US3895512A

US3895512A - Multiple-part machine frame for presses, rolling mills or the like

Info

Publication number: US3895512A
Application number: US368687*[A
Authority: US
Inventors: Ernest Theodor Sack
Original assignee: Maschinenfabrik Sack GmbH
Current assignee: Maschinenfabrik Sack GmbH
Priority date: 1973-10-24
Filing date: 1973-10-24
Publication date: 1975-07-22
Anticipated expiration: 1992-07-22

Abstract

A multiple-part machine frame with a substantially rectangular opening and intended particularly for presses or rolling mills as a pair of longitudinal frame members which are interconnected by transverse frame members through which pass first tie-rods for securing the longitudinal and transverse members. Co-operating force transmitting surfaces are provided on the transverse and longitudinal frame members for transmitting the working force from the transverse frame members to the longitudinal frame members thereby placing the latter under tension. At each corner of the frame are arranged pre-stressed second tie-rods extending through the force transmitting surfaces to interconnect the transverse and longitudinal frame members thus preventing separation of these surfaces when a relieving force acts in a direction opposite to the working force.

Description

United States Patent [191 Sack [ July 22, 1975 1 MULTIPLE-PART MACHINE FRAME FOR PRESSES, ROLLING MILLS OR THE LIKE [75] Inventor: Ernest Theodor Sack, Hosel,

Germany [73] Assignee: Maschinenfabrik Sack GmbH,

Dusseldorf-Rath, Germany [22] Filed: Oct. 24, 1973 [21] Appl. No.: 368,687

Primary ExaminerGranvl1le Y. Custer, Jr. Assistant Examiner-Neil Abrams Attorney, Agent, or Firm-John J. Dennemeyer 57] ABSTRACT A multiple-part machine frame with a substantially rectangular opening and intended particularly for presses or rolling mills as a pair of longitudinal frame members which are interconnected by transverse frame members through which pass first tie-rods for securing the longitudinal and transverse members. Cooperating force transmitting surfaces are provided on the transverse and longitudinal frame members for transmitting the working force from the transverse frame members to the longitudinal frame members thereby placing the latter under tension. At each corner of the frame are arranged pre-stressed second tierods extending through the force transmitting surfaces to interconnect the transverse and longitudinal frame members thus preventing separation of these surfaces when a relieving force acts in a direction opposite to the working force.

3 Claims, 1 Drawing Figure BACKGROUND .OF THE INVENTION 1. Fieldof the Invention The invention relates to multiple-part machine frame with a'substanti'ally rectangular opening as used in forging pressesfirolling mills or ,the'like.

2. Description of the-'Prior Art Machine frames of this type ctin sist of two longitudinal struts subjectto traction and twotransverse struts which are'conne'ctedto the former=atthcir lateral faces by first tie rods'ext'ending at right angles to the longitudinal 'str utsand are-provided at their front endswith projections which transmit the working force by means of inwardly directed projections of the longitudinal struts to the latter. A multiple-part machine frame of this type is described in the German Pat. No. 696,039. This design has several advantages over other designs which it seemed appropriate to develop further. Firstly, in contrast to the conventional construction which is cast in one piece, the fact that the machine frame consists of several parts has the advantage of being easier to manufacture and problems of transportation recede into the background. The longitudinal struts can be cut from rolled steel slabs, which represents an advantage as regards price compared with known constructions of machine frames, whose longitudinal struts are formed by tie-rods or are traversed by pre-stressed tie-rods.

On the other hand, however, there exists a particular problem which the special multiple-part construction according to the above German patent has not effectively solved in practice. This problem relates to the socalled relieving impact which occurs, for example, when the rolled material leaves the rollers of the rolling station, or during forging. Due to these relieving impacts, the force-transmitting surfaces of the lateral projections of both the transverse struts and longitudinal struts which bear against each other in pairs are stressed such that they are rapidly destroyed. For each relieving impact, the force-transmitting surfaces are worked as if by hammer blows.

SUMMARY OF THE INVENTION It is the object of the invention to remove this drawback. This is achieved in that the transverse struts are connected to the longitudinal struts by pre-stressed second tie-rods which pass through the force-transmitting surfaces bearing against each other in pairs and formed by the projections, whereby the pre-stressing safety margin of the tie-rods is chosen so great that under the so-called relieving impact, occurring for example as rolled material leaves the rolls and relief inertia forces on transverse struts and tie-rods are produced, this safety margin is not exceeded. These tie-rods thus eliminate the possibility that at the time of the relieving impact, the force-transmitting surfaces move apart and strike against each other, since the pre-stressing pressure is so great that the inertia forces occurring at the time of the relieving impact lead, in the most extreme case only to a neutralization of the pressure at the force-transmitting surfaces, without the system ever becoming unstressed, i.e. the clamped surfaces moving apart.

