Patent Publication Number: US-2012042987-A1

Title: Unit for repairing and inflating inflatable articles

Description:
TECHNICAL FIELD 
     The present invention relates to a unit for repairing and inflating inflatable articles, such as a punctured vehicle tyre. 
     BACKGROUND ART 
     A punctured tyre can be replaced with a spare wheel stowed in a compartment on the vehicle, e.g. under the floor of the boot, in the case of a car. 
     The spare wheel, however, is bulky, and takes up space in the boot, which could be put to better use. 
     The spare wheel is also heavy, which makes changing the wheel difficult, especially in the case of a large spare wheel of a heavy-duty vehicle. 
     Repair and inflation kits are also used, to enable punctures to be repaired without removing the wheel. 
     Known kits comprise a sealing fluid canister; and a dedicated compressor connected to the canister. In the event of a puncture, the canister is connected by a hose to the tyre, and the dedicated compressor is turned on. 
     The compressed air injects the sealing fluid into the tyre, and inflates the tyre once the fluid increases in viscosity and seals the puncture. 
     Known kits normally feature a reciprocating dedicated compressor powered by an electric motor. Compressors of this sort are relatively noisy and bulky, especially those designed to inflate large, heavy-duty vehicle tyres. 
     Some, e.g. heavy-duty, vehicles are equipped with their own on-board air circuit, the air pressure of which, however, may not be suitable for injecting the sealing fluid, and may cause malfunctioning. More specifically, an on-board, heavy-duty vehicle air circuit comprises accumulators to maintain constant pressure and cater to sudden demand by actuating devices. When a repair unit, however, is connected to the air circuit, the high pressure causes hammering and surging, Which damage the unit; the small orifices of the valve closing the sealing fluid canister may cause clogging; and high pressure also causes premature polymerization of the sealing fluid, which may result in partial or complete clogging of the feed lines. 
     On the other hand, the high pressure of on-vehicle air circuits enables faster inflation of the tyre and, therefore, shorter hold-ups to carry out the repair. 
     DISCLOSURE OF INVENTION 
     It is an object of the present invention to provide a unit for repairing and inflating inflatable articles, designed to eliminate the above drawbacks. 
     According to the present invention, there is provided a unit for repairing and inflating inflatable articles, the unit defining a volume for containing a sealing fluid; an inlet and outlet connected fluidically to each other by the volume; and releasable fluidic connecting means for connecting the inlet to an outlet port of a vehicle air circuit comprising a pressure source and at least one actuator. 
     The repair and inflation unit also comprises a valve assembly located in series with the sealing fluid canister and designed to regulate the air input pressure to the canister. More specifically, the valve assembly is designed to operate selectively in a first operating configuration, in which the input pressure is reduced to a suitable injection value; and a second operating configuration, in which the input pressure to the canister is higher than in the first operating configuration of the valve assembly. 
     In other words, the input pressure to the sealing fluid canister is regulated, i.e. reduced, to achieve correct outflow of the sealing fluid from the canister to the tyre; and high pressure can be restored for faster inflation. 
     Moreover, the repair and inflation unit has no dedicated compressor, pressure being generated by a compressor already on the vehicle and mainly designed to control part of the vehicle, e.g. the brakes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  shows a view in perspective of one embodiment of the present invention; 
         FIG. 2  shows a fluidic diagram of the  FIG. 1  repair and inflation unit; 
         FIG. 3  shows a fluidic diagram of a further embodiment of the present invention. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Number  1  in  FIG. 1  indicates as a whole a tyre repair and inflation unit connectable to a vehicle air circuit comprising a compressed-air generator connected rigidly to a fixed structure of the vehicle. e.g. the frame; an actuator, e.g. a vehicle brake actuator; and an outlet port to which to connect unit  1 . 
     Unit  1  comprises a sealing fluid canister  8  connected to an inlet  9  for compressed air from the air circuit of a pressure source, such as the vehicle air circuit. 
     More specifically, canister  8  comprises a bottle  11 ; a dispenser unit (not shown) connecting inlet  9  to bottle  11 ; and a hose  12  connecting bottle  11  to a tyre. Bottle  11 , the dispenser unit, and hose  12  preferably define a single, replaceable unit, i.e. which is replaced when the bottle is empty or the sealing fluid is past its use-by date. 
     Canister  8  preferably comprises an internal valve (not shown) connecting inlet  9  fluidically to hose  12  via an inner volume  13  of bottle  11 , and may be made as described in International Patent Application WO-A1-2005084968 filed by the Applicant. 
     Unit  1  also comprises a pedestal  14  connected to canister  8  by releasable connecting means, e.g. a threaded connection or fast-fit coupling, and defining inlet  9 . 
     More specifically, the releasable connecting means are such that, when repairing and inflating the tyre, canister  8  is set to a substantially, though not necessarily, vertical operating position, in which hose  12 , connected to the dispenser unit of canister  8 , faces downwards and is interposed between bottle  11  and a supporting surface S on which pedestal  14  rests ( FIG. 1 ). 
     Pedestal  14  comprises a supporting body  15 , to which canister  8  is fitted; and a secondary body  16  connected rigidly to supporting body  15  and defining with it an annular recess  17 . 
     Pedestal  14  is substantially symmetrical with respect to a plane n (only shown partly in  FIG. 1 ), and secondary body  16  is smaller than the supporting body in a direction perpendicular to plane n. 
     Pedestal  14 —preferably supporting body  15 —defines two seats  18  adjacent to supporting surface S, and, in this non-limiting embodiment, but not exclusively for the purpose of the present invention, comprises two extractable arms  19  which withdraw inside seats  18 . Arms  19  are preferably symmetrical with respect to plane n, and define respective supports for pedestal  14  in a direction perpendicular to plane n. 
