Abstract:
A securing device for a spring is provided, the device having a generally hollow spring support having a spring mount having a projection on an inner side of the spring support and configured to support the spring, the device further having a generally annular coupling ring configured to connect to the spring support to secure the spring to the spring support.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     The present application is related to Korean Patent Application Nos. 2002-006335 and 2002-006340, both filed on Feb. 4, 2002, the disclosures of which are expressly incorporated by reference in their entirety.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a securing device for a spring, and more particularly, to a securing device for a spring which allows an operator to perform fixing and assembly operations of the spring in an isolation glove box, and provides a more convenient way for fixing the spring on a spring support.  
         [0004]     2. Description of the Related Art  
         [0005]     Generally, a variety of reciprocating devices, including but not limited to free-piston machines, are often used in a heat regeneration type of refrigerator, including but not limited to Stirling coolers, Gifford-McMahon refrigerators, and the like. A conventional free-piston machine is described in U.S. Pat. No. 6,293,184, which issued to Unger on Sep. 25, 2001, the contents of which are expressly incorporated by reference in its entirety.  
         [0006]     As shown in  FIG. 1 , a reciprocating device  1  includes a driving part  100  for compressing a working gas through linear reciprocating movement of a piston  140  by electromagnetic mutual interaction of a linear motor  130 , a conducting part  200  for absorbing a part of the heat of the gas, which is compressed in high temperature and pressure in the driving part  100 , or conducting the heat to the outside, and a cooling part  300  for transforming the gas into a low temperature state by a thermodynamic cycle while the gas reciprocally moves in a regenerator  330  after an amount of heat is absorbed by the conducting part  200 .  
         [0007]     The driving part  100  includes a tube  120  having a space therein, and is fastened to a frame  110  concentrically arranged with inner/outer conducting parts  210  and  220  respectively, and having a displacer  310 . A linear motor  130  has a stator  130   a  and an armature (magnet sleeve)  130   b , and installed in the inside the shell tube  120 . A piston  140  is fixed to one end of the armature  130   b  of the linear motor  130 , and undergoes the same movement as the armature  130   b  that moves in a linear direction due to the electromagnetic mutual interaction of the linear motor  130 . A cylinder  150  is attached at the center of the inside the frame  110  so that the linear reciprocating movement of the piston  140 , which is inserted therein with to the inner conducting part  210 , can be evenly or uniformly transmitted to the displacer  310 . A planar spring  160  is provided for supporting one end of a displacer rod  320  so that the displacer rod  320  inserted inside the piston  140  and the displacer  310  are threadedly coupled with the rod  320  are concentric/coaxial with the piston  140  and with the inner conducting part  210 . A spring support  170  fixedly supports the planar spring  160 . Reference numeral  130   c  is an inner stator, one of the elements of the linear motor  130 .  
         [0008]     The conducting part  200  includes the inner conducting part  210  oriented toward the frame  110  and concentric to the cylinder  150  and the piston  140 , such that the displacer  310  makes a linear reciprocating movement corresponding to the linear reciprocating movement of the piston  140 . The conducting part  200  further includes an outer conducting part  220  fixed to the external circumferential surface of the inner conducting part  210 .  
         [0009]     The cooling part  300  includes a displacer  310  and a displacer rod  320  moving reciprocally in a linear direction within the range of elastic deformation of the planar spring  160 , which is fixed in the inside the inner conducting part  210  and supports one end of the displacer rod  320 . A regenerator  330  is installed in the displacer  310  and stores the heat of the gas in a high temperature and pressure state after being moved by the piston  140  and being compressed into the displacer  310 , and after the gas is expanded, transmitting the stored heat to the expanded gas in a low temperature state, thereby compensating for the temperature of the gas changing back to a low temperature. A displacer housing  340  accommodates the displacer  310  therein, and has a cooling side part  350  fixed to one end of the cylinder. The cooling side part  350  exchanges heat with the outside (i.e. exterior) so that the gas passing through the regenerator  330  installed inside the displacer  310  is expanded and returned to a low temperature.  
         [0010]     Since the reciprocating device  1  cannot use oil for lubrication, it requires precise centering during assembly, and further requires a device for preventing eccentricity during operation. In other words, since the reciprocating device breaks down if weak friction surfaces are abraded, significant attention and precise assembly is required.  
         [0011]     For this purpose, gas bearings are used in sliding portions. However, since a supporting force of the gas bearing is weak, centering and eccentricity prevention are always required.  
