A SCREEN ADAPTED TO BE PLACED IN FRONT OF A HEARTHFIRE OR OTHER SOURCE OF RADIANT HEAT

Abstract: A screen is provided for heating a room by convecti­ on using the heat from a radiation heat source, e.g. an open hearth fire, a gas-fire or an electric radiant heater, and when the heat source is an open hearth fire for use as a fire-guard preventing sparks or other small particles of combustion from entering the room in which the fire is located. The screen includes a row of at least with their upper portions spaced apart vertical pipes having each at or near their lower end an inlet opening and at or near their upper end an outlet opening for air sucked from the room by the chimney-action of the warm pipes. The pipes of at least one pair of adjacent pipes of the screen are hingedly inter­ connected for the rotation of one of these pipes about the longitudinal axis of the other pipe thereof by coupling and clamping means.

Description: The invention relates to a screen adapted to be placed in front of a hearth fire or other source of radiant heat, said screen comprising a row of interconnected, at least for a part of their length horizontally spaced apart round pipes which extend vertically, are placed side by side and have each at or near their lower end an opening to admit air from and at or near their upper end an opening to discharge air into the room to be heated by said source of heat, the two pipes of at least one pair of adjacent pipes of said screen being so interconnected by a hinge joint, as to ensure that one pipe of said pair is adapted to swing with its longitudinal axis in a circular cylinder surface about the longitudinal axis of the other pipe of said pair, said hinge joint consisting of a coupling member in one piece of material including two end portion, of which each one embraces an individual pipe of said pair, an intermediate portion interconnecting said end portions and a connecting means so acting on the connection between said end portions of the coupling member and the pipes extending therethrough as to guarantee that in the active end condition said connecting means one end portion of the coupling member is firmly connected to one pipe, but the other end portion embraces the other pipe in a manner as to allow still a relative rotation of said end portion and said other pipe. A screen of this construction has been disclosed in the European patent specification EP-B-0123342. In the embodiments shown in Figs. 3 and 4 of this patent specification the one piece coupling members are connected firmly with one pipe of the respective pair of pipes, which is only possible by means of a fastening screw or a shrunk connection. However, the thickness of the wall of the pipes is so small (some tenths of a millimeter) that the fixing by means of a screw leads to serious damage of the pipe and the fixing by shrinking requires a pipe with a considerable greater thickness of its wall. It appears that these known one piece coupling members require much time and care to apply between adjacent pipes of the screen. The invention has the object to provide for a screen of the above described kind an improved hinge joint, of which the coupling member can be manufactured and fitted in a very simple and cheap way and does not affect the pipes in any unfavourable manner, so that pipes with the smallest possible wall thickness, that means very light pipes, may be used. This is of great importance, since fire screens consisting of pipes are comparatively heavy articles. According to the invention this is achieved in that said coupling member in one piece of material so includes two end portions, each of which is in the shape of a splitted ring and embraces the pipe in question of said pair through an angle of more than 180° but less than 360°, and a connecting means consisting of two connecting parts interconnecting in pairs the ends facing each other of said splitted rings, as to form together an endless closed loop, and further in that the connecting menas is a clamping means adapted to force said connecting parts one towards the other. This coupling member can be constructed in several ways. When, for instance, the splitted ring parts of the coupling member are in the condition, in which they are unloaded by the clamping means and then have slightly different diameters, the clamping means engaging the connecting parts may be placed midway between said ring parts. Tightening of the clamping means then clamps the splitted ring having the smaller diameter firmly on one pipe whereas the other splitted ring still embraces the other pipe with some clearance so that it remains rotatable about said latter pipe. On the other hand, it is also possible to use a coupling member, of which the splitted rings, when being unloaded by the clamping means, have equal diameters. In that case the clamping means are so placed, as to engage the connecting parts of said member nearer to one than to the other ring part of said member. It will be obvious that tightening of the clamping means will have the same effect as in the first possibility. One pipe will then be firmly clamped and the other one will be left rotatable in its ring part. The coupling member for such a hinge joint in the shape of an endless closed loop of strip material can be made in mass production in a simple and cheap manner, if in the first place a tube with suitable wall thickness and a cross-section in the shape of the required endless closed loop of the coupling member, when in its unloaded condition, is formed and thereafter, in the next or the opposite order