Abstract:
A device for sampling fluids that has an outer conduit having a first end connected to a non-pressurized fluid reservoir and a second end adjacent to the testing location that is remote from the fluid reservoir. An inner fluid conduit is positioned within the outer conduit, the inner fluid conduit having a first end extending into the fluid reservoir and the second end adjacent to the testing location, the second end having a connector. A pressure source selectively connects to the connector and selectively applies a vacuum to the second end of the inner fluid conduit to draw fluid from the through the inner fluid conduit and applying pressure to purge the inner fluid conduit of fluid.

Description:
FIELD 
     This relates to a fluid sampling device for obtaining a sample from a remote location. 
     BACKGROUND 
     It is often necessary to draw fluids from a fluid reservoir for testing purposes. Hand pumps and electric pumps are often used to draw fluid into a sample container. 
     SUMMARY 
     There is provided a device for sampling fluids, comprising a fluid conduit having an inlet in communication with fluids to be sampled, and an outlet connected to a sample container. A pressure source selectively applies a vacuum to draw fluid through the fluid conduit into the sample container and applies pressure to purge the fluid conduit of fluid. 
     According to another aspect, there is provided a device for sampling fluids, comprising an outer conduit having a first end connected to a non-pressurized fluid reservoir and a second end adjacent to the testing location that is remote from the fluid reservoir, and an inner fluid conduit positioned within the outer conduit, the inner fluid conduit having a first end extending into the fluid reservoir and the second end adjacent to the testing location, the second end having a connector. A pressure source selectively connects to the connector and selectively applies a vacuum to the second end of the inner fluid conduit to draw fluid through the inner fluid conduit and applying pressure to purge the inner fluid conduit of fluid. 
     According to another aspect, the fluid reservoir may be a hydraulic reservoir for a vehicle, and the testing location may be a vehicle access opening. 
     According to another aspect, the fluid reservoir comprises a removable cap, the first end of the outer conduit being connected to the removable cap. 
     According to another aspect, the inner fluid conduit may be removable from the outer conduit, and the first end of the inner fluid conduit may comprise a fluid level indicator. The fluid level indicator may comprise a concave surface. 
     According to another aspect, the pressure source may draw fluid into a sample container, and the pressure source may connect to the connector of the inner fluid conduit via the sample container. 
     According to another aspect, there is provided, in combination, inner and outer conduits, a pressure source, a sample container, and a connector. The inner fluid conduit are positioned within the outer conduit, the outer conduit being connected between a fluid reservoir and an testing location spaced from the fluid reservoir, the inner fluid conduit having a first end that extends into the fluid reservoir and a second end adjacent to the access point. The pressure source selectively applies a vacuum to the second end of the inner fluid conduit to draw fluid through the inner fluid conduit into the sample container and applying pressure to purge the inner fluid conduit of fluid. The sample container collects fluid drawn through the inner conduit. A connector selectively connects the pressure source, the second end of the inner conduit, and the sample container. 
     According to another aspect, the fluid reservoir may be a hydraulic reservoir for a vehicle, and the testing location may be a vehicle access opening. 
     According to another aspect, the fluid reservoir comprises a removable cap, the first end of the outer conduit being connected to the removable cap. 
     According to another aspect, the inner fluid conduit may be removable from the outer conduit, and the first end of the inner fluid conduit may comprise a fluid level indicator. The fluid level indicator may comprise a concave surface. 
     According to another aspect, the pressure source may draw fluid into a sample container, and the pressure source may connect to the connector of the inner fluid conduit via the sample container. 
     According to another aspect, the connector may comprise a lid of the sample container, the lid comprising a first connector for connecting to the inner fluid conduit and a second connector for connecting to the pressure source. The pressure source may connect to the connector of the inner fluid conduit via the sample container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein: 
         FIG. 1  is a schematic view of a device for sampling fluid. 
         FIG. 2  is a perspective view of a mining truck. 
         FIG. 3  is a detailed side elevation view of a fluid reservoir. 
         FIG. 4  is a side elevation view of an attachment for attaching the fluid conduit adjacent to an access point. 
         FIG. 5  is a side elevation view of the attachment of  FIG. 4  with an inner conduit being withdrawn from an outer conduit. 
         FIG. 6  is a side elevation view of a fluid conduit attached to a cap for a fluid reservoir. 
         FIG. 7  is a side elevation view of the fluid reservoir of  FIG. 6  with the fluid conduit being detached from the cap. 
