US3239618A

US3239618A - Apparatus for guiding strip stock

Info

Publication number: US3239618A
Application number: US254616A
Authority: US
Inventors: Kurt E Sengel
Original assignee: DRIAM SA
Current assignee: DRIAM SA
Priority date: 1962-02-02
Filing date: 1963-01-29
Publication date: 1966-03-08
Anticipated expiration: 1983-03-08
Also published as: GB960566A; DE1208145B

Description

March 8, 1966 K. E. SENGEL 3,239,613

APPARATUS FOR GUIDING STRIP STOCK Filed Jan. 29, 1965 K J M 25/ 9 a 10/ l M Z 4 O L/ 1a 7 73 lNVENToR KURT E. SENGEL RTTORNEYS United States Patent 3,239,618 APPARATUS FOR GUIDING STRIP STOCK Kurt E. Sengel, Friedrichshafen, Germany, assignor to Driam Socit Anonyme, Vaduz, Liechtenstein Filed Jan. 29, 1963, Ser. No. 254,616 Claims priority, application Germany, Feb. 2, 1962,

38,073 7 Claims. (Cl. ZOO-61.18)

The present invention relates to an apparatus for guiding strip stock and the like. 1

In numerous processes in which sheet materials in the form of strips, bands, or sheets have to be fed and accurately guided in their longitudinal direction so that either their central axes or one of their edges will remain in their prescribed positions, considerable difficulties occur when the strip band or sheet varies in width which happens very frequently as the result of inaccuracies in manufacture. Although these difficulties may be reduced to some extent by a special edge trimming operation, often it is even then difficult to avoid them completely unless a considerable amount of material is cut off which is thus wasted entirely.

When speaking hereafter only of strips this term is intended to include generally any sheet material in the form of strips, bands, sheets, or the like.

The apparatus for guiding such strips generally consist of rollers or sliding jaws which are usually adjustable in a direction transverse to the axis of the strip in accordance with the nominal width of the strip by means of screw spindles or the like. It is a well-known fact that, if the strip which is being fed varies in width, there is either considerable play between these guiding means and the edges of the strip or the guiding means will exe'r't too great a pressure upon these edges.

Since both of these occurrences should be avoided as much as possible, the guiding means for one or both edges of the strip are usually resiliently mounted. The result is then either a varying pressure upon the edges of the strip, for example, if the guiding means are acted upon by springs, or a constant pressure, for example, if

the guiding means are acted upon by hydraulic or pneumatic cylinders. This pressure upon the edges of the strip may also be adjusted in accordance with the dimensions and the type of material of the strip.

All of these resilient guiding means have the disadvantage that the pressure upon the edges of the strip :must be exerted continuously since, if they operate, for example, with springs of an insufiicient strength and the strip decreases in width, they are no longer able to shift the strip laterally and thus fail to carry out their guiding function.

The known guiding means therefore do not permit untrimmed strips which have the usual manufacturing tolerances amounting, for example, to approximately 1% of the nominal width of the strip, to be guided in such a manner that there will always be a constant light guiding pressure upon the edges of the strip and that a sufiicient force will also be exerted upon the strip so that, if it should tend to run in a slightly oblique direction, it will be maintained in or returned to the desired position.

It is an object of the present invention to provide suitable guiding means which exert a relatively :low pressure upon the edges of the strip as long as the strip is of a normal condition, that is, as long as the width of the strip remains the same and also as long as these guiding means are in engagement with both edges of the strip. If, however, only one or both edges of the strip disengage from the guiding means or if the pressure of the latter upon one or both edges of the strip increases beyond a preset limit, the invention provides that the guiding means are moved automatically in one or the other direction in such a manner that the pressures which are exerted upon the edges of the strip will remain within certain adjustable limits so that any damage to the edges of the strip or to the guiding means'will be prevented.

According to the invention, this object is attained by providing one or more pairs of guiding means which are movable perpendicularly to the axis of the strip and wherein those of each pair are disposed directly opposite to each other at both edges of the strip. These guiding means possess the following features:

(1) Each of these guiding means comprises a guiding element and a supporting slide member therefor which is capable of reciprocating within a normally stationary slide carriage or housing for a relatively short distance between two fixed stops in a direction transverse to the edges of the strip, and this distance is adjustable, although it is always considerably smaller than the tolerances in the width of the strip which are normally to be expected.

