Patent Publication Number: US-2018054031-A1

Title: Relating to, heating

Description:
PRIORITY CLAIM 
     This application claims the benefit of New Zealand Patent Cooperation Treaty application number PCT/NZ2016/050073, filed May 9, 2016, which claims benefit to New Zealand application number NZ 707891, filed May 8, 2015, the contents of which are incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to electrical connections for slip heater pads. 
     In particular, though not solely, the present invention is directed to dual voltage connectors which are passive and allow for connection to one or another voltage to power a universal slip heater pad for example for heating of an Intermediate Bulk Container (IBC). 
     BACKGROUND OF THE INVENTION 
     A problem arises when product moves from one country to another that requires an electrical connection. This problem is further compounded when it moves from one country to another and those countries have differing electrical levels, for example 230 VAC for Australia or New Zealand, and then 115 VAC for the United States. 
     There have been various solutions up until now. 
     One solution to connecting the same item into both voltages has required an active power supply to drop or raise the voltage to the operating voltage of the connected equipment. This has the problem of the added cost and potential fragility of the power supply. This problem is exacerbated when the attached equipment is considered a throwaway product, and therefore there is no re-use of the equipment or power supply. This leads to cost and waste. 
     The solution of having these power sources at each site is undesirable from a point of view of cost and maintenance, and the location may not have the ability or capacity to support a multitude of power supplies, sources and connections. 
     Another solution is to have the equipment requiring connection to have dual circuits, one rated for one voltage and another rate for another, and so on. This duplication can be wasteful in cost and materials because it may only be one voltage connection ultimately that is needed, for example at destination. Therefore the duplicated circuit for the other voltage is not used. 
     Another solution can be the use of an interchangeable circuit board to allow connection 240 VAC and 110 VAC to the connected equipment. However the cost of such circuit board systems can be relatively high and reliability may become an issue. Also this system requires the time and effort of the user to switch the circuit board over and is reliant on the user having checked the correct circuit board is in place or changing the board over for the correct voltage. This is a draw back and may allow connection of the incorrect voltage. 
     In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art. 
     It is therefore an object of the present invention to provide an improved multi-voltage electrical connection, or to overcome the above shortcomings or address the above desiderata, or to at least provide the public with a useful choice. 
     SUMMARY OF THE INVENTION 
     In a first aspect the present invention may be said to broadly consist in a multi-voltage electrical apparatus comprising or including an electrical load that can connect via an electrical connection separately to both of either a first electrical source at a first voltage, and a second electrical source at a second voltage, wherein said electrical load is connected in series via said electrical connection to said first electrical source, or in parallel via said electrical connection to said second electrical source, said electrical load when connected in series or parallel having substantially the same power output. 
     Preferably said electrical load is a resistive heater. 
     Preferably said power output of said electrical load is substantially thermal. 
     Preferably said load is a resistive heater for any one or more of, 
     an intermediate bulk container, 
     bulk containers, 
     drums, 
     barrels 
     storage containers, 
     tanks, and 
     hoppers. 
     Preferably said electrical connection has a termination for connection with said electrical load. 
     Preferably said electrical connection is supplied at least with said termination in a first configuration for series connection of said electrical load to said first electrical source. 
     Preferably said electrical connection is supplied with said termination in a second configuration for parallel connection of said electrical load to said second electrical source. 
     Preferably said electrical load has a connection point that can connect to said termination in both said first configuration and said second configuration. 
     Preferably said series or parallel connection of said electrical load is achieved through series or parallel connection of said electrical load to said first electrical source and said second electrical source respectively via connection of said termination and said connection point. 
     Preferably said termination consists of a socket. 
     Preferably said connection point is a plug. 
     Preferably said termination is at an end of a flexible electrical lead, distal from said power source. 
     Preferably said connection point is at a periphery of said electrical load. 
     Preferably said electrical connection has electrical contacts arranged therein to connect said load in parallel or series dependent on whether said first termination or said second termination is connected thereto. 
     Preferably said first voltage is higher than said second voltage. 
     Preferably said first voltage is 240 volts alternating current. 
     Preferably said second voltage is 110 volts alternating current. 
     Preferably said connection point is mounted on said electrical load, said container or part thereof, or remote from the electrical load at the end of an electrical lead. 
     In another aspect the present invention may be said to broadly consist in a heating element adapted to heat an intermediate bulk container, comprising or including an electrical load that can connect via an electrical connection separately to both of either, a first electrical source at a first voltage, and a second electrical source at a second voltage, wherein said first electrical source via said electrical connection is applied to said load in series, and said second electrical source via said electrical connection is applied to said to load in parallel, said electrical load when connected in series or parallel said having substantially the same power output. 
     In another aspect the present invention may be said to broadly consist in a multi-voltage electrical apparatus as described herein with reference to any one or more of the accompanying drawings. 