         [0012]     The planar spring, also known as a “flexure” spring, is frequently used as an eccentricity-preventing device. By screwing the planar spring  160  to the spring support  170  through a plurality of fixing holes formed at an edge of the planar spring  160  with the displacer rod  320  inserted into the middle of the planar spring  160 , the planar spring  160  is fixed to the spring support  170 . In this way, a screw fixation method is mainly used for the support of the planar spring.  
         [0013]     However, in reality, an operator has to wear thick rubber gloves in order to perform an assembly process in the isolation glove box filled with nitrogen. Under such a condition, it is very difficult to assemble small screws, as the operators tactile sensation is reduced by the thick rubber gloves.  
         [0014]     Therefore, it is a problem that a fixing operation of the planar spring  160  to the planar spring support by using small screws is troublesome and inconvenient, resulting in serious deterioration of work efficiency.  
       SUMMARY OF THE INVENTION  
       [0015]     Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and a feature of the present invention provides a securing device for a planar spring for fixing a displacer, which is capable of allowing an operator wearing rubber gloves to perform fixing and assembly operations of the planar spring in a glove box and fixing the planar spring at a spring support simply by fixing the planar spring into the spring support by a threaded combination of the spring support in which a spring mount is provided and a covering member (instead of the conventional screw fixation method by which the planar spring is fixed to the spring support by use of screws).  
         [0016]     Another feature of the present invention provides a fixing device for a spring, the device being capable of allowing an operator wearing rubber gloves to perform simple fixing and assembly operations of the planar spring in a glove box and fixing the planar spring at a spring support in which a spring mount is provided at maximal combination force of the spring support and a covering member in which fixation holes into which fixing tools are inserted are formed, by using the fixing tools.  
         [0017]     Yet another feature of the present invention provides a securing device for a spring for fixing a displacer, which is capable of improving work efficiency through reduction of the number of assembly steps for the planar spring and the spring support and hence reducing work time.  
         [0018]     The present invention provides a fixing device for a spring, having a generally hollow spring support including a spring mount having a projection on an inner side of the spring support and configured to support the planar spring. The fixing device further has a generally hollow covering member configured to connect to the spring support to affix the planar spring to the spring support. The spring support may have a first inner diameter and a second inner diameter, and the spring mount may radially inwardly project at a region between the first and second inner diameters.  
         [0019]     According to a feature of the invention, first threads may be formed on an inner periphery of the spring mount of the spring support, and second threads may be formed on an outer periphery of the covering member, the first and second threads configured to threadedly engage each other.  
         [0020]     Additionally, the covering member may be a synthetic resin member and may be configured to at least one of press and fix a periphery of the spring via a generally ring-shaped nut.  
         [0021]     A securing device for a spring according to another aspect of the invention has a generally hollow spring support including a spring mount having a projection on an inner side of the spring support and configured to support the spring. The fixing device further has a generally hollow covering member configured to connect to the spring support to affix the spring to the spring support, and a plurality of fixation holes penetratingly formed through the covering member, the plurality of fixation holes configured to accept a respective plurality of fixation tools.  
         [0022]     Additionally the plurality of fixation holes may be at an interval of one of approximately 90° and 180° on the covering member.  
         [0023]     A fixing device according to still another aspect of the invention includes a generally hollow spring support including a spring mount having a projection on an inner side of the spring support and configured to support the spring. Also provided is a generally hollow covering member configured to connect to the spring support to affix the spring to the spring support, and a plurality of threaded holes in the covering member.  
         [0024]     A securing device for a spring according to a further aspect of the invention has a generally hollow spring support including a spring mount having a projection on an inner side of the spring support and configured to support the spring, a generally hollow covering member configured to connect to the spring support to affix the spring to the spring support, and a plurality of grooves in the covering member.  
         [0025]     Additionally, the plurality of grooves may be at an interval of one of approximately 90° and 180° on the covering member.  
         [0026]     A securing device for a spring according to yet a further aspect of the invention has a generally hollow spring support including a spring mount having a projection on an inner side of the spring support and configured to support the spring, a generally hollow covering member configured to connect to the spring support for fixing the spring to the spring support, and a plurality of projections in the covering member.  
         [0027]     Also, the plurality of projections may be at an interval of one of approximately 90° and 180° on the covering member.  
         [0028]     A method of the present invention for fixing a spring to a reciprocating device, includes inserting a spring into a generally hollow spring support such that a projection of the spring support supports the spring, and connecting a generally hollow connecting member to the spring support such that the spring is secured and sandwiched between the connecting member and the projection.  
