US3606668A

US3606668A - Apparatus for embossing steel strip and method of treating same

Info

Publication number: US3606668A
Application number: US808927A
Authority: US
Inventors: Harold K Young; William O Blanch
Original assignee: Bethlehem Steel Corp
Current assignee: Bethlehem Steel Corp
Priority date: 1969-03-20
Filing date: 1969-03-20
Publication date: 1971-09-21
Anticipated expiration: 1988-09-21
Also published as: BE747433A; CA922977A; NL7003778A; FR2035111A1; DE2012742A1; GB1300815A; FR2035111B1

Abstract

STEEL STRIP IS PASSED THROUGH AN EMBOSSING APPARATUS WHICH PRODUCES A SERIES OF SPACED PROJECTIONS ALONG EACH EDGE OF THE STRIP. THE MALE EMBOSSING MEMBERS EACH COMPRISE A WHEEL HAVING A PLURALITY OF PROTUBERANCES DISPOSED ALONG THE PERIPHERY THEREOF, THE SPACING BETWEEN EACH PAIR OF ADJACENT PROTUBERANCES DIFFERING ABOUT THE PERIPHERY. THE STRIP IS THEN COILED ABOUT A VERTICAL AXIS WHEREBY SUBSTANTIALLY ALL OF SAID PROJECTIONS ABUT UNDERFORMED PORTIONS OF STRIP CONVOLUTIONS ADJACENT THERETO. HEATED GAS IS SUBSEQUENTLY PASSED BETWEEN THE CONVOLUTIONS OF THE COIL TO CHANGE THE CHARACTERISTICS OF THE METAL STRIP, AFTER WHICH THE PROJECTIONS ARE REMOVED FROM THE EDGES OF THE STRIP AND THE STRIP IS TIGHTLY COILED.

Description

Sept. 21, 1971 YOUNG ETAL 3,506,668

APPARATUS FOR EMBOSSING STEEL STRIP AND METHOD OF TREATING SAME Filed March 20. 1969 2 Sheets-Sheet 1 lli-Ml W Hora/d K. Young Herbert Wa/d W/7//'am 0. Blane/7 Sept. 21, 1971 H. K. YOUNG ETAL 3,606,668

APPARATUS FOR EMBOSSING STEEL STRIP AND METHOD OF TREATING SAME Filed March 20, 1969 2 Sheets-Sheet 8 v ANNEALER TIGHT COILER 58 TIGHT 0011.51? .60 V 6 1 WWW WASHER MASHER nous (NAT/PIC ACID) 6'2 INVIiN'I'ORS Haro/dK Young Herbert Wald MMbmOB/anch United States Patent 01 fice tion Filed Mar. 20, 1969, Ser. No. 808,927 Int. Cl. 323p 17/00 US. Cl. 29-423 2 Claims ABSTRACT OF THE DISCLOSURE Steel strip is passed through an embossing apparatus which produces a series of spaced projections along each edge of the strip. The male embossing members each comprise a wheel having a plurality of protuberances disposed along the periphery thereof, the spacing between each pair of adjacent protuberances differing about the periphery. The strip is then coiled about a vertical axis whereby substantially all of said projections abut undeformed portions of strip convolutions adjacent thereto. Heated gas is subsequently passed between the convolutions of the coil to change the characteristics of the metal strip, after which the projections are removed from the edges of the strip and the strip is tightly coiled.

BACKGROUND OF THE INVENTION This invention relates to the treatment of metal strip, and more particularly to an apparatus for producing projections along the edges of a steel strip. It further relates to a method of treating metal strip which includes the step of coiling metal strip about a vertical axis with adjacent convolutions separated by reason of said projections.

There are many processes for treating steel strip which requires the strip to be open Wound, i.e., Wound in such a manner that adjacent convolutions are separated, in order to permit the entire surface of the strip to be exposed to gases which cause a change in the characteristics of the metal strip. Typical of these processes is the chromizing process, in which ferrochromium powder is compacted onto the surface of strip which is subsequently heated in a furnace to a temperature sufficiently high to cause diffusion of said powder into the steel strip to provide an iron-chromium alloy coating thereon. Open coiling prevents welding of the convolutions of the coil and permits intimate contact between the furnace atmosphere and the surface of said coated strip.

