Dowel device for a concrete machine and concrete machine equipped with such a dowel device

Abstract

Improved dowel device for a concrete machine which mainly consists of a series of insertion elements ( 19 ) for dowels ( 3 ) which is provided with an output pipe ( 27 ) for dowels ( 3 ) at the bottom, and a push-out mechanism ( 30 ) for dowels ( 3 ) whereby the push-out mechanism ( 30 ) of each insertion element ( 19 ) is formed of a chain ( 31 ) which is guided over two chain wheels ( 32 - 33 ) placed on top of one another and a flexible blade ( 34 ) which is fixed to the chain ( 31 ) with one far end and which is provided with a pressure piece ( 37 ) on the other far end, whereby the blade ( 34 ) is guided over a guide at the bottom of the second compartment which bends off the blade ( 34 ) in the direction of the output pipe ( 27 ).

1 . A dowel device for a concrete machine including a mobile chassis to which the dowel device is or can be fixed, the dowel device having a width relative to a movement direction of a concrete machine to which it may be fixed, and comprising a series of insertion elements for dowels which are erected widthwise in relation to the dowel device at a distance from one another, and further comprising a housing directed upward, said housing having a first compartment in which dowels can be stacked and an output pipe for dowels at the bottom of said first compartment, and a second compartment in which a push-out mechanism for dowels is provided, and wherein both compartments are connected at their respective bottoms via a passage, said push-out mechanism of each insertion element comprising a chain which is guided over two chain wheels disposed one above the other and a flexible blade which is fixed to the chain and having one far end and which is provided with a pressure piece on another far end, and wherein the blade is guided over a guide at the bottom of the second compartment, said guide configured to bend off the blade through said passage in the direction of the output pipe.  
   
   
       2 . The dowel device for a concrete machine according to  claim 1 , wherein one of the chain wheels is provided with a drive to move the pressure piece of the push-out mechanism at least between a first extreme position in which the blade and the pressure piece are entirely withdrawn from the second compartment and a second extreme position in which the blade extends into the first compartment with a pressure piece up against or practically against the output pipe.  
   
   
       3 . The dowel device for a concrete machine according to  claim 2 , wherein the extreme positions of the push-out mechanism are determined by a stop block which is fixed to the chain and two stop-forming elements working in conjunction with it.  
   
   
       4 . The dowel device for a concrete machine according to  claim 1  wherein the top chain wheels of the insertion elements are provided on a common shaft which is driven by a common drive.  
   
   
       5 . The dowel device for a concrete machine according to  claim 2 , wherein the drive is electrically connected to a control box arranged such that when the drive is activated for pushing out the dowels, the speed at which the dowels are pushed out of the insertion elements is equal or practically equal to the driving speed of a concrete machine to which the dowel device is fixed.  
   
   
       6 . The dowel device for a concrete machine according to  claim 1 , wherein the configuration of the pressure piece is such that it can hold a dowel at its far end.  
   
   
       7 . The dowel device for a concrete machine according to  claim 1 , wherein the blade is made of spring steel.  
   
   
       8 . The dowel device for a concrete machine according to  claim 1 , wherein the dowel device is provided with an automatic loading system for loading the dowels in the insertion elements.  
   
   
       9 . The dowel device for a concrete machine according to  claim 8 , wherein the loading system comprises a trolley with a bottom slanting down widthwise and a groove-shaped outlet for the dowels, which trolley can be moved to and fro, widthwise on the bottom of a tray or guiding gutter which is fixed or can be fixed to a concrete machine and onto which the insertion elements are fixed, each time under a groove in the bottom through which the insertion element can be loaded.  
   
   
       10 . The dowel device for a concrete machine according to  claim 8 , wherein in each insertion element is provided a valve at the top which is arranged to receive a dowel which falls from the trolley in the respective insertion element and which can subsequently drop this dowel in a controlled manner in the respective insertion element.  
   
   
       11 . The dowel device for a concrete machine according to  claim 10 , wherein the valve is a stop valve which seals the insertion element at the top.  
   
   
       12 . The dowel device for a concrete machine according to  claim 10 , wherein the valve is formed of an angle section with legs which is hinge-mounted around a shaft in its longitudinal direction and which is hinge-mounted between a position in which the first compartment is sealed by means of one leg and a second position in which this leg is tilted downward and the other leg seals the first compartment.  
   
   
       13 . The dowel device for a concrete machine according to  claim 12 , wherein the valve is provided with a control element which is arranged to work in conjunction with the trolley so as to move the valve between said extreme positions when the trolley is moved over the respective insertion element.  
   
   
       14 . The dowel device for a concrete machine according to  claim 13 , wherein the control element is formed of a lip which is fixed to the valve in such a manner that, in the first position of the valve, it rests on the bottom of the tray, and in the second position of the valve it is directed upward and extends above the bottom of the tray so as to be able to work in conjunction with the trolley.  
   
   
       15 . The dowel device for a concrete machine according to  claim 14 , wherein the trolley is equipped with an element which moves over or right above the bottom and which can work in conjunction with the control element.  
   
   
       16 . The dowel device for a concrete machine according to  claim 15 , wherein the element is a key-shaped element on which the inclined bottom of the trolley rests.  
   
   
       17 . A concrete machine, comprising a dowel device according to  claim 1.