     In another aspect the present invention may be said to broadly consist in a heating element as described herein with reference to any one or more of the accompanying drawings. 
     As used herein “(s)” following a noun means the plural and/or singular forms of the noun. 
     The term “comprising” as used in this specification means “consisting at least in part of”. When interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present, but other features can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in the same manner. 
     It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7). 
     The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference. 
     This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements and features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. 
     Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1  shows at (A) and (B) the circuit diagrams of the electrical load connected to an alternating current electrical (first) source in series, and (C) the same electrical load connected to an alternative current electrical (second) source in parallel, and (D) the circuit diagram for the parallel connection, 
         FIG. 2  shows in plan view the electrical load as a slip pad heater, for example as used to heat an intermediate bulk container, 
         FIG. 3  shows the slip pad heater located underneath an intermediate bulk container and above a pallet, 
         FIG. 4  shows a socket as an example of a termination for the electrical sources, in (A) end elevation, (B) side elevation, and (C) top elevation, 
         FIG. 5  shows a plug for said electrical load complimentary to the socket of  FIG. 4  in (A) end elevation, (B) side elevation, and (C) top elevation, 
         FIG. 6  shows a diagram for connection between the termination from the electrical source and the connection on the electrical load for series connection, and 
         FIG. 7  shows a diagram for connection between the termination from the electrical source and the connection on the electrical load for parallel connection. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Preferred embodiments will now be described with reference to  FIGS. 1 through 7 . 
     A multi-voltage electrical apparatus  1  is shown in  FIG. 1  in wired in series (A and B) and parallel (C and D). The electrical load in one preferred form is a planar winding of resistance wire or heater cable with a given resistance per length (Ohms/m). This planar array, as resistance wire, is shown in  FIG. 2  where the planar array is a slip pad heater  15 . A slip pad heater  15  as earlier described is used to heat the content of an intermediate bulk container  9 , as shown in  FIG. 3 . As shown in  FIG. 3  the slip pad heater  15  is located or incorporated in the components between the bulk container  9  that contains the product to be heated and the pallet  17  the container  9  rests on. As the container content will often weigh in excess of a 1000 kg and the container  9  is fragile the slip pad heater  15  is located underneath the container  9  and above the pallet  17  (or equivalent) in most cases prior to filling the container  9  with its content. Location under the bulk of the product to be heated also enables sufficient heat transfer to the contents of the container due to the increased contact pressure between the container  9  and the heater  15  due to the weight of the product in the container  9 . 
     The slip pad heater  15  shown in  FIG. 2  is of known construction and the resistance wire is often laminated between two sheets of film, for example aluminium foil or similar as heat conducting material directly against the container, and heat reflecting material on the outside of the slip pad heater to reflect heat back towards the container  9 . In other embodiments the underside may be of paper based material as this is cost effective. The heater  15  is made from a length of resistance wire or heater cable, for example as laid out as shown. The ends of the length terminate in electrical contacts  16 A and  16 C, and also a mid-point (resistance wise) connection  16 B. An earth connection  16 D is also shown to allow earthing of the heater  15 . 
     The parallel and series electrical connection of the electrical load is shown schematically in  FIG. 1A ,B for series and  FIG. 1  C, D for parallel. In the preferred form there are three electrical contacts  16 A,  16 B and  16 C, and optionally a fourth electrical contact  16 D as an earth on the electrical load, and electrical source live  21 , electrical source neutral  22 , and electrical source earth  23 . 
     In the series form, shown in  FIGS. 1A ,B and  FIG. 6 , the first electrical source  4  is connected in series across electrical load contacts  16 A and  16 C as shown to form the series circuit with known electrical resistance Rs. In the preferred embodiment electrical source live  21  is connected to electrical contact  16 A, electrical load neutral  22  connected to electrical load contact  16 C (or vice versa) and electrical source earth  23  connected to electrical load earth  16 D. 
     In the preferred form the first electrical source  4  is 240 Volts alternating (VAC) current, also referred to as 230 VAC, and sometimes as 220 VAC. Other electrical connections may be present for other purposes but are not shown here and are not part of the present invention. 
     In the parallel form, shown in  FIGS. 1C ,D and  FIG. 7 , the second electrical source  6  is connected in parallel across electrical load contacts  16 A/ 16 C and  16 B as shown to form the parallel circuit with known electrical resistance Rp. In the preferred embodiment electrical source live  21  is connected to electrical contact  16 A and  16 C, electrical load neutral  22  connected to electrical load contact  16 B (or vice versa) and electrical source earth  23  connected to electrical load earth  16 D. 
     In the preferred form the second electrical source  6  is 115 Volts alternating (VAC) current, also referred to as 110 VAC, and sometimes as 120 VAC. Other electrical connections may be present for other purposes but are not shown here and are not part of the present invention. 
