does not result in too large or too low of spring force for the shaped spring assembly.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an apparatus and method for making a shaped-spring assembly for use in a magnetic head-to-media backer device. More specifically, the present invention relates to an apparatus and method, wherein a multifunctional tool or apparatus can be used to form a shaped spring from a spring blank, store the shaped spring and load the shaped spring into a shaped spring cavity to form a shaped spring assembly.  
       BACKGROUND OF THE INVENTION  
       [0002]     Shaped-spring assemblies have been used in a number of electrical and mechanical devices such as cameras, tape decks, sound recording devices, and automated materials handling machinery. These shaped-spring assemblies are commonly called bubble-spring assemblies and are employed in situations that require a constant load with the ability to accommodate large spacial displacements. A typical bubble-spring assembly provides a restraining force against a moving piece of a magnetic section of a film, so that the film is held against a recording head under constant pressure.  
         [0003]     A bubble-spring assembly typically includes a cavity that comprises a block and the bubble spring. The cavity includes a shaped-hollow cavity formed through the block and the bubble spring is typically small and thin. Due to the size of the spring, delicate handling of the spring is required. The bubble spring is positioned within the cavity to form a convex or arched portion that extends beyond the dimension of the cavity block. In this manner, the bubble spring is placed under tension and will thereby provide a spring force against an article, such as film, that has displaced the spring into the cavity. Prior to shaping and insertion into the cavity, the bubble spring is a flat elongated piece of thin material, typically metal, and commonly referred to as a spring blank. This type of bubble spring assembly is disclosed in, for example, U.S. Pat. Nos. 5,274,522 and 5,531,008.  
         [0004]     As an example, in a conventional APS filmstrip, there is a magnetic layer that provides a way to read and/or write data. The above-mentioned U.S. Pat. No. 5,274,522 as noted above, discloses a bubble spring load pad that is a film backer pad used for urging the film base to a magnetic head. This backer pad (also known as a bubble spring assembly) includes a cavity and the bubble spring. After extended use of the assembly including the bubble spring, it has been found that the spring needs to be routinely replaced. This is due to the constant urging of the bubble spring against the magnetic layer of the film. Due to cost, it is not economically feasible to replace both the cavity and the bubble spring each time the spring needs to be replaced. It is preferred to use the existing cavity and install a new spring. However, as noted above, the springs tend to be small and thin, and thus very difficult to accurately replace within a small cavity without adversely affecting the spring characteristics of the spring. Also, in reloading bubble springs within a cavity, manufacturers and/or consumers may use springs from manufacturers that may provide poor spring performance due to inferior material and/or manufacturing methods.  
         [0005]     A method of replacing a spring as disclosed in the above-mentioned U.S. Pat. No. 5,531,008 is complex and has a fair amount of cost and usage difficulty associated with it. The apparatus as disclosed in U.S. Pat. No. 5,531,008 also only supplies one spring at a time. Further, the method of spring installation as disclosed in the U.S. Pat. No. 5,531,008 causes the leading half of the spring to be fatigued during spring installation by the way the leading edge of the spring gets forced into, then around, a tight radius. This causes the leading half of the spring to be fatigued. This may cause the spring load to be lower in head load after spring installation than is desired. That is, the film has what is called an anticlastic effect (edge curl) under the edge of the film on/or close to the magnetic head track signal location. Under certain situations such as lower humidity and/or core set film, a lower gram load could limit the springs ability to provide the needed force on the outside track location to provide a high enough force to obtain consistent read/write signal processing.  
         [0006]     The loading or replacement of springs needs to be done in a manner which does not result in too large or too low of a spring force, since a large spring force would tend to damage the film or article that the spring rides against, and a low spring force would not provide enough of a force to urge the spring against, for example, a magnetic head.  
         [0007]     U.S. Pat. Nos. 6,470,572 and 6,594,903 to Eastman Kodak Company disclose arrangements for forming shaped spring assemblies wherein the loading or replacement of spring can be done in a manner that does not result in too large or too low of a spring force. However, the arrangements of U.S. Pat. Nos. 6,420,572 and 6,594,903 require a first tool for shaping a spring blank into a shaped spring, and a second tool for storing the shaped spring and loading the stored shaped spring into a cavity to form a shaped spring assembly. Therefore, U.S. Pat. Nos. 6,470,572 and 6,594,903 disclose the use of separate tools, one tool for forming the shaped springs and a second tool for storing the shaped springs and loading the shaped springs into a shaped spring cavity. Further, the arrangement of these two patents require the cooperation of the two tools when the shaped springs are to be transferred or loaded from the first tool to the second tool which adds labor and requires the association of the first tool with the second tool.  