Since the force-transmitting surfaces between the transverse struts and the longitudinal struts should have as small a dimension as possible in the transverse direction of the longitudinal strutsain order to transmit the workingforces to the-longitudinal struts with as small a lever arm aspossible, it is advisable that the second tie-rods extend obliquely with respect to the frame parts."

fjBR EF nEscR1PTioN OF THE DRAWING A preferred embodiment of a multiple-part machine frame accroding to the invention is illustrated in the sole FIGURE of the drawing.'-

5 DESCRIPTION 0F THE PREFERRED EMBODIMENT The working force indicated'by the arrows P is firstly taken-up by the transverse struts l and 2 then transmitted to the

longitudinal struts

7 and 8 by

forcetransmitting surfaces

3, 4, 5 and 6. These forcetransmitting surfaces are formed by projections la and 2a, on the front ends of the transverse struts l and 2, on the one hand, and by the inwardly extending, overhanging

projections

7a and 8a of the

longitudinal struts

7 and 8, on the other hand.

In place of a key-and groove engagement between the transverse struts and longitudinal struts, the invention solely provides force-transmitting surfaces 3-6 which transmit the working force P to the

longitudinal struts

7 and 8, which are thereby subjected to tensile stress. The transverse and longitudinal struts are connected to a rectangular frame by means of first tie-

rods

9, 9a and 10, 10a extending transversely to the longitudinal struts.

In order to prevent the force-transmitting

surfaces

3, 4, 5, and 6 from hammering against each other, when relieving impacts occur, the invention provides prestressed tie-rods ll, 12, 13 and 14, extending obliquely through the force-transmitting surfaces. The prestressing safety margin is chosen so high that the inertia forces of the relieving impacts, which can be determined by calculation and which act in opposite direction to the working force P, under no circumstances nullify the clamping effect in the region of the four tierods. The result is that the force-transmitting surfaces remain always in abutment and cannot be destroyed.

What is claimed is:

l. A composite machine frame for highly stressed power presses, rolling mills, and like applications, in which large working forces act to longitudinally deform and stretch the frame, and deformation-related impact relief forces, created by the abrupt cessation of said working forces, act to contract the frame, the machine frame comprising:

a pair of laterally spaced longitudinal frame members extending over substantially the entire length of the frame;

a pair of vertically spaced transverse frame members extending between the upper and lower extremities of the longitudinal frame members so as to constitute mating interfaces therebetween and to circumscribe a substantially rectangular frame opening;

first tie-rods extending lengthwise through the transverse frame members and perpendicularly through said longitudinal frame members for the creation of a transverse clamping force across the interfaces of these members;

a pair of oppositely oriented mating projections in each of the four interfaces between the longitudinal and transverse frame members; each pair of the longitudinal frame members and the transverse frame members of such a magnitude that the clamping pressures are at all times higher than the impact relief forces which tend to separate these members along said force-transmitting surfaces. 2. A machine frame as defined in claim 1, wherein the axes of the second tie-rods inclined at an angle in relation to the orientation of the longitudinal frame members in such a way that they would converge. if extended inwardly. 3. A machine frame as defined in claim 2. wherein the force-transmitting surfaces on the projections of the longitudinal and transverse frame members are oriented in parallel alignment with each other.

Claims

1. A composite machine frame for highly stressed power presses, rolling mills, and like applications, in which large working forces act to longitudinally deform and stretch the frame, and deformation-related impact relief forces, created by the abrupt cessation of said working forces, act to contract the frame, the machine frame comprising: a pair of laterally spaced longitudinal frame members extending over substantially the entire length of the frame; a pair of vertically spaced transverse frame members extending between the upper and lower extremities of the longitudinal frame members so as to constitute mating interfaces therebetween and to circumscribe a substantially rectangular frame opening; first tie-rods extending lengthwise through the transverse frame members and perpendicularly through said longitudinal frame members for the creation of a transverse clamping force across the interfaces of these members; a pair of oppositely oriented mating projections in each of the four interfaces between the longitudinal and transverse frame members; each pair of projections comprising a laterally outwardly extending projection of the transverse frame member, an inwardly Extending overhanging projection of the longitudinal frame member, and intermediate, transversely oriented force-transmitting surfaces by which said projections engage each other for the transmission of the working forces from the transverse frame member to the longitudinal frame member; and second tie-rods extending generally longitudinally through said pairs of mating projections along an axis which intersects their force-transmitting surfaces, said tie-rods being prestressed to such an extent that they maintain longitudinal clamping pressures on the force-transmitting surfaces between the longitudinal frame members and the transverse frame members of such a magnitude that the clamping pressures are at all times higher than the impact relief forces which tend to separate these members along said force-transmitting surfaces.

2. A machine frame as defined in claim 1, wherein the axes of the second tie-rods inclined at an angle in relation to the orientation of the longitudinal frame members in such a way that they would converge, if extended inwardly.

3. A machine frame as defined in claim 2, wherein the force-transmitting surfaces on the projections of the longitudinal and transverse frame members are oriented in parallel alignment with each other.