Abstract:
Turning arrangement ( 2 ) for concrete products, paving stones/flagstones for paving, curb stones for delimiting and blocks for erecting walls are arranged in a row with uniform orientation ( 4 ), the products ( 4 ) are advanced to a turning arrangement where the individual concrete product ( 6 ) is turned by the force of gravity.

Description:
This application claims the benefit of Danish Application No. PA 2004 01819 filed Nov. 22, 2004 and PCT/DK2005/000743 filed Nov. 22, 2005, which are hereby incorporated by reference in their entirety. 
   The present invention concerns equipment for turning concrete products with rectangular shape. 
   Concrete products may e.g. be paving stones, small flagstones, curb stones or blocks for erecting walls. The concrete products may furthermore be artificially aged, often termed rumbled, broken or other kinds of finishing treatment. In the following, product refers to these groups. 
   The products are to be turned for different reasons. In some cases, the products are made in moulds so that the side with the largest relative area face upwards and downwards, respectively. In order to stack the products rationally, with regard to the subsequent process it may be expedient to have the products facing in a certain direction. They may also have to be turned in order that the other sides of the products are exposed to the surroundings, e.g. in connection with hardening, surface treatment such as impregnation, painting or similar, or by visual quality control. 
   There are a number of proposals for solving this task, see e.g. U.S. Pat. No. 421,385, where a first belt conveys the products, after which an belt disposed edgewise in parallel with the first belt turns the products so that the products come to rest upon a second surface. A similar principle is utilised in JP-A-08188230, where the products on a first belt are brought past a ramp partly overlapping the belt, so that the products are partly sliding on the slide. Due to the shape of the slide, the products are forced over on a second side face. 
   The prior art equipment for turning products is thus relatively complicated, as there are a plurality of interacting components (belts, slides and the like). This means that the equipment is in danger of interruption of the production. In connection with equipment with a turning belt as known from U.S. Pat. No. 421,385, this may occur in that a product is jammed between the two belts, whereby the products may fall down, the belt breaks, or the control of the relative speed of the two belts cause inexpedient accumulation of products on the belt. By the slide solution, the slide is in danger of acting as a stop for the products on the belt, whereby an accumulation of products occurs on the belt, or/and these fall off the belt. 
   The present invention thus presents a new and inventive equipment which does not have these drawbacks but solves the problem by means of a reliable and mechanically uncomplicated equipment. 
   The block turning arrangement receives a number of uniformly oriented, identical products, turning these products one quarter of a revolution about the longitudinal axis by means of the action of the force of gravity on the conveyed product. 
   When products have been arrayed in a row and are uniformly oriented on a conveyor system, there are numerous systems for orienting and arraying, and sometimes it may be suitable or desirable that these uniformly oriented products are turned one quarter of a revolution to utilise a possible stacking equipment more optimally, or to enable inspection of the product from several angles, or to enable stacking of the products at all. 
   The products typically emerge from an artificial ageing process, called a rumbling process, with subsequent arranging and aligning of the products, typically resting on their broadest surface. It may then be suitable that the products are raised subsequently, i.e. turned one quarter of a revolution so that they are conveyed on their narrowest surface. 
   Alternatively, the products may come from splitting, a breaking process, of the products, by which the cutting produces one or more fractured surfaces, after which it may be suitable to turn the products so that the fractured surfaces are uniformly oriented. This requires that one product is turned twice a quarter of a revolution, or that each half is turned one quarter of a revolution, each their way. 
   The turning arrangement functions in that the product to be turned is pushed out upon a support rail which is narrower than the downwards facing surface of the products, and when the product leaves the support, which is provided in the entire width of the product, the product will turn over by means of the force of gravity and be caught by a running belt under the narrow support rail. The distance from the narrow rail and down to the conveyor system down under is adapted to the height of the turned product. 
