Abstract:
The present invention provides a silencer profile for a roll container which can be retro-fitted and which eliminates noise resulting from metal frame sections of the roll container making contact. The novel silencer may include an engaging portion which has an interior surface configured to engage to a profile of the roll container in an at least partly enclosing manner. The engaging portion also has an exterior surface that opposes the interior surface. The silencer also includes a compression portion formed on the exterior surface of the engaging portion for receiving external impacts. The compression portion features a relieved profile for extending the compression length of the compression portion. The compression portion has durometer value substantially smaller than the durometer value of the engaging portion.

Description:
CROSS-REFERENCE To RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority under 35 U.S.C. §119(a) to Finnish Patent Application 20126244 filed on Nov. 27, 2012. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to logistics equipment. In particular, the invention relates to roll container accessories. 
       BACKGROUND 
       [0003]    Roll containers are wheeled pallets which are used to transport and store parceled goods. Roll containers are particularly popular in delivering parcels from a storage or logistics hub to a retailer. Conventional roll containers are constructed of metal frame sections which are attached to each other by means of fixed attachments and hinges. During transport these metal frame sections make contact, which results in a considerably amount of noise which is a strain for the occupational safety logistics employees. 
         [0004]    In addition to occupational safety regulations, certain municipalities may impose noise legislation regulating the level noise acceptable for deliveries in residential areas. One example of legislation regulating peak noise during loading and unloading of goods in transportation is the so called TNO report MON-RPT-2010-00466 (2010 update). The report divides the day into three periods and defines acceptable noise levels for each period. According to the TNO report there are no restrictions for the period of day beginning at 7 a.m. and ending at 7 p.m. However, for the period from 7 p.m. to 11 p.m. the report sets a maximum noise level of 65 dB(A). For the period from 11 p.m. to 7 a.m. the level further restricted to 60 dB(A). Accordingly, the maximum noise levels for late deliveries set a rather high standard for logistics equipment used for such deliveries. 
         [0005]    The noise generated by roll containers is a known issue for which there have been several attempts to produce low-noise roll containers. JP 2002347765 A, for example, discloses a silencing liner to be applied to inner surfaces of the profiles of frame sections of roll containers for dampening vibrations thereof. However, the silencing solution proposed by JP 2002347765 A may not be retro-fitted to existing roll containers, whereby it is not feasible for solving the problem of silencing conventional roll containers. Furthermore, while JP 2002347765 A does have silencing properties, it does not sufficiently eliminate sound resulting from two metal pieces making contact. 
         [0006]    JP 2003321025 A discloses a plastic sleeve which may be retrofitted on a roll container profile. While the sleeve of JP 2003321025 A eliminates some rattle, it is not ideal because fails to dampen the vibration of the profile compared to JP 2002347765 A. 
         [0007]    It is therefore an aim of the present invention to provide a silencer profile for a roll container which can be retro-fitted and which eliminates noise resulting from metal frame sections of the roll container making contact. 
       SUMMARY 
       [0008]    The aim of the present invention is achieved with aid of a novel silencer for a roll container. The silencer includes an engaging portion having an interior surface which is configured to engage to a profile of the roll container in an at least partly enclosing manner. The engaging portion also has an exterior surface which opposes the interior surface. The silencer also includes a compression portion which is formed on the exterior surface of the engaging portion for receiving external impacts. The compression portion features a relieved profile for extending the compression length the compression portion. The compression portion has durometer value which is substantially smaller than the durometer value of the engaging portion. 
         [0009]    Considerable benefits are gained with aid of the present invention. Similar to known retro-fit silencers, the novel silencer has an engaging portion which may be manufactured from a durable material which is suitable for firmly enclosing the profile. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In the following, exemplary embodiments of the invention are described in greater detail with reference to the accompanying drawings in which: 
           [0011]      FIG. 1  presents a side elevation view of a buffer according one embodiment in a closed configuration, 
           [0012]      FIG. 2  presents an isometric view of the buffer profile of  FIG. 1  in an opened configuration, 
           [0013]      FIG. 3  presents a side elevation view of a buffer according to a second embodiment, 
           [0014]      FIG. 4  presents a side elevation view of a buffer profile according to a third embodiment in an opened configuration, 
           [0015]      FIG. 5  presents a side elevation view of buffer profile of  FIG. 4  in a closed configuration, 
           [0016]      FIG. 6   a  presents a rear isometric view of the buffer profile of  FIG. 4 , 
           [0017]      FIG. 6   b  presents a rear isometric view of the buffer profile of  FIG. 5 , 
