US3835689A

US3835689A - Device for corrugation of strips

Info

Publication number: US3835689A
Application number: US00252034A
Authority: US
Inventors: I Moroz; M Shitsman; A Badamian; G Margulis; G Antonenko
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-10
Filing date: 1972-05-10
Publication date: 1974-09-17
Anticipated expiration: 1991-09-17

Abstract

Device for corrugating strips, comprising punches linked by a driving camshaft, wherein each punch has means for withdrawing it from a cooperating forming surface at the moment of feed of the strip being corrugated. This means includes an auxiliary cam secured on the driving camshaft and a pusher interacting with said auxiliary cam, and secured on one arm of a lever whose other arm is connected to the punch, said lever being adapted for transmitting reciprocating motions to said punch from said camshaft.

Description

United States Patentv Antonenko et al.

1451 Sept. 17, 1974 DEVICE FOR CORRUGATION OF STRIPS [76] lnventors: Grigory Semenovich Antonenko,

ulitsa Yanvarskogo vosstania, Odessa; Avetik Artashesovich Badamian, ulitsa Goncharova, l7, kv. 51, Moscow; Grigory Borisovich Margulis, ploschad Potemkintsev, 3, kv. 2, Odessa; llya Alexandrovich Moroz, ulitsa Varnenskaya, 9, kv. 26, Odessa; Mikhail Borisovich Shitsman, ulitsa Chicherina, 31, kv. 13, Odessa, all of U.S.S.R.

[22] Filed: May 10, 1972 211 App]. No.2 252,034

52 us. c1. 72/385 [51] Int. Cl 821d 13/02 [58] Field of Search 72/385, 380, 386, 389, 72/412, 474

[56] References Cited UNITED STATES PATENTS 2,489,125 11/1949 Dyson 72/403 3,009,510 1 H1961 Meshulam .7 72/385 3,479,855 11/1969 Ogilvie 72/383 FOREIGN PATENTS OR APPLICATIONS 295.121 4/1965 Netherlands 72 385 4,215 10/1876 Great Britain 1 72/385 79,227 6/1950 Czechoslovakia 72/385 Primary ExarninerCharles W. Lanham Assistant Examiner-Gene P. Crosby Attorney, Agent, or Firm-Waters, Roditi, Schwartz & Nissen 5 7 ABSTRACT Device for corrugating strips, comprising punches linked by a driving camshaft, wherein each punch has means for withdrawing it from a cooperating forming surface at the moment of feed of the strip being corrugated. This means includes an auxiliary cam secured on the driving camshaft and a pusher interacting with said auxiliary cam, and secured on one arm of a lever whose other arm is connected to the punch, said lever being adapted for transmitting reciprocating motions to said punch from said camshaft.

2 Claims, 3 Drawing Figures PATENIEDSEP 1 71014 SHEET 2 [IF 2 IIIII 1 DEVICE FOR CORRUGATION or STRIPS The present invention relates to metal-shaping devices and more particularly it relates to devices for corrugation of strips.

' The present invention can be used most effectively for making fins of finned-tube heat exchangers which require a high accuracy of the corrugations with regard to their height,

Known in the art devices for corrugating strips by punches which are kinematically interconnected by a driving camshaft for alternating-opposite reciprocating strokes in a direction perpendicular to a fixed supporting element of one of the punches, said element being provided with a slot for the passage of the other punch whose supporting element is adapted for a joint movement with the first punch in the direction parallel to the fixed supporting element.

In these known devices the punches are actuated by a single cam which operates one of the punches directly, and the other punch via a pusher. In the known devices there is a clearance between each punch and its supporting element. This clearance is constant and larger than the thickness of the strip being corrugated because this clearance is required not only for feeding the strip into the device but also for the free movement of the movable supporting element with one of the punches parallel to the fixed supporting element.

The provision of a constant clearance between the punches and their supporting elements makes it impossible to produce corrugations of a constant definite height and of a rectangular shape owing to the free movement of the strip around the punches.

A constant height of the corrugations becomes particularly important in the manufacture of the finnedtube heat exchangers. If this requirement is not satisfied, not all corrugations of the strip will be soldered to the primary surface of the heat exchanger, which will impair its thermal conductivity and strength.