(2) Each guiding element is pressed against the edge of the strip or against the respective stop by a relatively weak spring which only needs to be strong enough to compensate for the friction caused by this guide element and the other elements within each carriage.

(3) In addition to this weak spring, preferably a coil spring, a hard spring, for example, a cup spring, is provided in such a manner that the distance of travel of both springs together is divided into a longer part with a practically constant but relatively weak spring pressure of the coil spring and a smaller part with a strongly increasing spring pressure of the cup spring.

(4) The normally stationary carriages for each pair of guiding elements are adjustable relative to each other, for example, by an electric motor and a screw spindle with right and left-hand threads, and such an adjustment may be carried out manually by the operation of a pushbutton for the purpose of adjusting the guiding elements to the normal width of the strip and also automatically by means of a limit switch with which each slide carriage is equipped and which is actuated by the stroke of the guide element. Each limit switch has, for example, three switching positions so that both limit switches together are capable of attaining nine possible switching combinations for controlling the electric motor. Two of these nine combinations are employed for starting the motor in its two different directions of rotation, while all of the other seven switching positions will either cause the motor to stop or not permit it to start.

(5 The limit switch which is installed in each carriage is adapted to be adjusted in such a manner that the stroke of this switch which is smaller than the stroke of the guiding element may be carried out at any desired location within the distance of the stroke of the guiding element and that, if desired, it may also be adjusted so as to change the length of its stroke.

The present invention therefore consists in the application of these five features and their combination and association with each other, whereby all of the requirements for properly guiding a metal strip will be accomplished so that, for example, the strip may be guided along one edge, for which purpose it is merely necessary to adjust the carriage on the side opposite to this edge, or the strip may be guided so that its central axis always remains in a constant position by carrying out an adjustment of both carriages in opposite directions symmetrically to the central axis of the strip, while the pressure upon the edges of the strip may be manually adjusted as desired at any time during the guiding operation.

Another feature of the invention consists in the possibility of connecting auxiliary devices in a very simple manner to the adjusting means for the carriage for indicating or registering at any time or continuously the Width of the metal strip or for giving a signal whenever the strip exceeds or is narrower than a certain desired Width.

The various features and advantages of the present invention will become more clearly apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings of which;

FIGURE 1 shows a longitudinal section of one of a pair of associated slide carriages while,

FIGURE 2 shows the aforesaid pair of carriages and their associated relationship.

In the drawings, each guide element 1 is illustrated in this particular embodiment of the invention as consisting of a roller which is rotatably mounted in a bifurcated slide member 7 and adapted to engage upon one of the edges of the strip 8 which is to be guided. Slide member 7 is slidably guided in a socket of a housing or carriage 2. A coil spring 3 and a cup spring 4 are mounted within this socket so that the slide member 7 will be pressed with a relatively Weak pressure in the direction of the arrow 19. As more particularly shown in FIGURE I slide member 7 is capable of carrying out a stroke H, the end positions of which are determined by the cup spring 4 when in the flattened condition and the front end of a bushing 11 which is threaded in the bottom of the socket and mounted on the shaftlike extension of slide member 7 so as to be rotatable and axially slideable thereon. Bushing 11 is adjustable to different positions in its axial direction relative to carriage 1 and from the outside thereof by means of a shaft 9 with a square outer end and a pinion 10 on its inner end which engages with a set of gear teeth on the threaded bushing 11. When shaft 9 is turned in one or the other direction, bushing 11 is screwed either toward or away from cup spring 4, whereby the length of the stroke H of slide member 7 may be regulated. As shown, a nut for a selective abutment by bushing 11 is disposed on the shaft-like extension of slide member 7 in normally spaced relationship from the bushing to afford a variable clearance I-I-x. The rear end of the shaftlike extension of slide member 7 carries a pin 12 which acts upon a contact arm 13 of a limit switch 5 provided with leads 18. The particular position where the limit switch 5 may carry out its stroke may be varied by means of a setscrew 14. The two carriages 2 which are associated with each other and may form one of several pairs are connected with each other by means of a spindle 15 with right and left-hand threads which is adapted to be driven in either direction by an electric motor 6 through a reduction gear 16 so that, by means of a nut 17 which connects each carriage 2 with spindle 15, both carriages may be moved toward each other when the Width of strip 8 decreases or away from each other when the width of the strip increases. The electric circuit of the two limit switches 5 of each pair of associated carriages 2 for operating the motor 6 is not illustrated in the drawings as its design will be obvious to any person familiar with the art.