         [0008]     What is needed is a multifunctional tool or apparatus that can form shaped springs from spring blanks, can store the shaped springs, and can load the shaped springs into a cavity without requiring the cooperation and/or use of separate tools. What is further needed is a multi-functional tool or apparatus as noted above which can load or replace springs in a manner which does not result in too large or too low of a spring force, since a large spring force would tend to damage the film or article that the spring rides against, and a low spring force would not provide enough of a force to urge the spring against, for example, a magnetic head.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention provides for an improved method and apparatus for making a bubble spring (hereinafter referred to as a shaped-spring) assembly. The method and apparatus of the present invention utilizes a novel multifunctional tool or apparatus which is adapted to form a shaped spring from a spring blank, store the shaped spring and load the shaped spring into a shaped spring cavity to form a shaped spring assembly.  
         [0010]     The present invention further provides for a mechanism and method that reduces or eliminates the necessity of installing undesired springs from manufacturers that may use unapproved springs which can cause poor performance. This is because the present invention provides for a magazine that can be pre-loaded at a controlled location.  
         [0011]     The present invention therefore relates to a method of shaping a spring blank to form a shaped spring which comprises the steps of placing a spring blank at an opening of an elongated slot; placing a spacer member adjacent to the spring blank; and pushing the spacer member against the spring blank to urge both the spring blank and the spacer member through the opening and into the elongated slot, and cause the spring blank to wrap around an outer surface of the spacer member, wherein the spring blank conforms to a shape of the outer surface of the spacer member to form a shaped spring.  
         [0012]     The present invention further relates to a spring shaping apparatus adapted to form shaped springs, store the formed shaped springs and load the formed shaped springs into a shaped spring cavity to form a shaped spring assembly. The apparatus comprises a base member having a longitudinally extending slot which is closed at a first end and open at a second end, with the slot being adapted to hold a plurality of shaped springs therein with a plurality of spacer members being provided between the shaped springs; and a platform extending from the opening at the second end of the slot. The platform is sized to hold a spring blank and a spacer member thereon in a position which permits a user to push a surface of the spacer member in a first direction against the spring blank to urge the spring blank and the spacer member into the slot, such that the spring blank wraps around the surface of the spacer member and forms a shaped spring in the slot. The platform is further adapted to hold a shaped spring cavity in a loading position on the platform, such that a shaped spring cavity can be placed in the loading position on the platform when a desired number of shaped springs with spacer members there-between are inserted into the slot, to permit a loading of a shaped spring from the slot into the cavity to form a shaped spring assembly.  
         [0013]     The present invention further relates to a method of forming, storing, and loading shaped springs to form a shaped spring assembly which comprises the steps of: (a) placing a spring blank on a platform of a base member and adjacent to an opening of an elongated slot of the base member, with a length of the spring blank being greater than a width of the opening; (b) placing a spacer member on the platform and adjacent to the spring blank, such that the opening is on a first side of the spring blank and the spacer member is on a second side of the spring blank which is opposite to the first side; (c) pushing the spacer member in a first direction against the second side of the spring blank to urge both the spring blank and the spacer member through the opening and into the slot to cause the spring blank to wrap around an outer surface of the spacer member, wherein the spring blank conforms to a shape of the outer surface of the spacer member to form a shaped spring; (d) repeating said steps (a) to (c) until a desired number of shaped springs and spacer members are alternately positioned in a row in said elongated slot; (e) pushing a first spacer member in the slot which is closest to the opening in a second direction that is opposite to the first direction and out of the slot; (f) placing an empty shaped spring cavity on the platform of the base member; and (g) pushing a next spacer member in the slot in the second direction opposite to the first direction, to push an adjacent shaped spring toward the cavity and load the shaped spring into the cavity to form a shaped spring assembly.  