The rectangular shape of the corrugations is vital for better strength of the corrugated strip in the finnedtube heat exchangers when working under medium and high pressures.

It is a well-known fact that the contacting surfaces of the moving parts of any device become gradually worn in operation. This impairs the accuracy of production, calls for repairs of the devices and leads to difficulties in their operation.

In the known devices the wear of the contacting surfaces of the cam, punch and pusher results in a gradual reduction of the punch stroke. As a consequence, the clearances between the punches and their supporting elements grow which reduces the height of the strip corrugations.

Besides, wear of the rubbing surfaces of the parts which move one of the punches parallel to the fixed supporting element reduces this movement.

As a result, the punches start chopping the strip.

An object of the present invention resides in eliminating the aforesaid disadvantages.

The main object of the invention is to provide a device for corrugating strips by punches which are moved in such a manner and have such a kinematic linkage with the driving camshaft that the device produces corrugations of an equal height and of a preset shape, and which is convenient in operation and reliable.

arm of a lever rocking on a fixed rockshaft, the other' arm of this lever being connected with the punch and said lever being adapted for transmitting reciprocating motions to said punch from said camshaft.

It is advisable that one arm of the lever is made in the form of a yoke fitting around the driving camshaft and carrying the pusher of the punch-withdrawing means on oneend, and a pusher which is in a constant resilient contact with the drive cam of said camshaft on the other.

The device for the corrugation of strips realized according to the invention produces corrugations of an equal height and of a predetermined shape, is convenient in operation and reliable.

Now the invention will be described in detail by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal section, partly cut-away, of the device for corrugating strips according to the invention;

FIG. 2 is a section taken along line 11-11 in FIG. 1, enlarged; and

FIG. 3a, b, c, d, e, g, i illustrates successive motions of punches in the process of strip corrugation.

The device for corrugation of strips according to the invention comprises punches l and 2 (FIG. I) linked kinematically by a driving camshaft to ensure alternating-opposite reciprocating strokes in the direction of arrow A, perpendicular to a fixed supporting element 3 of one of the punches 1, 2.

The fixed supporting element 3 is secured on a bed 4 and has a slot 5 for the passage of the other punch 2. A supporting element 6 of the punch 2 is adapted for joint movement with the punch 1 along arrow B, parallel to the fixed supporting element 3.

The supporting element 6 is provided with a slot 6a to allow the passage of the punch 1 therethrough.

According to the invention, each punch has means for withdrawing it from its supporting element 3 or 6 at the moment of feeding of a strip 7 to be corrugated.

The punch 1 is withdrawn from its support element 3 by the aid of means comprising an additional cam 9 secured on a drive camshaft 8, and a pusher 10 coacting therewith, which is mounted on one am C of a lever 11 with a stationary rocker shaft 12, while its other arm D is attached to the punch 1.

The lever 11 is intended for imparting to the punch l reciprocating motion from the camshaft 8. In accordance with the invention, the arm C of the lever 11 is in the form of a yoke embracing the drive camshaft 8 and mounting on its one side the pusher 10 of the means to draw off the punch l, and on its other side a pusher 13 which is in constant resilient contact with a drive cam 14 of the shaft 8.

In the described specific exemplary embodiment of the device, the punch l is secured on a slide 15. Another slide 16) will be described somewhat later. The slide 15 mounting the punch 1 is disposed in guides 15a of the carriage 17 which, in turn, is mounted on rams l8 and is able to move in guides 18a in the direction of arrow B, parallel to the movable support element 3, said guides being provided on the bed 4.

These movements of the carriage 17 in the direction of arrow B, together with the slide 15, are effected by the aid of a cam 19 attached to the shaft 8, as a result of alternating coaction of the cam with spring-loaded pushers that are arranged in diametral relation to the cam 19 on a bracket 21 which is attached to the rams 18 by pins 21a.

As shown in FIG. 2, the pusher 13 is a sleeve accommodating a spring 23 which thrusts with its one end against the sleeve bottom, while its other end rests on a bearing 22 (see FIG. 2) which is secured by a screw 24. This screw is intended to control the effort of the spring 23, thus providing a permanent resilient contact between the pusher l3 and the drive cam 14.

Being similar in design to the pusher 13, pushers 20 are provided with a rest shoulder 20a limiting their stroke. Provided inside the pushers 20 are springs 23a whose effort is adjusted by screws 20b.

