FI89159C - Horizontal oven for glass plates and where used coupling between the support rollers a and the drive shafts located outside the oven - Google Patents

Description

! 89159

Horizontal furnace for glass sheets and the connection of the support rollers used to the drive shafts outside the furnace

The present invention relates to a horizontal furnace for heating glass sheets and for treating sheets heated to tempering and / or conveying temperature, and in particular to the connection of support rollers to drive shafts located outside the furnace.

15

Numerous embodiments of a horizontal furnace are known in the art, which generally differ in terms of roller coupling and drive devices and roller bearings. Conventional embodiments are disclosed, for example, in EP 51 539, EP 70 244, DE 2 319 049, DE 2 605 303, US 4 230 475, US 4 399 598 and US 4 725 300.

In the hot zone of such horizontal furnaces, the support rollers or cylinders forming the conveyor track usually consist of .25 cylindrical ceramic tubes or rods, the end portions of which are passed through the side walls of the furnace outside the furnace and are mounted on bearings fitted outside the furnace. Bearing of the support rollers to the bearings arranged inside the furnace is not possible by known means .30 due to temperatures in the furnace above 600 ° C.

The support rollers are connected to the drive outside the oven in a suitable manner and are operated synchronously.

35 different implementations are known for bearing support rollers outside the furnace. According to U.S. Patent No. 4,399,598, metal plugs are pressed into each end of the ceramic tubes and each supports a shaft end. These shaft ends are bearing-mounted on conventional ball bearings. According to EP patent publication 2 89159 sun 51 539, each of the end portions of the support rollers is mounted outside the furnace to rotate freely on two horizontally arranged steel rollers.

In addition, according to DE 2 319 049 and DE 2 605 303, the end zones of the support rollers located outside the furnace are arranged on synchronously pulled belts, which in turn slide on flat support surfaces. In the direction of movement of the belts, behind the support rollers, stops or counter rollers are arranged, against which the support rollers rotate and by means of which the support rollers maintain their position during their rotational movement. The use of the support rollers takes place by static friction, which arises from the effect of the weight of the rollers between the moving belts and the support-15 tint rollers placed on these belts.

In order to preserve the optical properties of the glass sheets, the support lines of the rollers must have the smallest possible deviation in the zone of the oven where the glass sheets reach or exceed their softening temperature Λ0. This means that the support rollers must have the smallest possible diameter; in practice, closely spaced support rollers with a diameter of 4-5 cm are used.

25 As the width of the oven increases, which is necessary for heating or processing larger glass sheets, it becomes more difficult to maintain the desired high optical quality of the glass panes. This is because as their length increases while the diameter remains the same, there is an increasing elastic bending in the support rollers due to their own weight and possibly permanent deformations. As a result, the upper straight lines of the support rollers are no longer optimally located in the same and only plane, and this more or less uneven support of the glass sheets 35 leads to a noticeable deterioration in the flatness of the glass panes and a change in their optical properties.

li 3 89159

Although a stretching plant in which roller bearings are arranged inside a furnace is known from DE patent 615 421, this type of furnace has a substantially lower temperature than a convex-tempering furnace. By known means, it is not possible to eliminate the above-mentioned disadvantages by placing the bearings of the support rollers in the heating space.

The invention relates to a horizontal oven for heating glass sheets, in which the connection of the support rollers to the drive device is carried out in such a way as to enable both the appropriate use of the rollers and to reduce heat losses at the connection.

According to a preferred feature of the invention, the coupling of each roll to the drive shaft outside the furnace is performed by a coupling arm which passes through a furnace wall smaller than the roll and articulated to both the drive shaft and the support roll.

The invention is preferably implemented according to the parent application no. In a horizontal oven according to FI-884531 (patent no. 86408).

Furnace costs are significantly reduced due to the shortening of the rolls, as they are usually made of expensive raw materials.

In addition, openings in the oven wall for the use of rollers are minimized; thus the heat losses are very small and a homogeneous temperature profile in the furnace is obtained.

..30

The horizontal furnace, which is a combination of this feature and the features of the basic application, optimally meets the requirements for high optical quality of glass sheets and, in addition, enables industrial mass production.

Other details and preferred features of the invention are set forth below with reference to the accompanying figures, in which Figure 1 is a perspective view of a continuous glass sheet furnace equipped with a switching device according to the invention; Fig. 2 is a perspective view of the switching device; Fig. 3 shows the device of Fig. 2 at the time of disconnection 5; Fig. 4 shows a detail of the coupling piece according to Figs. 2 and 3.