         [0014]     The present invention further relates to spring shaping tool adapted to form shaped springs and load the formed shaped springs into a shaped spring cavity to form a shaped spring assembly. The tool comprises a base member having a slot which is adapted to hold a plurality of shaped springs therein with a plurality of spacer members being provided between the shaped springs; and a platform extending from the base member. The platform is sized to hold a spring blank and a spacer member thereon in a position which permits a user to push a surface of the spacer member in a first direction against the spring blank, so that the spring blank and the spacer member are urged into the slot to cause the spring blank to wrap around the surface of the spacer member and form a shaped spring. The platform is further adapted to hold a shaped spring cavity to permit a loading of a shaped spring from the slot into the cavity when a desired number of shaped springs are inserted into the slot, to form a shaped spring assembly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is an isolated perspective view of a shaped-spring assembly made in accordance with the present invention;  
         [0016]      FIG. 2  is a perspective view of a multifunctional tool or apparatus used to form, store and load a shaped spring in accordance with the present invention;  
         [0017]      FIG. 3  is a view of the tool or apparatus of  FIG. 2  having a spring blank to be shaped provided thereon;  
         [0018]      FIG. 4  is a view of a portion of the tool or apparatus of  FIG. 2 , wherein a spacer member has been pushed against the spring blank to form a shaped spring;  
         [0019]      FIG. 5  is a view of the tool or apparatus of  FIG. 2 , wherein multiple spacer members having shaped springs formed and provided therebetween are shown being pushed into the elongated slot of the tool or apparatus;  
         [0020]      FIG. 6  is a view of the tool or apparatus of  FIG. 2 , wherein a plurality of shaped springs with spacer members therebetween are loaded and stored in the tool or apparatus;  
         [0021]      FIG. 7  is a view of the tool or apparatus of  FIG. 2 , wherein a first spacer member is moved in preparation for the forming of a shaped spring assembly;  
         [0022]      FIG. 8  is a view of the tool or apparatus of  FIG. 2 , wherein a shaped spring cavity is provide in a loading position on the tool or apparatus; and  
         [0023]      FIG. 9  is a view of the tool or apparatus of  FIG. 2 , wherein a shaped spring is loaded onto a cavity to form a shaped spring assembly. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     Referring now to the drawings, wherein like reference numerals represent identical or corresponding parts through the several views,  FIG. 1  illustrates a shaped-spring assembly  5  that is made in accordance with the apparatus and method of the present invention. As illustrated in  FIG. 1 , shaped-spring assembly  5  includes a shaped-spring cavity  7  which generally comprises end sections  9   a ,  9   b  and a middle flat head section  11 . The combination of end section  9   a  and one side of flat head section  11  defines a receiving section  15   a , while end section  9   b  and the opposite side of flat head section  11  defines a further receiving section  15   b . Shaped spring assembly  5  further includes a spring blank which is curved to form a shaped spring  17 . More specifically, shaped spring  17  is curved or arched so that the arched ends are held within receiving sections  15   a ,  15   b  such that spring  17  exhibits spring-like characteristics. Thus, spring  17  is placed under tension within shaped-spring cavity  7 , so as to provide a spring force against an article, such as, the film of a recording device or the magnetic layer of photosensitive film within a camera.  
         [0025]     It is noted that the spring blank which forms shaped spring  17  is a delicate and fragile item. A typical spring blank has a thickness of approximately 0.0015 inches (0.0381 mm), a length of less than an inch (2.54 cm), and a width not exceeding 0.125 inches (0.317 cm). The spring blank is further commonly formed from stainless steel. In many applications, the spring blank includes a highly burnished surface that will contact super sensitive material. In an environment in which the shaped spring  17  is to contact, for example, a magnetic layer on film, it is desirable that the shaped spring not only have a predictable stress strain history resulting from the shaping process, but also retain the qualities associated with the burnished surface by avoiding even minor or hair line scratches. Thus, a precise and controlled method and apparatus are necessary so as to properly load a spring blank into shaped-spring cavity  7  to form shaped spring  17  and thereby form shaped spring assembly  5 .  
         [0026]      FIG. 2  illustrates a multifunctional spring shaping tool or apparatus  20  in accordance with the present invention. Spring shaping tool or apparatus  20  is adapted to form shaped springs; store the formed shaped springs and load the formed shaped springs into a shaped spring cavity. As illustrated in  FIG. 2 , spring shaping tool  20  includes a base member  22  which can include a first member  22   a  and a second member  22   b  provided thereon. Tool  20  further includes an elongated slot  24  that comprises a closed end  24   a  and an open end  24   b . Open end  24   b  defines an opening into slot  24 . As also illustrated in  FIG. 2 , tool  20  includes a platform  26  which includes positioning or locating pin or members  28   a  and  28   b.    
         [0027]     With reference to  FIG. 3 , a method for shaping, storing and loading shaped springs will be described.  FIG. 3  illustrates a portion of tool  20  and shows a spring blank  30   a  provided on platform  26 . Spring blank  30   a  generally has a length which is greater than a width of opening  24   b  or slot  24 . The particulars of the spring blank are described above. To illustrate the shaping or conversion of spring blank  30   a  into a shaped spring, reference is made to  FIG. 4 , which illustrates a spacer member  32   a  provided on platform  26  and adapted to be pushed in direction  50  so as to abut against spring blank  30   a . This causes a surface of spacer member  32   a , and specifically a front outer surface of spacer member  32   a  which faces a first side of spring blank  30   a  to abut against spring blank  30   a . Spacer member  32   a  preferably includes a curved outer surface  75   a  (see  FIG. 7 ) which conforms to a desired shape of the spring, as well as a second curved surface  75   b  on an opposing side which conforms to the shape of the spring provided adjacent to this surface  75   b  of the spacer member. Surface  75   b  defines an inwardly directed curve on the spacer member. This permits an effective positioning of spacer members and springs in a row within tool  20  and specifically within elongate slot  24  as shown in  FIGS. 6, 7  and  8 . It is noted that the opposite or second side of spring blank  30   a  faces opening  24   b  of slot  24 . Given the size relationship between slot  24  and spring blank  30   a , the pushing of spacer member  32   a  against the side of spring blank  30   a  further causes spring blank  30   a  to wrap around the outer surface of spacer member  32   a , as spacer member  32   a  and spring blank  30   a  are inserted through opening  24   b  and into elongate slot  24  as illustrated in  FIG. 4 . Therefore, as shown in  FIG. 4 , a shaped spring  30   a ′ is formed when spring blank  30   a  wraps around spacer member  32   a . To push spacer member  32   a  against spring blank  30   a , a user simply has to press his/her finger against the back surface of spacer member  32   a , or the user can use a tool such as a small rod, bar or punch to move spacer member  32   a  and spring blank  30   a  in direction  50  and into elongate slot  24 .  