A slide 16 to carry the punch 2 is mounted in guides 16a of the bed 4.

Mounted on a camshaft 8a are cams 9a and 14a which impart reciprocating motions to the punch 2 via a pusher 10a and a lever 11a, complete with a stationary rocker shaft 12a, which coacts with said earns, the reciprocation being effected in the direction of the arrow A.

Having the same design as the lever 11, the lever 11a comprises an arm Da connected to the punch 2, and an arm Ca which is embodied as a yoke embracing the drive camshaft 8a, and mounts on its one side the pusher 10a of means to withdraw the punch 2 from its support element 6, while attached to its other side is a pusher 13a which is in a permanent resilient contact with the drive cam 14a of the camshaft 8a. The design of the pusher 13a is the same as that of the pusher 13. Provided inside the pusher 13a is a spring 23b whose effort is adjusted by a screw 24b.

In the exemplary embodiment of the device thus described, the camshafts are operatively interconnected via a gear transmission (not shown in the drawing), having a gear ratio of 1:1.

These camshafts mount the drive earns 14, 19 and 14a, as well as the cams 9 and 9a of the means to draw off the punches l, 2 at the moment the strip is being moved, in such a manner as to make the punches perform, in an alternating order, opposite reciprocating motion, and the punch 1 performs longitudinal motions.

A few parts not described so far will be explained hereinafter, together with their operation.

The device according to the invention functions as follows. As shown in FIG. 1, on starting an electric motor 25 the

camshafts

8, 8a are set in rotation via a V-belt drive 26 and a speed reducer (not shown in the drawing).

Having been adapted to draw off the punch 1, the additional cam 9 is mounted on the camshaft 8 such that it is able to actuate the punch 1 via the pusher 10 and the lever 11, thereby forming a clearance between the punch and its support element 3 at the moment when the punch 2 is positioned'at its maximum distance from the support element 6. This clearance is created owing to a compression of the spring 23 of the pusher 13, which is in permanent resilient contact with the cam 14.

At this very moment the strip 7 to be corrugated is fed along guide rollers 27, which are provided on a bracket 28, into the clearance built between the punch 1 and the support element 3. Then the cam 9,is disengaged from its contact with the pusher 10, and the punch 1, owing to the effect of the force of the spring 23, which is transmitted by the lever 11, presses the strip 7 against the support element 3 (FIG. 3a).

As the

camshafts

8, 8a (FIG. 1) are further rotated, the drive cam 14a via the pusher 13a, which is in permanent resilient contact therewith, and the lever 11a move the punch 2 towards its support element 6. At this juncture, the punch 2 presses the strip 7 against the support element 6, whereupon the spring 23b of the pusher 13a is compressed, because the cam 14a is able to move the pusher 13a at a distance which is greater than the total stroke of the punch 2, which is equal to the distance from the support element 6 to the point at which the punch is found at the maximum distance from that element (FIG. 30).

As shown in FIG. 1, the drive cam 14 of the shaft 8, while rotating, then enters in contact with the pusher l0 and moves the punch 1, via the lever l 1, drawing the punch off the support element 3 through the full stroke which is greater than the distance between the elements 3 and 6.

Being adapted to draw off the punch 2, the additional cam via the pusher 10a and the lever 11a actuates the punch 2, thereby forming a clearance between it and its support element 6 and thus disengaging the strip 7 to be corrugated (FIG. 36). This clearance is created owing to the compression of the spring 23b (FIG. 1) of the pusher 13a.

Then the cam 19 coacts with the left-hand pusher 20 and moves the carriage 17, which is mounted on the rams 18, along the guides 18a through a full corrugation pitch to the left until an adjusting nut 29 thrusts against the bed 4. The full corrugation pitch equals the sum of the thicknesses of the punches 1 and 2 and of the double thickness of the strip 7 to be corrugated.

Then the spring 23a of the left pusher 20 is compressed, because the cam 19 moves the pusher 20 through a distance which is greater than the full pitch of a corrugation.

The additional cam 9a is disengaged from its contact with the pusher 10a, and the punch 2, while being acted upon by the force of the spring 23b, which is transmitted by the lever 11a, presses the strip 7 against the support element 6 (FIG. 3d).