In the past, open-Winding was generally accomplished by inserting a pair of zig-zag steel wires or the like between the convolutions of the coil during winding thereof, each wire being spaced about one inch from the top and the bottom edge of the strip, respectively. These wires were removed from the strip while unwinding the coil following the chromizing heat treatment. However, the wires frequently became brittle and, in addition, stuck to the surface of the strip as a result of said heat treatment. Consequently, said wires broke during the unwinding operation. In addition, at least two men were required for the removal of said wire.

It has been suggested that the convolutions of a coil of strip can be separated by providing indentations, and corresponding projections, along the edges of the strip. However, this method of separation appeared impractical, since the projections along the edges of one convolution would frequently nest in the indentations along the edges of an adjacent convolution.

It" is an object of this invention to provide an apparatus for embossing the edges of steel strip whereby said strip can be open wound without the occurrence of nesting.

It is a further object to provide a method of treating steel strip which utilizes such an apparatus.

3,606,668 Patented Sept. 21, 1971 SUMMARY OF THE INVENTION We have discovered that the foregoing objects can be attained by providing an apparatus comprising a shaft, rotatably mounted in a frame, having first and second Wheel members coaxially secured thereto. Disposed along the periphery of each Wheel member is a plurality of spaced protuberances, at least some of the spaces between adjacent protuberances being unequal. Also rotatably mounted in said frame is a back-up roll having a plurality of grooves in the peripheral surface thereof, said grooves being adapted to mate with said protuberances during rotation of said shaft.

Steel strip which has been passed through the apparatus of the invention is characterized by a plurality of spaced projections along each edge thereof. The strip can be coiled about a vertical axis whereby substantially all of said projections abut undeformed portions of strip convolutions adjacent thereto, and the coiled strip then can be subjected to treatment to change the characteristics of the metal strip. In the narrower aspects of the method of the invention, the projections can subsequently be removed from the edges of said strip.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmented front elevation showing salient features of the apparatus of the invention.

FIG. 2 is an enlarged sectional view, taken along the lines 22 of FIG. 1, partially cut away to show details of the subject apparatus.

FIG. 3 is a schematic diagram of the apparatus utilized in a chromizing heat treatment operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, the subject apparatus comprises a framework 10 comprising a pair of vertical channels 12 the upper ends of which are connected by a horizontal channel 14. Said framework is provided with a conventional supporting base (not shown), and further com prises a horizontal bearing plate 16 connected between the vertical channels 12. Secured to the channel 14 and the bearing plate 16 are fixed bearings 18 which house the shaft 20 of a vertically disposed female embossing roll 22. Disposed adjacent to said fixed bearings, and also secured to said channel 14 and bearing plate 16, are horizontally adjustable bearings 24 which house the shaft 26 of a vertically disposed male embossing member 28. Each of said adjustable bearings 24 is provided with a collar (not shown) which threadedly engages a screw 30 connected to a hand wheel 32 the rotation of which moves said bearing horizontally. Thus, the gap between the female roll 22 and the male member 28 can be adjusted to accommodate strip of various gauges. The

shafts

20 and 26 are provided with meshing gears 34 whereby said shafts can be rotated synchronously.

The male embossing member 28 comprises a pair of vertically adjustable hubs 36 which are keyed to the shaft 26. One of said hubs is secured to the lower end of the shaft 26, while the other hub is adapted to be secured to any point along the upper half of said shaft, the exact point being dependent upon the width of the strip to be embossed. Secured to each of the hubs 36 is an embossing wheel 38 having a plurality of spaced protuberances 40 disposed along the periphery thereof. In order to substantially decrease the probability of projections along the edges of a strip nesting in corresponding indentations in adjacent convolutions during coiling of said strip, at least some of the spaces between adjacent protuberances are unequal. Preferably, as is shown in FIG. 2, the spacing differs between every pair of adjacent protuberances. In order to prevent the simultaneous alignment of a projection and an indentation at both the 3 upper and the lower edges of the strip, the upper and lower wheels 38 have their protuberances 40 axially misaligned.