         [0029]     Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]     The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of certain embodiments of the present invention, in which like numerals represent like elements throughout the several views of the drawings, and wherein:  
         [0031]      FIG. 1  is a schematic view showing a construction of a conventional reciprocating device;  
         [0032]      FIG. 2A  is a plan view of a conventional spring for use in the conventional reciprocating device;  
         [0033]      FIG. 2B  is a sectional view showing how a spring is fixed at a spring support by a fixing device in  FIG. 1 ;  
         [0034]      FIG. 3  is an exploded sectional view of a securing device for a spring according to a first embodiment of the present invention;  
         [0035]      FIG. 4  is a combined sectional view of a securing device for a spring according to the first embodiment of the present invention;  
         [0036]      FIG. 5A  is a plan view of a covering member according to a second embodiment of the present invention;  
         [0037]      FIG. 5B  is an exploded sectional view of a securing device for a spring according to the second embodiment of the present invention;  
         [0038]      FIG. 6  is a sectional view of a securing device for a spring according to the second embodiment of the present invention;  
         [0039]      FIG. 7A  is a plan view of a covering member according to a third embodiment of the present invention;  
         [0040]      FIG. 7B  is a sectional view of a securing device for a spring according to the third embodiment of the present invention, taken along the line A-A of  FIG. 7A ;  
         [0041]      FIG. 8A  is a plan view of a covering member according to a fourth embodiment of the present invention;  
         [0042]      FIG. 8B  is a sectional view of a securing device for a spring according to the fourth embodiment of the present invention, taken along the line B-B of  FIG. 8A ;  
         [0043]      FIG. 9A  is a plan view of a covering member according to a fifth embodiment of the present invention;  
         [0044]      FIG. 9B  is a sectional view of a securing device for a spring according to the fifth embodiment of the present invention, taken along the line C-C of  FIG. 9A ; and  
         [0045]      FIG. 10  is an exploded sectional view of a securing device for a spring according to a sixth embodiment of the present invention 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0046]     The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.  
         [0047]      FIG. 3  is an exploded sectional view of a securing device for a spring according to a first embodiment of the present invention, and  FIG. 4  is a combined (i.e., assembled) sectional view of a securing device for a spring according to the first embodiment of the present invention. For example, while some of the figures may illustrate a free-piston Stirling engine, it is readily appreciable by those skilled in the art that the present invention is applicable to a wide variety of reciprocating and/or oscillating devices. Additionally, while some of the figures illustrate a planar spring, it is readily appreciable by those skilled in the art that the present invention is applicable to fix a wide variety of springs.  
         [0048]     As shown in  FIGS. 3 and 4 , a fixing device  400  of a spring for fixing a displacer according to a first embodiment of the present invention is for fixing the spring  160  to the spring support  430  by combining forces between the spring support  430  and the hollow covering member (coupling ring)  460 , connecting the hollow covering member  460  with the spring support  430  with the spring  160  mounted on a spring mount  440  having a round projecting shape (as opposed instead of the conventional troublesome and inconvenient fixing method for fixing the spring  160  at the spring support  170  using small screws or bolts). Accordingly, the combination of the spring support  430  and the covering member  460  is achieved by fastening of a female screw  450  formed on an inner periphery of the spring mount  440  of the spring support  430  with a male screw  470  formed on an outer periphery of the covering member  460 .  
         [0049]     In the present invention, the spring support  430  as one of the elements of the fixing device  400  of the spring, has a hollow shape and has one portion at which the spring mount  440 , having a round projecting shape in which the spring  160  is mounted, is formed and extends for a predetermined depth from an upper end of the member  430 , and has another portion that is slightly wider than a diameter of the spring mount  440  such that the spring mount  440  is formed thereby. Also, the female screw  450  for fastening the covering member  460  with the spring mount  440  is formed on the inner periphery of the spring mount  440 .  
         [0050]     In addition, the covering member  460  is also formed to have a hollow shape such that a displacer rod (not shown) is fixed at the middle of the spring  160  mounted on the spring mount  440  of the spring support  430 . Also, the male screw  470  is formed on the outer periphery of the covering member  460  for threadedly engaging the female screw  450  formed on the spring mount  440  of the spring support  430 .  
         [0051]      FIG. 5A  is a plan view of a covering member according to a second embodiment of the present invention,  FIG. 5B  is an exploded sectional view of a securing device for a spring according to the second embodiment of the present invention, and  FIG. 6  is a combined (i.e., assembly) sectional view of a securing device for a spring according to the second embodiment of the present invention.  