of succession, holes for at least one clamping bolt or screw per coupling member are made in the portions of said tube meant for the connecting parts and thereupon pieces, of which the width corresponds with the height of the loop of the coupling member, are cut from said tube. This method can be carried out in continuous working with great speed. The said tube may be drawn through one or more moulds with suitable openings and mandrels or be extruded, but it is also possible for that purpose to start with a tube having a cross section of standard profile, for instance a circular profile, and to roll said tube till the cross-sectional profile has attained the desired shape. It is observed that from Figs. 5 and 6 of the mentioned European patent specification EP-B-0123342 coupling members for the said hinge joint are known which, after being mounted, have the shape of an endless closed loop consisting of two splitted rings interconnected by two connecting parts which are adapted to be forced one towards the other by a clamping means. However, these known coupling members are not formed from one piece of material, but they consist of two individual parts each of which includes a splitted ring and portions of the two connecting parts, which are interconnected in pairs by the clamping screws or bolts to form the connecting parts. These known hinge joint appear to require for their manufacture and assembly relatively much material, much working hours and considerable accuracy and to be, as a result thereof relatively costly. The invention will hereafter be further elucidated with the aid of the embodiments shown in the accompanying drawing. In the drawings: Fig. 1 is a front view of a portion of a screen, of which the pipes of a plurality of pairs of adjacent pipes are hingedly interconnected in the way according to the invention, Fig. 2 is on an enlarged scale a cross-sectional view of the pipes of such a pair and a top view of the coupling members which hingedly interconnects said pipes, and Fig. 3 is a cross-sectional view and a top view as shown in Fig. 2 of pipes and a variant of the coupling member, respectively. Fig. 1 shows four hingedly interconnected, round vertical pipes 1,2,3,4 of a screen according to the invention, said pipes having each near the lower end an inlet opening 5 and near the upper end a discharge opening 6. The hinge joint between the two pipes of each pair of directly pipes consists of a coupling member 7 and a clamping means in the shape of a self-tapping screw 8. The coupling member 7 is formed as shown in Fig. 2. This coupling member consists of a closed endless strip in one piece which is thick in comparison with the very small wall thickness of the pipes and has the shape of a first ring part 9 always embracing the left hand pipe of a pair of pipes through an angle of about 300°, a second ring part 10 and connecting parts 11,12 which interconnect in pairs the ends of said ring part 9,10. The clamping screw 8 is passed through a loosely fitting hole of the connecting part 12 and screwed in an originally too narrow hole of the connecting part 11. In Fig. 2 as well as in Fig. 3 the clamping screw 8 has not yet been screwed on. In this unloaded condition of the coupling member 7 the inner diameter of the left hand ring part 9 is equal to or slightly larger than the outer diameter of the upper portion of the pipes, of which the lower portion has a larger diameter. Thus the coupling member 7 is only just adapted to be slid with said ring part 9 on said upper portion of the pipes. In unloaded condition the right hand ring part 10 has an inner diameter which is larger than that of the left hand ring part 9, due to which the ring part 10 has a fit with noticeable clearance on the upper pipe portion. When the coupling member 7 has been slid on two pipes extending side by side, the wider lower most pipe portions contact or nearly contact each other. If then the screw 8 be screwed on the ring part 9 is clamped firmly on the left hand pipe, but the clamping action of the ring part 10 on the right hand pipe is so slight that relative rotation of the coupling member 7 and the left hand pipe clamped tightly thereon about the longitudinal axis of the right hand pipe remains easily possible. The variant of the coupling member according to Fig. 3 consists in that the endless coupling member 13 made in one piece has two equal ring parts 14,15 which in unloaded condition are too wide and are interconnected by connecting parts 16,17. However, in this case the clamping screw 8 approaches the left hand ring part 14 as much as possible, in such a manner, that when said screw is screwed on, the left hand ring part 14 is clamped on the left hand pipe portion with considerably greater force than the right hand ring part 15 is clamped on the right hand pipe portion. If the diameter of the ring parts and those of the pipes and also the lengths of the connecting parts 16,17 and the resilience of the strip material of the coupling member be well chosen, also in this case the effect occurs that the left hand pipe will be firmly embraced by the coupling member 13, whereas rotation between said member and the right hand pipe remains possible. It is observed that the length of the connecting parts is defined by the required horizontal distance between the upper portions of the pipes forming together the screen. Consequently, it is possible, that the connecting parts become so short that lateral displacement of the clamping screw 8 has hardly any effect. In that case the coupling member according to Fig. 2 must be used.