     Supporting body  15  is cylindrical, and defines annular recess  17  to house hose  12  connected to the dispenser unit of canister  8 . Accordingly, arms  19  are arc-shaped and hinged to respective peripheral portions  20  of supporting body  15 , so they are concentric with supporting body  15  when withdrawn. 
     Unit  1  also comprises a pressure regulating unit  29  mounted upstream from volume  13  to adjust the air pressure to bottle  11  to the best sealing fluid injection pressure. More specifically, the pressure regulating unit ( FIG. 2 ) comprises a selector valve  30 ; and a first and second regulating valve  31 ,  32  connected, parallel to each other, to selector valve  30 , and the respective outlets of which join up at a node  33  series connected to canister  8 . 
     Pressure regulating unit  29  is located in series between inlet  9  and canister  8 , and adjusts pressure discretely to achieve the best sealing fluid injection pressure, and the best tyre inflation pressure, as described in detail below. 
     More specifically, regulating valve  31  is an air resistance that produces a pressure drop to reduce the pressure of node  33  and canister  8  to a suitable pressure to inject the sealing fluid from bottle  11 . 
     Regulating valve  32  is a second air resistance which, between its inlet and outlet, produces a smaller pressure drop than regulating valve  31 , so that, when selector valve  30  directs compressed airflow to regulating valve  32  and closes off access to regulating valve  31  (the opposite configuration to the one shown in  FIG. 2 ), the airflow pressure at canister  8  is higher than when selector valve  30  directs airflow to regulating valve  31  and closes regulating valve  32  ( FIG. 2  configuration). 
     In a preferred embodiment, each regulating valve  31 ,  32  is a non-return valve comprising a shutter, and a spring pressing the shutter into the closed position. To operate as described above, the spring of regulating valve  31  has a greater modulus than the spring of regulating valve  32 . 
     In another preferred embodiment of the present invention, the modulus of the springs of regulating valves  31 ,  32  can be user-adjusted, preferably manually. 
     Unit  1  also comprises a display device for showing the user when injection is completed, i.e. when the sealing fluid in bottle  11  runs out, and inflation can begin. In a preferred embodiment of the present invention, the display device is passive, and comprises a tube, the wall of which has at least one portion made of transparent or semitransparent material, so the user can see whether or not there is sealing fluid flowing along the tube. The tube defines hose  12 , and, during use, the display device enables the user to check continued flow of sealing fluid along hose  12 . When the display device shows no flow of sealing fluid along hose  12 , the user may switch selector valve  30  to direct compressed airflow to regulating valve  32 . Selector valve  30  preferably comprises a knob  35 , and has a rotary shutter connected to knob  35 , which the user turns to switch the selector valve. 
     To check tyre pressure during inflation, unit  1  comprises a gauge  36  located between inlet  9  and a ring nut  37  connected to hose  12  and which screws onto the safety valve of the tyre. Gauge  36  preferably picks up the pressure signal along a line  38  connecting node  33  to canister  8 . 
     Unit  1  comprises a second hose  40  parallel to canister  8  with respect to inlet  9 . Hose  40  receives compressed air directly from inlet  9 , and serves solely to inflate the tyre when checking tyre pressure. Accordingly, hose  40  is also connected to a gauge; and gauge  36  is preferably connected to both line  38  and hose  40  by an OR fluidic selector  41 . 
     Unit  1  also comprises a second selector valve  42  for selecting a repair path, in which inlet  9  is connected to canister  8 , or an inflation-only path, in which inlet  9  is connected to hose  40 . 
     Unit  1  also comprises a pressure reducer between inlet  9  and hose  40 , so pressure can also be reduced when checking tyre pressure, as opposed to repairing the tyre. 
     For example, the pressure reducer is a continuously-adjusted valve defining a variable air resistance along hose  40  by constriction. Starting with the valve in the closed position, the user can increase tyre pressure by gradually relieving the constriction. A spring may also be provided to restore the pressure reducer to the closed position when pressure is no longer being regulated by the user. 
     In a preferred embodiment, the pressure reducer is incorporated in selector valve  42 , which is a continuously-adjusted valve, at least as regards opening and closing hose  40 . 
     Clearly, changes may be made to the unit for repairing and inflating inflatable articles as described and illustrated herein without, however, departing from the scope of the present invention as defined in the accompanying Claims. 
     For example, regulating valve  32  may be eliminated, and regulating valve  31  is located parallel to a bypass line  43  which produces no significant pressure drop between selector valve  30  and node  33 . 
     Two dedicated gauges may also be provided, one connected between selector valve  42  and ring nut  37 , preferably between node  33  and canister  8 , and the other connected to hose  40 , downstream from selector valve  42 . 
     Arms  19  may be connected differently to move between a withdrawn and extracted position, e.g. may be straight and slide along runners defined by pedestal  14 . 
     Hose  40  and selector valve  42  may be eliminated, in which case, inlet  9  is connected to canister  8  solely by pressure regulating unit  29 . 
     Node  33  may also be located downstream from inner volume  13 . In which case, bypass line  43  is connected to hose  12  downstream from canister  8 . In this case, too, compressed airflow can be directed by selector valve  30  both through regulating valve  31  and through regulating valve  32  or bypass line  43 . As in the previous example, regulating valve  32  produces a lower pressure drop than regulating valve  31 , or is eliminated, so the pressure along bypass line  43  is higher than the input pressure to canister  8 , and compressed air flows faster along bypass line  43 . On the other hand, a relatively low pressure to canister  8  improves outflow of the sealing fluid, and reduces the likelihood of the fluid coagulating.