         [0052]     As shown in  FIGS. 5A, 5B  and  6 , a fixing device  500  of a spring for fixing a displacer according to the second embodiment of the present invention is for fixing the spring  160  to spring support  530  by a combining force between the spring support  530  and hollow covering member (coupling ring)  560  by coupling the hollow covering member  560 , having a plurality of fixation holes  580  into which fixation tools (not shown) are inserted, to the spring support  530 , having the spring  160  mounted on its spring mount  540 , having a round projection shape (instead of the conventional troublesome and inconvenient prior art fixing method for fixing the spring  160  at the spring support  170  using small screws or bolts). Accordingly, fastening of the spring support  530  and the covering member  560  is achieved by a spiral (i.e., threaded) joining of a female screw  550  formed on an inner periphery of the spring mount  540  of the spring support  530  and a male screw  570  formed on an outer periphery of the covering member  560 .  
         [0053]     In the present invention, spring support  530  as one element of the fixing device  500  of the spring has a hollow shape and has one portion at which the spring mount  540  having a round projection shape on which the spring  160  is mounted and extends for a predetermined depth from an upper end of the spring support  530 , and has another portion that is slightly larger than a diameter of the spring mount  540  such that the spring mount  540  is formed. Also, the female screw  550  for fastening the covering member  560  with the spring mount  540  is formed on the inner periphery of the spring mount  540 .  
         [0054]     In addition, the covering member  560  is also formed to have a hollow shape such that a displacer rod (not shown) is fixed at the middle of the spring  160  mounted on the spring mount  540  of the spring support  530 . Also, the male screw  570  is formed on the outer periphery of the covering member  560  for threadedly engaging the female screw  550  formed on the spring mount  540  of the spring support  530 .  
         [0055]     In addition, in order to increase the connecting forces between the spring support  530  and the covering member  560 , the plurality of fixation holes  580  each having a predetermined diameter, into which the fixation tools are inserted, are penetratingly formed through the covering member  560 . Specifically, each fixation tool used in each embodiment has protrusions/voids configured to engage complimentary voids/protrusions of the covering member  560 . As illustrated, the fixation holes  580  are formed at an interval of approximately 90° or 180° about the covering member  560 , although other intervals are within the scope of the present invention. For example, for a covering member  560  having fixation holes  580  formed at 90° about the covering member, a corresponding fixation tool would have protrusions formed at 90° on the covering member. Thus, with such a configuration, a fixation tool can securely engage the covering member  560 , and an operator performing fixing or assembly operations can apply a sufficient amount of torque to the covering member to secure it to the spring support  530 .  
         [0056]     Hereinafter, only the difference between the constructions of fixing devices of springs for fixing (or securing) displacers according to the third, fourth, and fifth embodiments of the present invention and the securing device for the spring according to the second embodiment of the present invention will be described.  
         [0057]      FIG. 7A  is a plan view of a covering member according to a third embodiment of the present invention and  FIG. 7B  is a sectional view of a securing device for a spring according to the third embodiment of the present invention, taken along the line A-A of  FIG. 7A .  
         [0058]     As shown in  FIGS. 7A and 7B , the securing device for the spring according to the third embodiment of the present invention has a plurality of female screw holes  780  (instead of the plurality of the fixation holes  580  having a predetermined diameter, into which the fixation tools are inserted). The plurality of female screw holes  780  are penetratingly formed through covering member  760  in order to increase the connecting force between the spring support  430 ,  530  and the covering member. Specifically, a fixation tool (not shown) having a complimentary and corresponding set of male screws is configured to penetratingly engage the female screw holes  780  of the covering member  760  so that an operator performing fixing or assembly operations can apply a sufficient amount of torque to the covering member to secure it to the spring support  430 , 530 .  
         [0059]      FIG. 8A  is a plan view of a covering member according to a fourth embodiment of the present invention, and  FIG. 8B  is a sectional view of a securing device for a spring according to the fourth embodiment of the present invention, taken along the line B-B of  FIG. 8A .  
         [0060]     As shown in  FIGS. 8A and 8B , the securing device for the spring according to the fourth embodiment of the present invention has a plurality of grooves  880  (instead of a plurality of the fixation holes  580  having the specific diameter, into which the fixation tools are inserted). The plurality of combination grooves  880  are formed on covering member  860  in order to increase the connecting force between the spring support  430 ,  530  and the covering member  860 . Specifically, a fixation tool (not shown) having a complimentary and corresponding set of protrusions is configured to penetratingly engage the grooves  880  of the covering member  860  so that an operator performing fixing or assembly operations can apply a sufficient amount of torque to the covering member to secure it to the spring support  430 , 530 .  