Each of the protuberances 40 comprises a square having one end machined to a blunt point to provide a projection. Each square is inserted into a sleeve 42 which is press fitted into an axial bore in the wheel 38. The inner end of the sleeve 42 is threaded and is provided with a screw 44 whereby the axial position of the square, and hence the extent to which the protuberance 40 projects beyond the periphery of the wheel 38, can be adjusted. The square is secured in position by means of a set screw 46.

The female embossing roll 22 is provided with a plurality of grooves 48 in the peripheral surface thereof. Said grooves are adapted to mate with the protuberances 40, and preferably are axially disposed as shown in the drawings. Said grooves may, however, be circumferentially disposed, each groove being adapted for use with strip of a particular width, in which case there is no need for synchronization of the rotaiton of the male and female members. FIG. 2 shows the projections 49 in a strip 50 passing between a male embossing wheel 38 and a female roll 22 having axial grooves therein.

FIG. 3 shows a typical utilization of the apparatus of the invention, viz, as part of the apparatus used in a chromizing heat treatment. As details of the chromizing process may be found in US. Pat. No. 3,312,546 to E.H. Mayer et al., issued Apr. 4, 1967, and assigned to the assignee of the subject invention, the process will be described herein only broadly.

Steel strip 50 having a coating of ferrochromium powder impacted thereon is placed on the tight coil table 52 of a conventional open winding machine, The strip 50 is pulled through the embossing machine 54 of the invention and open wound on the loose coil table 56 of said open winding machine whereby substantially all the projections 49 along the edges of the strip 50 abut undeformed portions of strip convolutions adjacent thereto. The open coil is then placed in an annealing furnace 58 and heated in a controlled atmosphere, preferably including a halogen gas, to cause diffusion of chromium into the surface of the steel strip 50.

After the heat treatment in said annealing furnace 58, the strip 50 is placed on the open coil table 60 of a second conventional open winding machine, and is passed through a set of masher rolls 62 which remove the projections 49 from the edges of the strip 50. Alternatively, the strip may be passed through a conventional edge-trimming machine. The strip is then washed in a bath 64 of dilute nitric acid to remove therefrom traces of any halides that may have deposited thereon, and tight wound on the tight coil table 66 of said second open winding machine.

Subsequently, the strip may be processed in the usual manner, e.g., skin-rolled, slit and sheared.

We claim:

1. A method of treating metal strip, comprising:

(a) producing a series of spaced projections in said strip only along each side edge thereof, at least some of the spaces between adjacent projections being unequal, the projections along one edge of said strip being longitudinally misaligned relative to the projections along the other edge thereof,

(b) coiling said strip about a vertical axis whereby substantially all of said projections abut undeformed portions of strip convolutions adjacent thereto, thereby separating adjacent convolutions by a distance equal to the height of said projections,

(c) treating the coiled strip, while the coil axis is maintained vertical to change the characteristics of the metal strip, and

(d) passing said strip through rolls which flatten said projections.

2. An apparatus for producing a series of projections in a strip only along the side edges thereof, comprising:

(a) a shaft rotatably mounted in a frame,

(b) first and second wheel members coaxially secured to said shaft,

(c) a plurality of spaced protuberances disposed along the periphery of each of said wheel members, at least some of the spaces between adjacent protuberances being unequal, the protuberances on said first wheel member being axially misaligned with respect to the protuberances on said second wheel member,

((1) a back-up roll rotatably mounted in said frame adjacent to said wheel members, and

(e) a plurality of grooves in the peripheral surface of said back-up roll, said grooves being adapted to mate with said protuberances during rotation of said shaft.

References Cited UNITED STATES PATENTS 2,083,518 6/1937 Lorig 72379X 2,089,892 8/1937 Greulich 72196 2,257,760 10/1941 Myberg 72196X 2,991,550 7/1961 Block 11748X 3,027,628 4/1962 Wilk et al. 29-605 3,222,212 12/1965 Samuel et al. 117107.2 3,290,184 12/1966 Minck 14816 3,453,726 7/1969' Roen 29-609X JOHN @F. CAMPBELL, Primary Examiner V. A. DI PALMA, Assistant Examiner US. Cl. X.R.