   In its simplest form, the turning arrangement operates by advancing the products in a long row with the products oriented uniformly, either lying or standing, the individual products in turn being pushed out on the turning means by the conveyor system, the turning means having a rail at one side which is narrower than half the downwards directed face on the product. When the product leaves the transporting system, the product is only supported on less than half of the downwards directed surface, and will therefore turn over and away from the support rail by means of the force of gravity. Under the support rail there is a second transporting system which simultaneously with operating as a gripper/collector further conveys the product out of the turning means. This transporting arrangement is disposed at a height that allows the product to fall down and turn it one quarter of a revolution. In order to ensure that the product does not continue its rotation and continues turning, there is provided a guide rail which catches the product and together with the above mentioned support rail forms a channel, so that the product cannot turn any more, the width of the channel is slightly greater than the new downwards directed surface of the product. 
   Additional preferred embodiments are defined in the dependent claims. 
   The invention will now be explained in more detail with reference to the drawings, on which: 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1A  shows a perspective view of a product turning means according to the invention in its simplest embodiment; 
       FIG. 1B  shows the turning arrangement itself, where one side plate is removed for the sake of clarity; and 
       FIGS. 2A to 2C  show in principle turning of the product in three steps. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   On  FIG. 1 , the turning arrangement ( 2 ) appears, where the transporting system ( 12 ,  14 ,  16 ) is shown as belt conveyors with guide rails ( 30 ) guiding the product ( 8 ,  10 ) into and out of the turning arrangement. 
   The support rail ( 18 ) on  FIG. 1B  is here shown in a form where the product ( 4 ) is supported in its full width over the first length with a carrier plate ( 20 ); this is for preventing the product ( 6 ) from tipping down on the reversing roller ( 13 ) upon its turning in the arrangement ( 2 ) on the first conveyor belt ( 12 ). The support rail ( 18 ) then narrows to be narrower than half of the downwards directed surface on the product ( 26 ). This ensures that the product ( 6 ) by means of the force of gravity tilts down upon the transporting arrangement ( 14 ) provided in the turning arrangement. Opposite the support rail, a guide rail ( 22 ) is provided, not shown on  FIG. 1B , ensuring that the product is caught and does not turn any further due to its inertia. This guide rail ( 22 ) together with the underside of the support rail ( 24 ) form a channel that allows the product to be caught and advanced in the turning arrangement on the now downwards directed surface ( 28 ). Then the product ( 6 ) continues over onto the third transporting arrangement ( 16 ). 
   On  FIG. 2A  appears a product on its way into the turning means ( 4 ). The product is conveyed by a conveyor belt ( 12 ) and is pushed out upon a support rail ( 18 ) which is narrower than the downwards directed surface ( 26 ) of the product. With regard to the transporting system shown here, the first part of the support rail ( 18 ) may be designed as a carrier plate ( 20 ) in the fall width of the product in order to prevent that the product ( 4 ), when becoming overbalanced by means of gravity, turns/tilts down onto the reversing roller ( 13 ) of the first conveying system ( 12 ) 
   On  FIG. 2B  appears a product in the turning arrangement, where it is half turned ( 6 ), the next product ( 4 ) is furthermore on its way into the turning arrangement ( 2 ) as it has functioned as a pusher for the now turning product ( 6 ). 
   On  FIG. 2C  appears the turned product ( 6 ) in the turning arrangement ( 2 ), the next product ( 4 ) is still on its way into the turning arrangement ( 2 ) while at the same time the now turned product ( 6 ) is conveyed out of the turning arrangement ( 2 ) of the transporting system in the turning means ( 14 ) and onwards to the next transport arrangement ( 16 ) conveying the product on to packing, further turning or control arrangements or otherwise. 
   LIST OF REFERENCE NUMBERS 
   
       
         2 . Block turning arrangement 
         4 . Product on its way into the turning arrangement 
         6 . Product in the turning arrangement, just turned 
         8 . Product on its way into the turning arrangement 
         10 . Products on their way away from the turning arrangement 
         12 . Transporting system before the turning arrangement 
         13 . Reversing roller for the transporting system 
         14 . Transporting system in turning arrangement 
         16 . Transporting system after the turning arrangement 
         18 . Support rail 
         20 . Carrier plate 
         22 . Guide rail in turning means 
         24 . Support plate in turning means under support rail 
         26 . Downwards directed surface on product before turning 
         28 . Surface which after turning becomes downwards directed 
         30 . Guide rails for products before and after the turning arrangement