US3630334A

US3630334A - Embossing apparatus for curved container surfaces

Info

Publication number: US3630334A
Application number: US824031A
Authority: US
Inventors: John J Connolly
Original assignee: Coyne Cylinder Co
Current assignee: Coyne Cylinder Co
Priority date: 1969-05-09
Filing date: 1969-05-09
Publication date: 1971-12-28
Anticipated expiration: 1988-12-28

Abstract

An embossing apparatus particularly well adapted for embossing symbols on relatively thin walled hollow articles such as containers. An embossing tool is mounted in a holder and its embossing section is rolled over the outer container surface while subjected to low impact forces from an impacting gun. The container is movable in a first direction to permit the embossing of the symbols in a row and the holder allows movement of the embossing section of the tool in a second, transverse direction for the embossing of the symbols in parallel, spaced rows. Means are provided to permit the automatic embossing of symbol sequences such as words.

Description

United States Patent [72] Inventors John J. Connolly, deceased 996,229 6/1911 Elliott l97/6.6 late 01 Millbrae, Calif. by Marie Z. 1,128,225 2/1915 Choate 197/6.7 Connolly, administratrix; 1,504,598 8/1924 Bergen l97/6.7 Richard B. Newhall, El Cerrito, Calif. 3,054,494 9/1962 Rizzetti 197/64 [21] Appl. No. 824,031 3,083,807 4/1963 Travaglio 197/67 [22] Filed May 9,1969 3,485,335 12/1969 McMahon l97/6.7 [45] Patented Dec. 28, 1971 Prima ry Examiner-Robert E. Pulfrey [73] Asslgnee g f Assistant ExaminerClifford D. Crowder an ranc'sco a Attorney-Twnsend and Townsend [54] EMBOSSING APPARATUS FOR CURVED CONTAINER SURFACES 15 Clai s,6 Drawing Figs. ABSTRACT: An embossing apparatus particularly well adapted for embossing symbols on relatively thin walled hol- [52] US. Cl low articles Such as containers An embossing tool is mounted 51 I l in a holder and its embossing section is rolled over the outer 1 8441,5106 container surface while subjected to low impact forces from d is h 197/6 7 an impacting gun. The container is movable in a first direction 1 0 6 to permit the embossing ofthe symbols in a row and the holder allows movement of the embossing section of the tool in a [561 2111x3132?fizslzzaissrzszazfr giiziinzz sf UNITED STATES PATENTS tomatic embossing of symbol sequences such as words. 3,019,723 2/1962 Bauer 101/5 5&-

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SHEET 1 [1F 4 INVENTORS JOHN J. CON NOLLY RICHARD B. NEWHALL TM (DJ 70W M ATTORNEYS 'F'IG..1

PATENTED [H2828 Em SHEET 3 OF 4 FIG-4' FIG-3 'FIG..5.

INVENTORS JOHN J. CONNOLLY BY RICHARD B. NEWHALL ATTORNEYS PATENTEUumenen 3530,1334

SHEET 4 [IF 4 4 5 212555. AIR

I L 15o HAMMER so LEHGZ OSCILLATOR EMBOSSING I STATION ROW POSITIONING FIG-6 CYLA INDEXING INVENTORS JOHN J. CONNOLLY RICHARD B. NEWHALL TWMJ 0.1

ATTORNEYS EMBOSSING APPARATUS FOR CURVED CONTAINER SURFACES BACKGROUND OF THE INVENTION Articles, particularly metallic containers such as cylinders for the storage of gas under pressure, are frequently embossed with letters, numbers and other symbols to identify the contents of the cylinder and the owner thereof. In the past this has usually been performed manually with steel stamps and a hammer.

The relative hardness of metals requires substantial impact forces to emboss the letters and numbers in the surface of the cylinder. If the cylinder is relatively thin walled, as for the storage of gases under relatively low pressures, the forces are often sufficient to dent or otherwise deform the underlying cylinder wall. This gives the cylinder an unsightly appearance and can damage the cylinder wall, thereby creating a danger to persons and property in the vicinity of the charged cylinder.

In addition, hand stamping of the symbols is nonuniform,

gives the cylinders a nonprofessional appearance and is time consuming. Frequently thousands of such cylinders must be embossed so that the economic waste becomes significant.

