Patent Publication Number: US-9415427-B2

Title: Machine for working a surface with a high-pressure water jet

Description:
AREA OF THE INVENTION 
     This invention relates to a machine for working a surface with a high-pressure water jet, comprising a mobile chassis with a boom that carries a lance with a water jet ejecting nozzle, and a drive unit that comprises a motor and control units for the chassis and the boom. 
     BACKGROUND OF THE INVENTION 
     A machine of this type is known from, for example, SE 525915 and is used for working a surface layer of concrete, especially the surface layer on concrete is bridges so that a new surface layer can be poured. The surface layer gradually acquires cracks and the surface layer must be renewed before salt from the winter salting reaches down to the uppermost reinforcing layer. The machine can also be used for vertical surfaces. 
     GOAL OF THE INVENTION 
     The invention has the purpose of creating greater safety also when using it on vertical surfaces and roof surfaces with a machine adapted chiefly for horizontal surfaces. 
     SHORT DESCRIPTION OF THE INVENTION 
     The purpose of the invention is met when the chassis comprises an underframe and a carrier unit shiftably mounted on the underframe, which carrier unit carries the boom and the drive unit so that the machine&#39;s centre of gravity can be shifted by shifting the carrier on the underframe. The invention is defined by the claims. 
    
    
     
       SHORT DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a lateral view of an example of a machine in accordance with the invention. 
         FIG. 2  is a perspective view of the same machine in another work position. 
         FIG. 3  is a front view corresponding to  FIG. 2 . 
         FIG. 4  is a partially open detailed view of  FIG. 1 . 
         FIG. 5  is a lateral view in the work position shown in  FIG. 2 . 
         FIG. 6  is a perspective view of a traveling cart carrying a nozzle for ejecting a water jet. 
     
    
    
     DESCRIPTION OF THE SHOWN EXAMPLE OF THE INVENTION 
     The machine shown in the figures has a mobile chassis  11  with caterpillar tracks  12 ,  13 . The chassis carries a boom  14  that carries in a universally flexible manner a working unit  15  of the type shown and described in SE525915 and therefore not described and shown in detail here. The working unit comprises a feeding beam  16  and a traveling cart  20  mounted on the latter. 
     The traveling cart  20  and the feeding beam  16  are shown separately as  FIG. 6 . The traveling cart  20  has a hydraulic motor  21  that drives the carriage out along the feeding beam with a cogwheel engaged with a rack on the feeding beam. The traveling cart carries a lance  22  that comprises a nozzle  23  for ejecting a water jet and is coupled to an external pump for high-pressure water for producing a collected, laminar, working water jet with supersonic speed. A hydraulic motor  24  is constructed together with a bearing housing  25  for oscillating the lance  22  by a crankshaft about an axis II in a plane at a right angle to the direction of movement of the traveling cart in order to produce a wider working track. A hydraulic motor in the form of a hydraulic cylinder  26  (a pivoting device  26 ) is coupled to pivot the lance  22  together with the motor  24  and the bearing housing  25  about an axis I that is at a right angle to the traveling cart, that is, to pivot the lance in a plane parallel to the feeding beam in order to be able to give the lance an angle of attack. The lance extends down into a protective hood  28  ( FIG. 1 ) that holds broken-off concrete and water within the housing. 
     The chassis  11  has an upright console  29  with a rotatable holder for the boom  14  so that the boom can be rotated in a plane across the chassis. The inner part  30  of the boom has an extensible part  31  and the boom has an outer part  32  that is rotatably fastened in the inner part of the boom and carries the working unit  15 . The hoses for connecting high-pressure water and hydraulic oil are not shown but a steel spiral  40  for protecting the water connection and steel spirals  41 ,  42  for protecting the hydraulic hose connections are shown. 
     The chassis  11  has an underframe  33  with caterpillar tracks  12 ,  13  and an upper part, a carrier unit  34  that carries the console  29  and a drive unit  35  that comprises a motor and control units for the chassis and the boom. The upper part  34  of the chassis runs in longitudinal guide rails  36 ,  37  on the underframe  33 , which can be best seen from  FIG. 3 , and the upper part can be shifted by a motor on the lower part by a hydraulic cylinder  38  coupled between the upper part and the underframe, as is apparent from  FIG. 4 .  FIG. 4  shows the position in  FIG. 1  and it is a detailed image from  FIG. 1  in partial longitudinal section for showing the hydraulic cylinder  38 . 
       FIG. 1  shows the machine in position for working a horizontal surface, for example, a bridge deck. In this position the machine is not balanced in the longitudinal direction with respect to the caterpillar tracks but rather its centre of gravity is located closer to the console  29  so that the machine becomes balanced in operation since the force of the reaction from the water jet then creates a significant lifting force on the boom. 
       FIGS. 2, 3 and 5  show the machine in position for working a vertical surface. In this case the hydraulic cylinder  38  is instead contracted so that the upper part  34  of the chassis becomes shifted on the underframe  33 , as is shown in the figures. As a result thereof, the machine becomes more balanced in the longitudinal direction when vertical surfaces or, e.g., roof surfaces in a tunnel are to be worked so that the machine becomes stable even for these job tasks. This brings it about that the risk of the machine overturning is reduced.