The end 20 of spindle 15 may be connected to any desired auxiliary devices, for example, to an indicating instrument which may also be provided with a recording device and signal means for measuring and indicating the width of the metal strip. These auxiliary devices are also not illustrated in the drawing since they may be of various designs.

Of course, instead of carrying out the adjusting movements of the two carriages 2 by means of a single motor and a spindle with right and left-hand threads, it is also possible to connect the carriages to two separate spindles which are driven by separate motors. This may be advisable, for example, if a very wide strip is to be guided along its edges. These motors may then run synchronously with each other, and, if desired, it is also possible to operate only one motor to adjust the associated carriage, while the other motor and carriage are standing still.

The advantages which are attained according to the invention by being able to guide a strip or the like very accurately without exerting any undue pressure upon its edges are of very great importance in numerous operations, for example, in edge-trirnming, shaping, pipe weld"- ing, punching, cold-rolling, etc.

Although my invention has been illustrated and described with reference to the preferred embodiment thereof, I wish to have it understood that it is in no way limited to the details of such embodiment, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. An apparatus for guiding a metal strip or the like of a changing width during its movement in its longitudinal direction between a pair of guiding means, each of said guiding means being mounted for longitudinal movement in one of a pair of slide carriages, spring means adapted to press said guiding means against one edge of said strip, means for adjusting the carriages of said pair of carriages relative to each other; mutually facing cooperating means on each of said guiding means and on each respective carriage for limiting the length of the stroke of each guiding means within its slide carriage to a distance considerably smaller than the distances traversed by said guiding means due to the changes in width of the strip as caused by normal manufacturing tolerances, and switch means mounted within each carriage, comprising a movable switch arm, each of said guiding means comprising a shaft having means projecting axially from one end thereof for contacting an end portion of said movable switch arm at one end of said stroke to close said switch means.

2. An apparatus according to claim 1, wherein said means projecting axially from said one end is constituted by a pin member.

3. An apparatus according to claim 1, wherein each of said guiding means comprises abutment means, each of said slide carriages comprising socket means, a spring abutting each of said abutment means and said socket means and yieldingly opposing said longitudinal move ment of said guiding means in the direction of a respective one of said switch means.

4. An apparatus according to claim 3, further comprising means for adjusting the length of said stroke of each of said guiding means, including an abutment member on each of said slide carriages, each of said socket means comprising a threaded bushing member adjustably threaded on a respective one of said carriages, and a spring member interposed between a respective said abutment member and a respective said threaded bushing member.

5. An apparatus according to claim 4, said spring member comprising a cup spring abutting each said abutment member and an end of each said threaded bushing, the tension of each said cup spring being adjusted by adjust ing movement of a respective threaded bushing.

2 5 6 6. An apparatus according to claim 4, further com- References Cited by the Examiner prising means for adjusting each said threaded bushing, UNITED STATES PATENTS 3: 1??? iqmpnslgg f tieth 2,317,468 4/1943 Krieger 33 147 re e us mg an se ec rvey operae pinion mean 5 2,410,718 11/1946 Crawford 200 61 X engagmg Smd gear teeth- 2,552,459 5/1951 Rice 200-61 '7. In an apparatus according to claim 1, each of said 2,301,308 7/1957 cubeuis 200*61 switch means being provided with set screw means for varying the position of said switch means on a respective BERNARD GHHEANY Pnmm'y Exammer' carriage. NEIL C. READ, Examiner.