Bendable support structure in a bending section

The invention relates to a bendable or vaulting support structure in a bending section or bending and tempering section for glass sheets or panels. The support structure comprises a plurality of support arms (10), which are attached by pivotal joints (7) to each other for a vaulting bridge. Each support arm (10) includes a bracket member (6) protruding from between two pivotal joints (7). Between the bracket members (6) is provided a guide lever mechanism, which directs bending or vaulting of the support structure with a constant-radius curvature. The guide lever mechanism is established by levers (11, 12, 13) set in a Z-pattern and provided with five pivotal joints (1-5), three (1, 4, 5) of which engage with the bracket members (6), and two articulated axles (2, 3) present therebetween, which connect the lever arms (11, 12, 13) to each other, are capable of moving relative to the bracket members (6).

The invention relates to a bendable support structure in a bending section or bending and tempering section of glass sheets or panels, said support structure comprising1) a plurality of support arms, which are attached by pivotal joints to each other for a curving bridge, each support arm including a bracket member protruding from between two pivotal joints, and2) a guide lever mechanism established by levers articulated between the bracket members of the support arms, which directs vaulting or bending of the support structure with a constant-radius curvature.

This type of support structure is known from the Applicant's patent publications U.S. Pat. No. 5,881,962 and U.S. Pat. No. 5,057,137. In this prior known solution, the equal-radius vaulting or curvature is established hydraulically by means of serial cylinders. Patent publication U.S. Pat. No. 5,498,275 discloses a support structure the uniform curvature or vaulting of which is established by means of control lever mechanism, having its articulated axles between the levers perpendicular to the glass to be bent.

It is an object of the invention to provide a bendable or vaulting support structure, wherein a constant radius of curvature can be ensured by a comparatively simple guide lever mechanism, with the directions of levers making it possible to have minor leverage forces and, thus, a lightweight support structure. Consequently, the inventive support structure can be applied in longer-than-before bridge structures without creating excessive weight-related stresses.

This object of the invention is achieved on the basis of the characterizing features set forth in the appended claim1.

The non-independent claims disclose preferred embodiments of the invention.

The vaulting bridge formed by the support structure can be trussed at its ends and supported at one or more points between its ends by a mechanical or hydraulic hoisting mechanism capable of lifting the bridge to a rectilinear condition or sagging to a curvature. Alternatively, the bridge may be fixed in vertical direction at its mid-point, in which case both of its ends are lifted and lowered. A third alternative is that one end of the bridge is vertically fixed and non-pivotable, whereby the other end of the bridge can be lifted and lowered for vaulting or rectifying the bridge. The support structure is used for bearing a roll conveyor and jet box beams present in a bending section or bending and tempering section, in such a way that the array of conveyor and box beams is caused to bend in a manner complementary to the support structure to a constant-radius curvature. Whenever the support structure is used in a simple bending section without tempering, the section is nevertheless provided with small jet boxes for heat strengthening the bent glass panels.

The support structure comprises a plurality of support arms10, which are attached by pivotal joints7to each other for a vaulting bridge. Each support arm10includes a bracket member6protruding from between two pivotal joints7and having its center axis9perpendicular to a connecting line8between the pivotal joints7and crossing the connecting line8at an equal distance from the pivotal joints. The bracket member6comprises two spaced-apart plates6a, between which is located a guide lever mechanism, comprising levers12,13which connect adjacent bracket members6to each other. This guide lever mechanism, established by lever arms11,12,13articulated between the bracket members6, directs the support structure to sag with a constant-radius curvature. In order to make this possible, the guide lever mechanism associated with each bracket member includes levers and joints as follows:a) a first guide lever or wheel11, which is pivotably bearing-mounted to the bracket member6by means of a first articulated axle1and which is provided with second and third articulated axles2,3placed on the opposite sides of the first articulated axle1;b) a second guide lever12, which extends between said second articulated axle2and a fourth articulated axle4attaching to the first adjacent support arm; andc) a third guide lever13, which extends between said third articulated axle3and a fifth articulated axle5attaching to the second adjacent support arm6.

All articulated axles1-5of the guide lever mechanism have an axial direction which is the same as that of joints7between the support arms10. The second and third articulated axles2,3are located at unequal distances from the first articulated axle1, the greater distance being closer to the distal end of the bracket member6. The difference in distances is roughly equal to the difference in motion ranges between the second and third articulated axles2and3, which results from the fact that the guide levers12and13are located at unequal distances from the pivotal joints7. In other words, the relationship between distances of the levers12,13from the pivotal joint7is the same as the relationship between lever arms of the lever11on the opposite sides of the articulated axle1.

The articulated axle1is located on a line9coincident with the bisector of a connecting line8between two pivotal joints7and perpendicular to this connecting line8.

When the bridge is in its extended rectilinear condition, the articulated axles2and3are located on the opposite sides of the line9, which extends through the articulated axle1and is perpendicular to the arch of the bridge. As the bridge is vaulted or bent, the articulated axles2and3move across the line9.

The second and third guide levers12,13of the guide lever mechanism are substantially parallel to each other and define an acute angle with the first guide lever11when the bridge is in its extended rectilinear condition. However, the acute angle between the levers progresses through a right angle to an obtuse angle as the bridge is in the process of vaulting or bending. In the present context, directions of the levers11,12,13are conceived as the directions of connecting lines between the articulated axles2-5present at the ends thereof.

As depicted inFIG. 3, the first guide lever11is constituted by two parallel levers11a, between whose ends are located the ends of the second and third guide levers12,13. The levers12,13are subjected mainly to a tensile stress. The levers11are subjected to an almost perpendicular bending stress over relatively short lever arms. The guide lever mechanism does not require any extra space in lateral direction unlike e.g. the solution disclosed in Patent publication U.S. Pat. No. 5,498,275.

The bridge constructed with a support structure of the invention may have a length of more than 4 m, and hence capable of bending very large glass sheets or panels.