SUMMARY OF THE INVENTION The present invention provides apparatus for automatically embossing symbols such as letters and numbers on containers and is particularly well adapted for the embossing of relatively thin walled containers without denting, deforming, or otherwise damaging the cylinder walls. In its broadest aspect the apparatus comprises a frame including support means for holding an article such as a pressurized gas storage cylinder, a tube or a pipe. Means mounted to the frame are provided for holding an embossing section of an embossing tool adjacent an outer surface of the cylinder. The holding means are constructed to permit relative motion between the section and the surface so that only a portion of the section is engageable with the surface at any one time. Motion imparting means move the embossing section relative to the surface of the cylinder and impact means engageable with the embossing tool are provided for driving the embossing tool against the surface of the article. Actuation of the impact means thereby causes the sequential embossing of the symbol on the cylinder surface.

In the presently preferred embodiment of the invention the apparatus is adapted for the embossing of symbols on contoured surfaces, particularly on the contoured intermediate surface between a main body portion and a reduced cross section end portion of cylinders. First pivot means permits the pivoting of the holding means and the embossing tool about an axis substantially tangent to the contoured surface whereby the relative motion between the embossing section of the tool and the contoured surface is substantially a rolling motion. Second pivot means mounts the holding means to the frame for pivotal movement of the holding means about the center of curvature of the arcuate surface whereby pivotal movement of the holding means by the second pivot means permits the embossing of the symbols in parallel rows spaced over the arcuate surface.

The impact means apply forces to the tool which are insufficient to emboss the symbol in the article surface if the full embossing section simultaneously engages the article. Thus, the forces exerted at any one time are substantially less than those required when manually embossing the symbols with a stamp and a hammer. Deformation of and possible damage to the cylinder walls from the embossing operation are thereby eliminated.

In addition, the apparatus includes means for advancing different embossing tools towards an embossing station and indexing means synchronized with the first mentioned means for advancing portions of the cylinder surface to the embossing station. Uniformly embossed rows of symbols are thereby automatically obtained.

Thus, the present invention provides for safer gas storage cylinders and gives them a more appealing and professional appearance. Moreover, higher production rates can be obtained from employing the automated equipment of the present invention and an operator can simultaneously supervise as many as two or three embossing machines. The cost of embossing cylinders, particularly large quantities thereof, is thereby substantially reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side-elevational view, with parts broken away, of an embossing apparatus constructed according to the present invention;

FIG. 2 is a front elevational view, with parts broken away, of the apparatus illustrated in FIG. 1;

FIG. 3 is an enlarged, fragmentary side-elevational view in section and is taken on line 33 of FIG. 2;

FIG. 4 is a fragmentary, front elevational view, with parts broken away, and is taken on line 4-4 of FIG. 3;

FIG. 5 is an enlarged, fragmentary sectional view through the cylinder, the embossing tool holder and the embossing tool at the embossing station of the apparatus; and

FIG. 6 is a schematic diagram illustrating the main electric control circuits and the main hydraulic actuating circuit of the apparatus illustrated in FIGS. 1 and 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, an embossing apparatus 10 constructed according to the present invention is supported by an upright frame 12 mounted to a base plate 14 resting on ground 16. The upright frame has a generally U-shaped configuration and is defined by a pair of spaced, vertical posts 18 interconnected by an elevated, transverse beam 20. Sleeves 24 of a vertically movable support structure 22 engage the post and the support structure is suspended from beam 20 with cable 26, A hydraulic actuator 28 is mounted to the beam, engages the cable and thereby permits the raising or lowering of the support structure along posts 18.

A turntable 30 is mounted to base plate 14 and is rotatable about a vertical axis which is disposed in a vertical plane V" defining the center line of the embossing apparatus. An article to be embossed, such as a pressurized gas storage steel cylinder 32, is placed on the platform of the turntable for the subsequent embossing of symbols at a contoured, arcuate surface 34 between a main body portion 36 and a reduced diameter end or neck portion 38. As is more fully set forth below, the embossing of symbols takes place at the intersection between vertical plane V and the portion of arcuate surface 34 facing towards frame I2. The intersection is hereinafter referred to as embossing station."

Still referring to FIGS. 1 and 2, support structure 22 is defined by inwardly extending arms 40 joined to sleeves 24 which, at their inner end, mount a pair of forwardly, (towards cylinder 32) extending support members 42 that terminate at about the center line of cylinder 32 as illustrated in FIG. 1. An elongate mounting plate 44 extends downwardly from each support member 42 and the mounting plates are secured to the support members at adjacent the forward end of the latter.