           [0018]      FIG. 7   a  presents a front isometric view of the buffer profile of  FIG. 4 , 
           [0019]      FIG. 7   b  presents a front isometric view of the buffer profile of  FIG. 5 , 
           [0020]      FIG. 8  presents a side elevation view of the buffer profile of  FIG. 4  arranged to the meshing of a roll container, and 
           [0021]      FIG. 9  presents a side elevation view of the buffer profile of  FIG. 5  arranged to the meshing of a roll container. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The first embodiment of the invention is presented  FIGS. 1 and 2  which show one exemplary silencer  100  in an open and closed configuration, respectively. The silencer  100  shown in the figures includes an engaging portion  110 , the interior surface of which is configured to enclose a rounded quadrilateral roll container profile. The engaging portion  110  is made of durable material having a durometer value in the range of 90 to 100 shore A, such as 96 to 100 shore A. Suitable materials for the engaging portion  110  include PA, PP, HDPE or hard PVC. The material of the engaging portion  110  is in other word selected primarily to withstand strain. The engaging portion  110  is designed to feature one part having two halves connected to each other from a hinging seam and from an opposing snap fit.  FIG. 2  presents one example of a hinged single-body construction. Alternatively the engaging portion  100  could be constructed from two separate halves which may be joined together by two opposing snap fits (not shown). 
         [0023]    The exterior surface of the engaging portion, i.e. the outer envelope surface, includes a compression portion  120  which is intended for receiving external impacts originating from, for example, various parts of a roll container making contact or from two roll containers coming into contact. The compression portion  120  features a relieved profile  121  for extending the compression length the compression portion  120 . A relief is in context referred to as a reduction of material compared to a solid design. In the example shown in  FIGS. 1 and 2 , the profile is relieved by means of a plurality of external recesses. In other words the outer envelope surface of the compression portion  120  features grooves which extend around the axis of the silencer  100  and therefore around the axis of the receptive profile. The recesses make the compression portion  120  more prone to deform when subjected to an impact as the compression length is extended compared to a solid structure. 
         [0024]    The compression portion  120  is made of material which has a durometer value which is substantially smaller than the durometer value of the engaging portion  110 . Referring to the exemplary durometer value 90 to 100 shore A for the engaging portion  110 , the corresponding durometer value for the compression portion  120  would be in the range of 50 to 70 shore A. Suitable materials for the compression portion  120  include TPE and soft PVC, for example. In other words, the durometer value of the compression portion  120  is, according to one embodiment, at most 80 per cent of the durometer value of the engaging portion  110 . The materials of the engaging portion  110  and compression portion  120  need necessarily not be of different materials; they may be selected of the same material composition such modified to yield different durometer values. 
         [0025]    A particularly advantageous construction for such a silencer may be produced by means of a multi-compound mold piece, wherein the engaging portion  110  and the compression portion  120  are of different compounds having different durometer values. This approach makes is possible to produce the silencer in a single manufacturing stage by simultaneously ensuring that the two portions  110 ,  120  are tightly joined. 
         [0026]    On a general level, the silencer  100  comprises a main extending dimension, wherein the portions  110 ,  120  of the silencer  100  are shapes defined in the normal plane of the main extending dimension of the silencer  100 . Accordingly, the first embodiment described above may therefore by modified while maintaining similar technical effects. 
         [0027]    The second embodiment of the invention is presented  FIG. 3  which shows one exemplary silencer  100  which is intended to be attached to a rectangular profile by means of a snap fit and which features an inner relief. The second embodiment features a compression portion  120  which extends in a looping fashion from and to the exterior surface of the engaging portion  110  so as to form a hollow flexing cavity  121 . More precisely, the compression portion  120  is integrated to the engaging portion  110  such that the compression portion  120  protrudes from one point of the engaging portion  110  and merges into another point of the engaging portion  110  so as to form the flexing cavity  121  within the loop defined by the compression portion  120  and the engaging portion  110 . From  FIG. 3  is may be seen how the two portions  110 ,  120 , which are joined through multi-compound molding, merge together. The compounds are distinguished in the Figure by opposing hashing angles. The flexing cavity  121  is therefore defined by the external surface of the engaging portion  110  and the compression portion  120 . As in the first embodiment, the compression portion  120  is preferably an integral part of the silencer profile ( 100 ) by means of a multi-compound mold piece, for example. 
         [0028]    The hollow flexing cavity  121  is configured to buckle, i.e. collapse, elastically when subjected to an impact. Because the compression portion  120  is relieved by means of such an inner cavity and because the compression portion  120  is made of a material with a relatively low durometer value, the construction is able to effectively dampen sound resulting from roll container elements making contact. 