     In use the slip pad heater  15  is located external to the container, and in the preferred embodiment, it is under the intermediate bulk container  9 , as shown in  FIG. 3 . However, in other forms the heater  15  can be located on top, or about the side, or sides of the contents, or a combination thereof, that requires heating by the resistive heater  8 . 
     When the content of the container  9  needs to be heated the heater  15  is connected to the available electrical source  4  or  6 —the voltage of which will depend on typically the geographic location the container  9  is in. For example if the container  9  is in the United States the electrical source would typically be 110 VAC (or 115 VAC), and if in New Zealand the voltage would be 230 VAC (or 240 VAC). The present invention contemplates the electrical source is, in the preferred embodiment, single phase. 
     The connection to the electrical source  4  or  6  in the preferred form is by an electrical cord  18 . At the electrical source  4 , 6  end  19  of the cord  18  there is the typical connection required for that particular source, e.g. three pin plug for New Zealand. At the heater connecting end  20  there is the connection  3  with the resistive heater  8  of the slip pad heater  15 . In the preferred embodiment this electrical connection  3  is achieved via a termination that is a socket  12  from the electrical source and a plug  13  as a connection point from the resistive heater  8 . However, other forms may be acceptable also. The electrical connection  3  may extend from the slip pad heater  15  with a cord as shown, or may be located on the slip pad heater  15  itself, or maybe mounted on the container  9 . 
     The socket  12  (in the preferred embodiment) of the electrical connection  3  has two configurations, a first  12 A (for first termination) and second  12 B (for second termination), as shown in  FIGS. 6 and 7 . The first  12 A connects via the plug  13  (as the connection from the electrical load) the electrical load  2  (for example as shown the resistive heater  8 ) in series to the first electrical source  4 , and the second  12 B connects via the plug  13  the electrical load (for example as shown the resistive heater  8 ) in parallel to the second electrical source  6 . All the contacts  16 A,  16 B, and  16 C are located in the plug  13 , and it is the specific sockets  12 A and  12 B and the arrangement of their connections inside that connects them in series or parallel with the electrical load of the slip pad as necessary. 
     As can be seen in  FIG. 4A  the plug  12  has so that it can only fit into the plug  13  in one way, thus ensuring correct alignment of the contacts each time. In the preferred form shown there are complimentary keys  24  and keyways  25  in the socket  12  and plug  13  to ensure they connect in the right orientation each time. Optionally there may also be locking portions to hold the two together in addition to any friction between the two, for example, but not limited to clips, or a bayonet style one or two part twist connection (not shown). 
     Therefore the electrical cord  18  and specific socket  12  connected is specific to a voltage. For example the first socket  12 A and its cord  18  for series connection is supplied for example to 230 Vac countries and the second socket  12 B and its cord  18  for parallel connection is supplied to 115 Vac countries. 
     While a plug  13  and socket  12  connection is described here, it could be a socket and plug connection, or any other form of equivalent electrical connection. 
     When the first electrical source  4  is connected as described above, and is preferably at the higher voltage, the electrical connection  3  connects the resistive heater  8  in series as shown in  FIGS. 1A , and B. This is achieved by the arrangement of electrical contacts  21 ,  22  and  23  within the socket  12 A, and their connection to those in the plug  13 , as described above. One possible configuration is shown in  FIG. 6  where the first socket  12  A is shown and has contacts to the first electrical source of electrical source live  21 , electrical source neutral  22  and electrical source earth  23 —the fourth contact shown has no electrical function assigned. Likewise in the plug  13 , there is the contact  16 A to one arm of the electrical load  2 , which connects in this configuration to electrical source live  21  in the socket  12 A. Likewise there is electrical contact  16 C (to the other arm) to electrical source neutral  22 , and electrical contact  16 D (earth) to electrical source earth  23 . 
     In the alternative when the second electrical source  6  is connected as described above, and is preferably the lower voltage, the electrical connection  3  connects the resistive heater  8  in parallel as shown in  FIGS. 1C  and D. This is achieved by the arrangement of electrical contacts  21 ,  22 , and  23  within the socket  12 B, and their connection to those in the plug  13 , as described above. One possible configuration is shown in  FIG. 7  where the second socket  12 B is shown and has two live contacts to the first electrical source of electrical source live  21 , electrical source neutral  22  and electrical source earth  23 . Likewise in the plug  13 , there is the contact  16 A and  16 C to one arm of the electrical load  2 , which connects in this configuration to electrical source live  21  in the socket  12 A. Likewise there is electrical contact  16 B (to the other arm) to electrical source neutral  22 , and electrical contact  16 D (earth) to electrical source earth  23 . 
     The advantage of the present invention is that irrespective of the location of the container  9  and the voltage in that country, the slip pad heater with a standardised plug can be connected by use of the correct plug to the electrical source present. This has advantages in that the slip pad heater, and its electrical connection can be standardised, yet still work with dual voltages. 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.