Fig. 1 is a fragmentary view of a horizontal furnace 50 comprising a switching device according to an embodiment of the invention. The transverse oven 50 consists of an upper part 51 and a lower part 52. The upper part 51 can be raised along the separating plane 53. With the furnace closed, the side wall 54 has no opening, while the opposite wall 55 has support rollers 56 at a distance and openings 57 at a height of the plane 53 through which the connecting arms 58 pass through the wall 55.

Inside the furnace, bearings 1 of the high temperature type gas bearings are arranged. The second bearings 1 of the sleeve form 20 support a rectangular tube 2 arranged along the length of the furnace parallel to the side walls 54, 55. The rectangular pipe 2 supplies compressed air to the bearings 1. To this end, it receives compressed air through the supply pipe 40. Compressed air exits through openings 5 made in the sliding surface of the bearing 1 to form a gas film.

The support rollers 56 are of a heat-resistant material, for example a ceramic material, and may be solid or hollow.

As shown in detail in Figures 2-4, the coupling arms 58 are articulated to the rollers 56 on the one hand and to the drive shaft 60 on the other side outside the furnace. the segment 63 has a drive spindle 64 oriented perpendicularly

II

5 89159 to the shaft of the arm 58 and interleaved into the slot 65 oriented along the radial of the roll.

The spherical segment 63 comprises two cylindrical segments 66 arranged symmetrically so that the base lines of these segments are parallel to the axis of the mandrel 64. The radius of the cylinder forming the segments 66 corresponds to or is possibly slightly smaller than the radius of the bore 68 oriented along the axis of the roll 56.

10

Shaft 58 of the roller 56 to release arm 58 must rotate 90 ° in the direction of the arrow F (Figure 2) the switching arm 58 and the spindle 65 formed by the plane. In this position, the base lines of the cylindrical segments 66 are parallel to the axis of the roll 56 and the spherical segment 63 can be removed through the bore 68.

To secure or remove the arm 58 from the roll 56, the oven top 51 must first be lifted and the other end of the arm 58 20 removed from the drive shaft.

The connection of the arm 58 to the drive shaft 60 is made by a coupling piece 70 at the end of the drive shaft 60. The coupling piece 70 comprises a spherical housing-shaped recess 71, 25 in which a cylindrical segment 72 is fitted at the drive end 58 of the coupling arm 58. it appears that the spherical housing 71 is located in the half-cylinder 74 at the end of the coupling piece 70 so that the arm 58..30 can be removed by twisting from the coupling piece 70 with the cylindrical segment 2 in the position shown here. A slider 75 in the form of a recess is movably mounted at the end of the shaft 60. As a result of the spring 76, the slider 75 protrudes to its extreme position as in Fig. 3, in which the cylindrical segment 72 engages the housing 71. The jacket 77 attached to the slider 75

6 89159

The bearing 1 of the roller 56, which supports the tube 2, is in accordance with the base application.

Such a horizontal furnace is in particular intended for heating the glass sheets 5 in order to shape and / or temper them specifically for the manufacture of car windscreens.

li

Claims (5)

7 89159 A horizontal furnace for heating glass sheets, in particular for conveying and / or tempering them, comprising synchronously driven support rollers (56), characterized in that the support roll (56) is connected to a drive shaft (60) outside the oven by a connecting arm (58) passing through the side wall of the oven. (55) and having a smaller diameter than the support roller (56), the coupling arm being articulated to both the drive shaft (60) and the support roller (56). A horizontal oven according to claim 1, characterized in that at each end of the coupling arm (58) there are cylindrical segments (63, 72) arranged in spherical housings (62, 71) corresponding to a support roller (56) and a drive shaft (60). ) and that the drive spindles (64, 73) function to receive the rotational movement. A horizontal furnace according to claim 1 or 2, characterized in that the cylindrical segment (63) acting on the support roll (56) with the spherical housing (62) comprises two segments (66) whose base lines are parallel to the drive spindle axis (64). ), the diameter of the cylinder forming the segments being less than or equal to the diameter of the bore (68) at the front end of the support roll (56). Horizontal oven according to one of Claims 1 to 3, characterized in that the spherical housing (71) cooperating with the cylindrical segment (72) is arranged in a half-cylinder (74) at the end of the coupling piece: and in a movably mounted manner. a hollow cylindrical slider (75) that secures the cylindrical segment (72) to the housing (71) and remains in place by the spring (76). Horizontal oven according to one of Claims 1 to 4, characterized in that the support rollers (56) are ceramic. 8 89159