DEVICE FOR HEATING WATER JET OF MOTOR VEHICLE WINDSCREEN WIPERS, BY MEANS OF A SURFACE HEAT EXCHANGER

Abstract: The heat exchanger is made up of two coaxial tubes (1, 2), positioned one inside the other, so that an airtight hollow space is formed. Hot water which comes from the engine passes through the internal tube (1) and the windscreen wiper liquid passes through the hollow space in such a way that this can be heated as it comes in contact with the walls of the most inner tube (1), heated in its turn by the high temperature water which passes through it.

Description: "DBVICϋ. FOR HώATING WATER J≤T OP MOTOR VEHICLE WIITDSCRBUN WIPSRS, BY MfiANS OP A SURFACE HEAT EXCHANGER" DESCRIPTION TEΣT This application for a patent for an industrial invention concerns a device for heating the water jets of motor vehicle windscreen wipers, by means of a surface heat ex changer. The problem, which thanks to the device at reference should be solved, concerns the efficient external cleaning of the front windscreen of motor wehicl s. Λs is well known,safe driving mostly depends on this, as it results in perfect visibility. At present, ail modern motor vehicles are equipped with a device to spray water at normal temperature onto the wind¬ screen; by means of the windscreen wipers, this water cast remove mud, dust or similar elements perfectly. However in at least two cases, tin ' s combined action does not give the desired results, in as much as it does not permit efficient external cleaning of the windscreen. This happens whenever a layer of j co is formed on the windscreen, during the winter season of course, or when, while driving, many smal l insects are squashed onto the windscreen itself, leaving a compact layer of grease on it. In fact, in both cases it is necessary to intervene with the use of hot water, which not only melts the layer of ice immediately but also dissolves the film of grease formed on the windscreen, thus leaving the windscreen per¬ fectly transparent ;ι ( ', r a i n. Up to the present, similar interventions were only possi¬ ble with the vehicle at a standstill, by resorting to a container of previously heated water, given the fact that no motor vehicles have ever been pjrovided with the possi- bility of spraying high temperature water onto the wind¬ screen. In actual fact, it must bo said that some rather empiri¬ cal attempts which are in any case not very convincing, have been made in order to obtain the heating of the water jets of windscreen wipers. These attempts mostly consisted in inserting a heating element inside the special tanks, in order to raise the temperature of the water contained therein, to be sprayed onto the windscreen subsequently. The application of this element however would not seem to be entirely convincing sinc , besides creating problems of installation, i t can- resent considerable problems concern¬ ing the electrical input to the battery, so as to cause an unbalance in the motor vehicles eLectric equipment. On the other hand, the device according to the invention, is intended to obtain the heating of the water jets of windscreen wipers, in an extremely practical, functional and above all economical manner, without interferring in the slightest with the technical characteristics of the wehicle. In fact, the device makes use of a surface heat exchanger to be applied either to the tube which conducts the hot water from the engine to the cooling radiator or to the tube which brings the hot water from the engine to the small radiator of the internal air-conditioning system, indifferently. This heat exchanger is made up of two tubes, one inside the other, so that an airtight hollow space is created between the two. The most inner tube of the heat exchanger must be con- nected at both ends to the water tube which goes from the engine to the radiator. The latter tube should be inter¬ rupted and the exchanger itself inserted at the cut off ends, so that water can flow inside it. The abovementioncd hollow space of the exchanger is in contact with the outside by means of two small tubes in which are inserted: in one, the duct which brings the li¬ quid for cleaning the windscreen from the tank to the ex¬ changer, in the other, the small tube which starts from the exchanger and conducts this liquid to the spray nozzle on the windscreen. In this device, the hot water from the engine, by passing through the most inner tube of the exchanger, ensures the heating of the walls; the Liquid for cleaning the wind¬ screens comes into contact with these walls while passing through the hollow space and is heated in its turn, so as to be able to reach the spray nozzle and therefore the actual windscreen, at a temperature which is high enough to melt any layer of ice or film of grease. In order to explain more clearly, the description of the invention continues with reference to the drawing attacι ed, shown merely for illustration purposes, and not re- !-" strictive, in which Figure 1 is a section of the device ' according to the invention with partial representation of the inlet and outlet tubes. W th reference to the attached figure, the invention is made up of an inner tube ( 1 ) with two nozzles at the ends on which the cut off ends of the duct through which the hot water flows, are inserted and tightly fastened by means of normal hose clips. On the outside of the tube (l) in a coaxial position, a tube (2) is inserted, so as to create a thin airtight hoi. lo space which must be crossed by the water feeding the spray nozzles. The water enter.s and goes out of two noz¬ zles placed at the two ends of the tube itself (2). The cut off ends of the duct which takes the water from the tank to the windscreen are inserted and clamped to these nozzles.

Claims: Claims 1) Device for heating the water jets of motor vehicle windscreen wipers, by means of a surface heat exchanger, characterised by the fact that it is made up of an inner tube equipped with two nozzles on the ends, to be connect ed to the cut off ends of a duct to the engine through which hot water flows. On the outside of this tube in a coaxial position, a second tube is inserted so as to form an airtight hollow space through whicli the liquid for cleaning the windscreens must pass. The liquid goes in and out by means of two nozzles placed near the ends, to which the cut off ends of the duct which takes the water for cleaning the windscreens from the tank to the windscreen is connected.

Inventors: BALDONI OTELLO, SALVUCCI SANDRO, BALDONI, OTELLO, SALVUCCI, SANDRO
Applicants: BALDONI OTELLO, SALVUCCI SANDRO, BALDONI, OTELLO, SALVUCCI, SANDRO
Application year: 1986
Main classification: B60S1
IPC codes: B60S1