         [0029]    Also the engaging portion  110  differs from that of the first embodiment. The engaging portion  110  according to the second embodiment is configured to enclose a profile of the roll container only partly. The interior surface for engaging with the profile of a roll container is formed by the surfaces defining the imaginary volume for receiving the profile, i.e. the surfaces resembling an inverted letter C in  FIG. 3 .  FIG. 3  also shows that the engaging portion  110  features two opposing claws which are configured to snap on to a thin rectangular profile. It is to be understood that the engaging portion  110  may be further modified to be suitable for other profiles without departing from the claimed inventive concept. 
         [0030]    The third embodiment of the invention is presented in  FIGS. 4 to 9  which show a different approach to designing the engaging portion  110 . According to the third embodiment, the engaging portion  110  has been provided with a recess  111  for at least partially embedding a profile  202 , particularly a thin circular profile such as a horizontal meshing wire of the roll container ( FIGS. 8 and 9 ). The compression portion  120  is similar to that described in connection with the second embodiment ( FIG. 3 ). According to the third embodiment, the compression portion  120  and the recess  111  extend in the same dimension and to the same direction from the engaging portion  110  such that the compression portion  120  extends farther than the recess  111  ( FIGS. 4 and 5 ). 
         [0031]    The engaging portion  110  includes a counterpart portion  112  which is pivotably attached to the engaging portion  110 , whereby the engaging portion  110  and the counterpart portion  112  are provided with mutually cooperating form fitting conformations  113 ,  114  for locking the engaging portions  110  around the profile of the roll container. In this respect, it is the internal surfaces of the recess  111  and the corresponding surface of the counterpart portion  112  that form the internal surface of the silencer for engaging with the profile of a roll container. Also the counterpart portion  112  is an integral part of the silencer  100 , wherein the counterpart portion  112  has two opposing ends, the first of which is pivotably merged into the engaging portion  110  and the opposing second is provided with the form fitting conformation  114 . Thus, the counterpart portion  112  is configured to close the recess  111  of the engaging portion  110  when the form fitting conformations  113 ,  114  are interlocked, wherein the recess  111  and the counterpart portion  112  form a closed cavity for receiving the profile  202  of the roll container ( FIGS. 5 and 8 ). 
         [0032]    Compared to the second embodiment shown in  FIG. 4 , the two portions  110 ,  120  in the third embodiment are more prominently distinguished as the first portion  110  is shaped to provide attachment recesses for the second portion  120 . The inner surfaces of the attachment recesses of the first portion  110  provide an ample gripping surface for the external surfaces of the second portion  120 , which should preferably be taken into consideration when designing the multi-compound piece and mold. 
         [0033]      FIGS. 6 and 7  illustrate that the silencer according to the third embodiment—as well as to the second embodiment alike—may be constructed as a profile. According to the third embodiment, the silencer  100  comprises a plurality of counterpart portions  112  arranged to single engaging portion  110  successively along the main extension dimension. The counterpart portions  120  are separated by a gap which is configured to receive a vertical mesh wire of the roll container. The gaps are orthogonal to the main extending dimension of the silencer profile  100 . As in the first and second embodiments, the profile-like silencer  100  features a main extending dimension such that the portions of the silencer  100  are shapes defined in the normal plane of the main extending dimension of the silencer profile  100 . Furthermore the profile  202  of the roll container is parallel to the main extending dimension of the silencer profile  100 . 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 LIST OF REFERENCE NUMBERS. 
               
             
          
           
               
                   
                 umber 
                 Part 
               
               
                   
                   
               
               
                   
                 00 
                 silencer 
               
               
                   
                 10 
                 engaging portion 
               
               
                   
                 11 
                 recess 
               
               
                   
                 12 
                 counterpart portion 
               
               
                   
                 13 
                 form fitting conformation 
               
               
                   
                 14 
                 form fitting conformation 
               
               
                   
                 20 
                 compression portion 
               
               
                   
                 21 
                 flexing cavity 
               
               
                   
                 01 
                 profile: vertical meshing wire 
               
               
                   
                 02 
                 profile: horizontal meshing wire 
               
               
                   
                   
               
             
          
         
       
     
         [0034]    The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.