Claims: A screen adapted to be placed in front of a hearth fire or other source of radiant heat, said screen comprising a row of interconnected, at least for a part of their length horizontally spaced apart round pipes (1,2,3,4) which extend vertically, are placed side by side and have each at or near their lower end an opening (5) to admit air from and at or near their upper end an opening (6) to discharge air into the room to be heated by said source of heat, the two pipes (1,2;2,3;3,4) of at least one pair of adjacent pipes of said screen being so interconnected by a hinge joint, as to ensure that one pipe (1;2;3) of said pair is adapted to swing with its longitudinal axis in a circular cylinder surface about the longitudinal axis of the other pipe (2;3;4) of said pair, said hinge joint consisting of a coupling member (7;13) in one piece of material including two end portion (9,10;14,15), of which each one embraces an individual pipe (1,2;2,3;3,4) of said pair, an intermediate portion (11,12;16,17) interconnecting said end portions and a connecting means (8) so acting on the connection between said end portions of the coupling member (7;13) and the pipes (1,2;2,3;3,4) extending therethrough as to guarantee that in the active end condition said connecting means one end portion (9,14) of the coupling member (7;13) is firmly connected to one pipe (1;2;3), but the other end portion (10;15) embraces the other pipe (2;3;4) in a manner as to allow still a relative rotation of said end portion (10;15) and said other pipe (2;3;4), characterized in that said coupling member (7;13) in one piece of material so includes two end portions, each of which is in the shape of a splitted ring (9,10;14,15) and embraces the pipe (1,2;2,3;3,4) in question of said pair through an angle of more than 180° but less than 360°, and a connecting means consisting of two connecting parts (11,12;16.17) interconnecting in pairs the ends facing each other of said splitted rings, as to form together an endless closed loop, and further in that the connecting means is a clamping means (8) adapted to force said connecting parts (11,12;16,17) one towards the other. A screen according to claim 1, characterized in that in the condition of the splitted ring parts (9,10) of the coupling member (7), when being unloaded by the clamping means (8), the inner diameters of said ring parts are slightly different and the clamping means (8) engages the connecting parts (11,12) of said member (7) midway between the ringparts (9,10). A screen according to claim 1, characterized in that in the condition of the splitted ring parts (14,15) of the coupling member (13), when being unloaded by the clamping means (8), the inner diameters of said ringparts are equal and the clamping means (8) engages the connecting parts (16,17) of said member (13) nearer to one (14) than to the other ring part (15) of said member (13). A method for the manufacture of a coupling member of material in the shape of a closed strip meant for a screen according to claim 2 or 3, characterized in that in the first place a tube with suitable wall thickness and a cross-section in the shape of the required endless closed loop of the coupling member (7,13), when in its unloaded condition, is formed and thereafter, in the next or the opposite order of succession, holes for at least one clamping bolt or screw (8) per coupling member (7,13) are made in the portions of said tube meant for the connecting parts (11,12;16,17) and thereupon pieces, of which the width corresponds with the height of the loop of the coupling member (7,13), are cut from said tube.

Inventors: RATELBAND, JOHANNES BERNADUS
Applicants: RATELBAND, JOHANNES BERNADUS
Application year: 1990
Main classification: F24B1
IPC codes: F24C15, F24B1