         [0028]     As illustrated in  FIG. 5 , tool  20  of the present invention is effective to store a plurality of spring blanks with spacer members provided therebetween. That is, as shown in  FIG. 5 a  user can place a further spring blank on platform  26  and push a further spacer member  32   b  in direction  50  so as to provide for shaped spring  30   b ′; and place a still further spring blank on platform  26  and push a further spacer member  32   c  to provide for shaped spring  30   c ′. A user continues this process until the desired number of shaped springs and spacer members are provided in elongate slot  24  or the elongate slot is substantially full of shaped springs and spacer members as illustrated in  FIG. 6 .  
         [0029]     In the embodiment of  FIG. 6 , shaped springs  30   a ′,  30   b ′,  30   c ′, . . .  30   k ′ and . . .  30   l ′, and spacer members  32   a ,  32   b ,  32   c , . . .  32   k  and . . .  32   l ′ disposed respectively therebetween are provided in slot  24 . In this way, tool  20  is effective to hold a desired number of shaped springs therein to be used to form shaped springs assemblies when needed.  
         [0030]     For the purpose of replacing or forming a shaped spring assembly, reference is made to  FIGS. 7-9 . As shown in  FIG. 7 , in order to form a shaped spring assembly a spacer member closest to opening  24   b  and without a shaped spring on it backside or surface  75   b  is first moved in direction  60 . In the embodiment of  FIG. 7 , spacer member  32   l ′ is removed. Spacer member  32   l ′ can be removed by inserting a user&#39;s finger into slot  24  and moving spacer member  32   n ′ out of slot  24  or in a preferred manner, inserting a rod  40  as shown in  FIG. 9  into a hole or opening  70  of spacer member  32   l′.    
         [0031]     As shown in  FIGS. 8 and 9 , after spacer member  32   l ′ is removed a shaped spring  30   l ′ will be exposed. A user thereafter places a cavity  7  on platform  26 . As illustrated in  FIG. 1 , in a preferred embodiment, cavity  7  can include openings or holes  64  which cooperate with locating pins  28   a ,  28   b  on platform  26  and permit the positioning of cavity  7  in a locating position on platform  26  ( FIG. 8 ). Thereafter, shaped spring  30   l ′ is moved by inserting rod or bar-like member  40  into hole  70  of spacer member  32   k  and moving the same in direction  60  against shaped spring  30   l ′ ( FIG. 9 ). This causes shaped spring  30   l ′ to move in direction  60  so that the ends of shaped spring  30   l ′ are inserted into receiving sections  15   a  and  15   b  of cavity  7 . Therefore, a shaped spring assembly which is composed of cavity  7  and shaped spring  30   l ′ is formed. If desired, a user can form additional shaped spring assemblies by pushing the next spacer member (i.e. spacer member  32   k ) out of slot  24 ; placing a further cavity on platform  26 ; and pushing the next shaped spring  32   k ′ into the cavity to form a further shaped spring assembly.  
         [0032]     Although the present invention describes manually pushing the spacer members in directions  50  and  60  by way of a user&#39;s finger or a rod-like member, the present invention is not limited thereto. It is recognized that the present invention can be automated by providing for an automatic-type system which can be controlled to insert a rod or a rod-like member into opening  70  so as to push the appropriate spacer member in the desired direction. Also, other types of devices for pushing, sliding, pulling or moving an article, such as the spacer member, along the slot can also be utilized.  
         [0033]     Therefore, the present invention provides for a multifunctional tool or apparatus which permits the forming, storing and loading of shaped springs and facilitates the shaping of springs so as to form a spring-shaped assembly.  
         [0034]     The present invention further provides for an improved forming, storing and loading arrangement that facilitates the conversion of spring blanks into shaped springs.  
         [0035]     With the apparatus and method of the present invention, it is possible to load empty shaped spring cavities at a controlled location, and it is also possible to convert spring blanks into shaped springs, while maintaining a predictable shaped spring history resulting from the shaping processing.  
         [0036]     The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.