FR2853636A1 - Safety device for concrete caisson, has elastic cables fixed to base of caisson and passed in sheaves at corners of caisson, where cables provides total stress of three hundred kilogram when safety net is at bottom of caisson - Google Patents

Abstract

The device has a safety net (2) that comprises a dimension equal to an inner dimension of a concrete caisson (1). A set of sheaves (4) having five grooves are fixed in four corners of the caisson. Four set of five elastic cables (3) fixed to base of the caisson and passed in the sheaves are fixed on the net. The cables provide total stress of 300 kilogram when the net is at the bottom of the caisson.

Description

i

  The present invention relates to a safety device by net of concrete boxes for buried household waste containers.

  When emptying the buried containers, the crane truck having removed the mobile box from its pit, user safety must be guaranteed.

  There are currently several systems providing this security.

  The most common is a movable floor that rises to ground level using counterweights or a pantograph system powered by gas cylinders.

  There is also a pivoting floor system with spring damping on the market.

  The device according to the invention ensures the safety of the user during the emptying maneuver using a net.

  The accompanying drawings illustrate the invention.

  Figure 1 shows in perspective the concrete box with the safety net in the high position.

  With reference to these drawings, the device comprises a safety net 2 which is the internal dimensions of the concrete box 1.

  In the four corners of the concrete box 1 are fixed a set of sheaves with five grooves.

  Four sets of five elastic cables 3 with a diameter of 8 mm fixed to the base of the concrete box 1 and passing through the sheaves 4 are fixed to the safety net 2.

  Taking into account the dimensions of the concrete box 1, the elongation of the elastic cables 3 is 87% when the safety net 2 is at the bottom of the concrete box 1.

  The tension by each elastic cable 3 in this elongated position is then 15 kg.

  The total tension of the twenty elastic cables 3 when the safety net 2 is at the bottom of the concrete box 1 is therefore 300 kg distributed, which allows the damping of an accidental fall of a person during the emptying operation.

  The empty weight of the mobile household waste container being approximately 800 kg allows it, when it is put back in place, to counteract the resistance of the 4 sets of elastic cables 3 and to allow it by its dead weight of 30 down to the bottom of the concrete box 1.

  The device according to the invention is particularly intended for the safety of buried household waste containers.

Claims (4)

  1) Safety device with a net of concrete boxes for buried household waste containers, characterized in that it comprises a safety net 2 which is the internal dimensions of the concrete box 2.   2) Device according to claim 1 characterized in that in the four corners 5 of the concrete box I are provided with five sheaves which receive the elastic cables 3 fixed to the bottom of the concrete box 1 and to the safety net 2.   3) Device according to claims 1 and 2 characterized in that the total tension of the elastic cables 3 when the safety net 2 is at the bottom of the concrete box 1, an extension of 87%, is 300 kg allowing the damping 10 accidental fall of a person into the concrete box 1 during the emptying operation.   4) Device according to claim 3 characterized in that the empty weight of the mobile household waste box is greater than the total tension of 300 kg of the twenty elastic cables 3 allowing it to descend naturally 15 to the bottom of the concrete box 1