         FIG. 8  is a side elevation view of a sample container. 
         FIG. 9  is a side elevation view of a pressure source. 
     
    
    
     DETAILED DESCRIPTION 
     A device for sampling fluid, generally identified by reference numeral  10 , will now be described with reference to  FIG. 1 through 9 . 
     Structure and Relationship of Parts: 
     Referring to  FIG. 1 , device for sampling fluids  10  includes a fluid conduit  12  having an inlet  14  in communication with fluids to be sampled, and an outlet  16  connected to a sample container  18 . Referring to  FIG. 3 , fluid conduit  12  is preferably an inner fluid conduit (shown in dotted lines), and is installed within an outer conduit  13 . Outer conduit  13  is used to protect inner fluid conduit  12 , and in a preferred embodiment, fluid conduit is removable from outer conduit  13 . As outer conduit  13  preferably acts primarily as a guide and protective sheath, it may not be made from impermeable material. Preferably, it will be made from a material that resists damage. Fluid conduit  12  is preferably a flexible hose that can withstand the vacuum pressures necessary to draw fluid into sample container  18 , and the pressures necessary to purge the fluid after the sample has been taken. Fluid conduit  12  must be selected to provide a balance between friction between the liquid being sampled and fluid conduit  12 , and the viscosity of the fluid being sampled. In the example discussed below where hydraulic fluid from an reservoir in mining truck  19  as shown in  FIG. 2 , with an electric drive  21  as shown in  FIG. 1 , adequate results have been achieved using 5/16″ hose size. 
     Referring to  FIG. 1 , the pressure and vacuum are applied to fluid conduit  12  by a pressure source  20  that has a pressure mode and a vacuum mode. Referring to  FIG. 9 , pressure source  20  preferably has a pressure port  22  and a vacuum port  24  that are that are connected to an electric compressor  25 , where the mode of pressure source  20  is changed by making the appropriate connection. Referring again to  FIG. 1 , pressure source  20  is used to apply a vacuum to draw fluid through fluid conduit  12  into sample container  18  and then to apply pressure to purge the fluid conduit of fluid. As depicted, sample container  18  is connected to pressure source  20  by another hose  26 . Referring to  FIG. 8 , the connection between fluid conduit  12 , pressure source  20  and an example of a sample container  18  are preferably made though the lid  28  of sample container  18 . As shown in  FIG. 1 , fluid conduit  12  is connected to lid  28  via hose  40 , and pressure source  20  is connected to lid  28  via hose  26 . Pressure source  20  can then apply positive or negative pressure to the sample container  18  to draw fluids through or purge fluid from fluid conduit  12  until it is disconnected from lid  28 . It will be understood that pressure source  20  may be connected to fluid conduit  12  in different ways in order to collect a fluid sample, depending on the design of pressure source  20  and sample container  18 . However, the design described permits the device to be used with commonly available equipment and products. 
     In one embodiment, referring to  FIG. 9  pressure source  20  is a 12 V vacuum/compressor  25  that can be powered by a standard power outlet in a vehicle or by a battery pack. Pressure source  20  is preferably portable and is contained within a carrying case  29 . Pressure source  20  may also have a transformer that allows it to be powered from a standard 110 V socket, or other common power supply. There may be a filter included to protect the components (not shown). In other embodiments, an air pressure regulator and a vacuum generator may be used to accommodate a pressurized air source. 
     In a preferred embodiment, referring to  FIG. 1 , device  10  is used to draw fluids from an unpressurized fluid reservoir  30  that is remote from an access point  32 . For example, in electric drive mining trucks  19 , oil is often contained in reservoir  30  that is spaced from an access point  32 , such as a manway. This requires personnel to enter a confined compartment to reach the fluid reservoir  30  when it is necessary to obtain a fluid sample. Referring to  FIG. 1 , fluid conduit  12  is installed with inlet  14  in constant communication with fluid reservoir  30 , while outlet  16  is mounted adjacent to access point  32  using a bracket  33 , as shown in  FIG. 4 . Bracket  33  is shaped such that outlet  16  is held recessed from access point  32  to prevent any interference with opening and closing access point  32 . Outlet  16  is preferably designed with a quick-connect nipple  34 , so that sample container  18  may be easily connected and disconnected. Referring to  FIG. 5 , in order to remove fluid conduit  12  from outer conduit  13 , fluid conduit  12  preferably has a connector  36  that connects to bracket  33 . 