The mounting plate includes a plurality of aligned, spacedapart bores 46. A pivot pin 48 is secured to one of the bores, say bore 46a, of each mounting plate and projects past the surface of the plate facing the other mounting plate. A holding frame 50, comprising laterally spaced plate members 52 disposed adjacent mounting plates 44 and engaged by pivot pins 48, and a rearwardly extending frame 54, is pivotable about aligned pins 48. The holding frame has a generally U- shaped configuration and is engaged by an upwardly extending spindle 56 secured to frame 54 adjacent a rear end thereof and further engaged by an air motor 58 pivotally mounted to a rearwardly extending portion 60 of support members 42. Thus, pivotal movement of holding frame 50 about pivot pins 48 is controlled and limited by air motor 58 and spindle 56. When the motor is deenergized the holding frame is rigidly maintained at a given position.

An oscillating support assembly 62 for rotatably mounting an embossing tool carrying disc or plate 64 comprises a mounting plate 66 and an upright stiffener 68 secured to the side of the mounting plate opposite from the disc 64. The stiffener includes a cutout 70 'over the center of disc 64 to enable the mounting of the disc to plate 66. The stiffener extends forwardly and terminates at a transverse face plate 72. The face plate extends generally perpendicular to inside surfaces of mounting plate 44 and terminates at flat pivot arms 74 disposed immediately adjacent and interiorly of holding frame plate members 52. The pivot plates are pivotally connected to members 52 by pivot pins 76. For reasons more fully set forth hereinafter the axis 76A of the pivot pins is tangential to arcuate cylinder surface 34 at the embossing station.

Oscillating means 78 include a pneumatic actuator 80 pivotally mounted to holding frame 54 adjacent the rear end thereof and having a retractable rod 82 pivotally connected to the rear end of mounting plate 66. The oscillating means thus controls and limits the pivotal movement of the oscillating support assembly, including disc 64, about pins 76.

Disc 64 is parallel to mounting plate 66 of the oscillating support assembly and is rotatable about an axis perpendicular to the support plate. A hearing 84 disposed in cutout 70 rotatably secures the disc to plate 66.

Referring now to FIGS. 1 through 4, and particularly to FIGS. 3 and 4, mounting plates 44 of support structure 22 are interconnected by a horizontally disposed platform 86. The platform projects past the vertical axis of cylinder 32 and mounts a vertically disposed bearing 88 which has its axis aligned with the axis of rotation of turntable 30. A downwardly depending hollow mounting sleeve 90 is rotatably received in bearing 88 and preferably includes a rubber lining (not shown) for engaging cylinder neck 38 and rigidly securing the upper end of the cylinder without damaging threads applied to the exterior surface of the cylinder neck. Details of the construction of bearing 88 and mounting sleeve 90 are well known to those skilled in the art and are, therefore, not further described herein.

A cylinder indexing mechanism 92 is provided for rotating the cylinder on turntable 30 about its vertical axis in predetermined angular increments. The indexing mechanism is powered by a pneumatic actuator 94 mounted to platform 86 adjacent a mounting plate 44 and having a reciprocable push rod 96. A free end of the push rod is pivotally connected to an end of a rocker arm 98 which is in turn pivotally mounted to the underside of platform 86. The other end of the rocker arm includes a cam surface which extends generally radially from the rocker arm in a direction transverse to the axis of the arm. The cam surface engages a projection (not shown) of a rachet mechanism (not shown) mounted to bearing 88 and constructed to rotatably advance sleeve 90 in increments which are a function of the magnitude of the pivotal movement of rocker arm 98. Such mechanisms are known and are therefore not further described herein.

Pneumatic actuator 94 is energized to move push rod 96 downwardly to rotatably advance or index sleeve 90 and cylinder 32. The magnitude of the advance is determined by the axial travel of the push rod. That travel is limited by stop means 100 mounted to the surface of the adjacent plate member 52 facing towards the embossing station.

The stop means includes a mounting bracket 102 which has a generally arcuate flange 104 to which threaded sleeves or nuts 106 are secured at spaced intervals. Threaded bolts, 108, 109 and 110 are engaged by the nuts and project past the nuts various distances. The bolts and nuts are positioned and spaced so that one bolt is aligned with the axis of push rod 96 whenever holding frame 50, and with it plate member 52 mounting bracket 102, is in a position in which a row of symbols is embossed in the arcuate surface 34 of cylinder 32. As more fully set forth hereinafter the embossing apparatus of the present invention permits the embossing of a plurality, spaced apart rows over that cylinder surface.