On having performed all the motions enumerated above, the punches 1 and 2 complete the formation of the first half of a corrugation.

As the

camshafts

8, 8a are further rotated, the drive cam 14 via the pusher 13, which is in permanent resilient contact therewith, and the lever 11, move the punch 1 towards its support element 3. At this juncture, the punch l presses the strip 7 to the support element 3, and then the spring 23 of the pusher 13 is compressed because the cam is able to move the pusher 13 through a distance which is greater than the full stroke of the punch 1, which equals the distance from the support element 3 to the point wherein the punch is found at its maximum distance from that element (FIG. 3e).

Then the drive cam 14a (FIG. 1) of the shaft 8a,

while rotating, enters in contact with the pusher 10a and moves the punch via the lever 11a, drawing the punch of the support element 6 through a full stroke which is greater than the distance between the elements 3 and 6.

Being adapted to draw off the punch 1, the additional cam via the pusher l and the lever 11 actuates the punch 1, thereby forming a clearance between the punch and its support element 3 and thus disengaging the strip 7 to be corrugated (FIG. 3g). This clearance is created owing to the compression of the spring 23 of the pusher 13.

Then the cam 19 (FIG. 1) coacts with the right pusher 20 and moves the carriage 17 which is mounted on the rams 18in the guides 18a through the full pitch of a corrugation until an adjusting nut thrusts against the bed 4. At this juncture, the punch 1, while moving together with the carriage. 17, moves the corrugated strip 7 through one pitch.

Thereafter, the spring 23a of the right-hand pusher 20 is compressed because the cam 19 moves the pusher 20 through a stroke which is greater than the full pitch of a corrugation.

The additional cam 9 disengages from contact with the pusher l0, and the punch, while being acted upon by the force of the spring 23, presses the corrugated strip 7 against the support element 3 (FIG. 3i).

This completes a full revolution of the

camshafts

8, 8a, and the punches 1, 2, after completing all the movements enumerated above, finish the process of manufacturing a complete corrugation. The formation of a complete corrugation of the strip comes to completion at each subsequent revolution of the

camshafts

8, 8a.

It follows from the above that the strip is corrugated by one of the punches of the device according to the invention at the moment when the strip is pressed by the other punch to its supporting, element, while during the movement of the strip it is released due to clearances formed between the punches and their supporting elements.

Such a design of the device according to the invention makes it possible to corrugate strips with a particularly high accuracy with regard to the height of the corrugations.

The height of the corrugations depends on the distance between the supporting elements. The clearances between the punches and their supporting elements ensure the quality and shape of the corrugations during the movements of the strip.

It is obvious that the device according to the invention can be used for producing corrugations of other than rectangular shapes. For this purpose it is sufficient urations.

The wear of the contacting surfaces of the cams, pushers, and punches in the device according to the invention exerts no influence on the accuracy of corrugations relative to their height and on their shape since the kinematic chain of the device comprises cams which move the pushers through distances larger than required, and resilient elements (springs) which make up for the wear of the contacting surfaces. This guarantees a high reliability of the device, renders its convenient in operation and dispenses with the necessity for frequent adjustments in service.

The device according to the invention can be used most effectively for making fins of finned-tube heat exchangers which require particularly accurate dimensions of the corrugations with regard to their height.

What we claim is:

1. A device for corrugating a strip, comprising, in combination, a bed, first and second punches operatively interconnected via respective first and second driving camshaft to perform alternately opposite reciprocating motions in a direction perpendicular to a first stationary support element for said first punch, said first element having a slot to allow the passage of said second punch therethrough, the latter having a second support element adapted to perform together with said first punch a motion parallel to said first element, said punches being provided with means to drawn them off their support elements at the moment of feeding the strip to be corrugated, said drawing means including cams mounted on said camshafts, and pushers coacting with the latter, said pushers being each secured to one arm of respective levers, having stationary rocker shafts, and being each connected with another arm to said punches, and means to reciprocate said punches.

2. The corrugating device as defined in claim 1, wherein said arms of the levers are opposite said other arms and are in the form of yokes embracing said camshafts, and mounted on one side are said pushers to draw off said punches, while on their other side there are mounted further pushers that are in permanent resilient contact with said camshafts.