         [0061]      FIG. 9A  is a plan view of a covering member according to a fifth embodiment of the present invention, and  FIG. 9B  is a sectional view of a securing device for a spring according to the fifth embodiment of the present invention, taken along the line C-C of  FIG. 9A   
         [0062]     As shown in  FIGS. 9A and 9B , the securing device for the spring according to the fifth embodiment of the present invention has a plurality of combination projectors  980  (instead of a plurality of the fixation holes  580  having the specific diameter, into which the fixation tools are inserted). The plurality of combination projections  980  are formed on covering member  960  in order to increase the connecting force between the spring support  430 ,  530  and the covering member  960 . Specifically, a fixation tool (not shown) having a complimentary and corresponding set of channels is configured to penetratingly engage the projections  980  of the covering member  960  so that an operator performing fixing or assembly operations can apply a sufficient amount of torque to the covering member to secure it to the spring support  430 , 530 .  
         [0063]     Hereinafter, as still another embodiment (a sixth embodiment) of the present invention, a securing device for a spring in which the screw configuration in the aforementioned embodiments is eliminated and the entire periphery of the spring is pressed and fixed by a nut of a ring shape will be described.  
         [0064]      FIG. 10  is an exploded sectional view of a securing device for a spring according to the sixth embodiment of the present invention.  
         [0065]     As shown in  FIG. 10 , the securing device for the spring according to the sixth embodiment of the present invention includes a spring support  1030  having a spring mount  1040  with screws ( 450  and  550  in  FIGS. 4, 5A  and  5 B) eliminated such that the spring  160  is pressingly fixed in a manner other than the threaded combining systems of the spring support ( 430  and  530  in  FIGS. 4, 5A  and  5 B) and the covering member (coupling ring) ( 460 ,  560 ,  760 ,  860  and  960  in FIGS.  4  to  9 B), in that a hollow covering member  1060  made from synthetic resin having elasticity such that specific weight or pressure is applied to the spring support  1030 .  
         [0066]     This configuration provides a combination construction of a ring nut, by which an operator wearing a thick glove can perform an assembling operation. In other words, the screw configuration is eliminated and the entire periphery of the spring is pressed and fixed by the ring-shaped nut.  
         [0067]     In contrast to the fixing devices of the springs according to the second, third, fourth and fifth embodiments of the present invention, the female screws formed on the inner periphery of the spring mount of the spring support and the male screws formed on the outer periphery of the covering member can be eliminated. In other words, the screw configuration is eliminated and the entire periphery of the spring is pressed and fixed by the ring-shaped nut.  
         [0068]     It is of course understood that various features of the different embodiments can be combined within the scope of the present invention.  
         [0069]     Now, an operation of the securing device for the spring for fixing the displacer according to the present invention will be described in terms of a combination process of the spring support (in which the spring is mounted on the spring mount of the spring support) and the covering member.  
         [0070]     As shown in  FIGS. 3 and 4 , in order to fix the spring  160  elastically deformed by the linear reciprocal motion of the displacer, which contains the reproducer, and the displacer rod at the spring support  430 , the spring into which the displacer rod is inserted is first mounted on the spring mount  440  of the spring support  430 . Subsequently, by the male screw  470  of the hollow covering member  460  is threadedly engaged with the female screw  450  of the spring mount of the spring support  430  after the position of the displacer rod is adjusted, the spring  160  is fixed onto the spring support  430 .  
         [0071]     In addition, as shown in  FIGS. 5A, 5B ,  6 A and  6 B, in order to increase the combining (i.e., holding) force between the spring support  530  and the covering member  560 , fixation tools (not shown) may be inserted into the plurality of fixation holes  580  penetratingly formed through the covering member  560 . Subsequently, by rotating the fixation tools in a threading direction, the spring support  530  and the covering member  560  are combined to each other with maximal combination force. At that time, as the bottom of the covering member  560  presses the entire periphery of the spring  160  mounted on the spring mount  540 , the spring  160  is fixed to the spring support  530 .  
         [0072]     As described above, an advantage of the present invention is that an operator wearing a rubber glove can perform fixation and assembly operations of the spring in a glove box and fix the spring at the spring support more easily, by fixing the spring to the spring support by fastening the spring support in which the spring mount is provided and the covering member (instead of the conventional screw fixation method in which the spring is fixed to the spring support using screws).  
         [0073]     In addition, by rotating the fixation tools inserted into the fixation holes in a threading direction so that the spring support and the covering member are combined to each other with maximal combining force, the spring can be simply fixed to the spring support.  
         [0074]     Therefore, the present invention improves work efficiency through a reduction in the number of assembly steps for the spring and the spring support, thereby reducing the working time.  
         [0075]     It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to certain embodiments, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.