     Inlet  14  may be mounted to fluid reservoir  30  by various means. In the example shown in  FIG. 3 , inlet  14  is mounted to a cap  38  of the fluid reservoir  30 . By having fluid conduit  12  pass through cap  38 , cap  38  does not need to be removed, which reduces the risk of contaminating fluid reservoir  30  when compared with the traditional method of removing cap  38  to insert a fluid sampler. As depicted in  FIGS. 6 and 7 , cap  38  is also used to hold a magnetic filter element  39 . Many cap designs that are common on non-pressurized tanks are suitable and may be used. As shown, outer conduit  13  is attached by a swivel connection  41 . Other types of connections may be used. This allows cap  38  to be easily removed or installed for service. Inner conduit  12  is preferably not secured directly to cap  38  to allow it to be removed by releasing connection  36 . Alternatively, if inner conduit  12  is not removable, a quill tube (not shown) may be attached to cap  38  that extends downward into oil reservoir  30  to act as the inlet  14  end of hose  12 . As depicted in  FIGS. 6 and 7 , outer conduit  13  preferably attaches to cap  38 , and inner fluid conduit  12  may pass through cap  38  to access fluid directly. Preferably, the connections between inner conduit  12 , outer conduit  13  and cap  38  are swivel connections to prevent twisting of the conduits during installation. 
     As mentioned above, fluid conduit  12  is preferably removable, such that it can also act as a dip stick. In other embodiments, it may be desirable to provide a fluid level indicator, or “dip stick” that can be inserted through the outer conduit  13  or inner conduit  12  to check the fluid level in the fluid reservoir  30 . Alternatively, there may be a hole in the portion of fluid conduit  12  that is intended to be submerged in oil to act as a vacuum break. In this example, if the fluid level is below the minimum threshold, fluid will not be extracted through conduit  12 . 
     Referring to  FIG. 6 , inlet  14  of fluid conduit  12  has a minimum fluid level indicator portion  44 , which consists of a cutaway portion of the tube. This forms a vacuum break that prevents a sample from being drawn if the fluid level is below a minimum threshold. In addition, the bottom of fluid conduit  12  may be used as a fluid level indicator, i.e. a dipstick. This may be done by texturing the outer surface at the bottom  45  of fluid conduit  12 , such as by sanding, so that any oil will adhere to the surface and allow an operator to check the level. This embodiment allows the same tubing  12  to be used to remove a fluid sample by technicians, and as a fluid level check by operators. Outer conduit  12  may also be connected to the reservoir cap by a swivel connection to prevent twisting during installation. Referring to  FIGS. 4 and 5 , fluid conduit  12  preferably has a quick connect nipple coupler  34  to connect to pressure source  20  in order to purge fluid back into reservoir  30 . Outer conduit conduit  13  may terminate at mounting bracket  33  as shown, or it may be mounted in other ways that will be apparent to those skilled in the art. 
     Operation: 
     Referring to  FIG. 1 , fluid conduit  12  is installed with inlet  14  in communication with fluid reservoir  30  and outlet  16  mounted adjacent to an access point  32 , such as a manway in the housing that houses fluid reservoir  30 . When it is necessary to draw a sample, manway  32  is opened, and sample container  18  is attached to fluid conduit  12 . As shown, sample container  18  has an additional hose  40  to connect to fluid conduit  12 . Vacuum port  24  of pressure source  20  is then connected via hose  26  to sample container  18  to apply vacuum pressure to sample container  18  to draw a sample from fluid reservoir  30  into sample container  18  through inner conduit  12  via hose  40 . Generally, two sample containers  18  are filled, with the first being drawn to flush the line and is discarded. Once the necessary samples are obtained, fluid conduit  12  is connected to pressure port  22 , either directly or through sample container  18 , to blow down any remaining fluid in fluid conduit  12 . As there will generally be two reservoirs  30  for each axle tube, the process is repeated for the other reservoir  30 . There will preferably be a fluid conduit  12  installed for each reservoir  30 , such that pressure source  20  is reconnected by a new sample container  18  to another fluid conduit  12 . 
     In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. 
     The following claims are to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, and what can be obviously substituted. Those skilled in the art will appreciate that various adaptations and modifications of the described embodiments can be configured without departing from the scope of the claims. The illustrated embodiments have been set forth only as examples and should not be taken as limiting the invention. It is to be understood that, within the scope of the following claims, the invention may be practiced other than as specifically illustrated and described.