As the spacing of such rows from the cylinder axis increases the angular increments the cylinder must be indexed for embossing a symbol of a given size decreases.

Bolts

108, 109 and 110 are consecutively longer and, thereby, reduce the axial travel of push rod 96 as they become aligned with the push rod during the pivotal movement of plate member 52 and holding frame 50 in a counterclockwise direction, as viewed in FIG. 3. Thus, the rachet mechanism (not shown) advances sleeve and the cylinder through lesser angular increments each time actuator 94 is energized as stop means shortens the axial travel of push rod 96. The spacings between adjacent indexing increments of the cylinder remain constant to assure a uniform, equally spaced lettering or numbering of the cylinder surface.

Referring now to FIGS. 1, 5 and 6, disc 64 includes a plurality of bushings 112 which are equally spaced from a center shaft 114 of the disc and which have uniform distances between their centers. The axis of the center shaft lies in vertical plane V. An embossing tool 116 includes a cylindrical body 118 fitting snugly within the bore of bushing 112, a generally square head 120 and an embossing section 122. The distance between the center of shaft 114 and the center of bushing 112 is exactly equal to the radial distance along plane V between the shaft and the axis 76A of pivot pin 76 interconnecting plate members 52 and pivot anns 74. Consequently, when the axis of a bushing 112 and an embossing tool 116 lies in the vertical plane V at the embossing station, the axis of the bushing and the tool intersects the axis 76A of pivot pin 76 at the embossing station.

When actuator 80 of oscillating means 78 is energized to oscillate or pivot support assembly 62 and disc 64 about pivot pin 76 and the embossing tool 116 is driven towards arcuate surface 34 of cylinder 32, embossing section 122 of the tool prescribes a rolling motion over the arcuate cylinder surface. A low impact hammer 124 having a driver 126 is mounted to face plate 72 of the oscillating support assembly 62 (see FIG. 1) and is energized while disc 64 at the support assembly oscillates about pivot axis 76A. At any moment during the pivotal movement of the disc only a portion of embossing section 122 engages the arcuate surface so that the impact forces exerted by driver 126 can be much lower than if the whole embossing section simultaneously engaged the arcuate surface of the cylinder. With the lower impact forces it is possible to emboss letters, even large size letters, without deforming or denting even relatively thin walled cylinders such as low pressure (about 150 psi.) gas storage cylinders having diameters between about 6 to about 12 inches and a wall thickness of about Va inch.

A tool holder 128 is provided to prevent vibrations of the embossing machine and disc 64 caused by impact hammer 124 from shaking loose the embossing tools not driven by the impact hammer. The holder comprises a flat plate 130 having a nose portion 132 engaged in a shallow groove 134 of embossing toolhead 120. Plate 130 is loosely engaged by a bolt 136 threaded into disc 64 so that the nose portion can be moved into and out of engagement with groove 134. A compression spring 138 biases the holder towards the embossing tool and maintains nose portion 132 in groove 134 even if the tool and the plate are subjected to substantial vibration. The holder is readily disengaged from the embossing tool by pulling it away from the tool against the force of compression spring 138.

With oscillating support assembly 62 and disc 64 in the angular position indicated in FIG. 5, symbols are embossed in the arcuate cylinder surface 34 each time impact hammer 124 is energized and the oscillating assembly is pivoted through an angle of between about 15 to about 60 degrees about pivot axis 76A. Thereafter, the cylinder indexing mechanism 92 is energized to rotatably index the cylinder through sufficient arc to place another area of the arcuate surface at the embossing station to permit the embossing of additional symbols.

To permit the embossing of different symbols to form words, numbers, etc., embossing tools with the required symbols are sequentially inserted in adjacent bushings 112 of disc 64 and the disc is advanced by rotating it through an are equal to the angular spacing between adjacent bushings. The advance of the disc can be accomplished with any one of many known means, such as a disc advancing or indexing mechanism 140 which acts on the periphery of the disc. it is preferred to provide disc positioning means such as a pneumatically actuated indexing finger 142 to accurately and positively position the selected bushing 112 and embossing tool 116 at the embossing station. Words, numbers, combinations thereof, and other desired symbols can thus be sequentially embossed in a row on the arcuate surface of the cylinder.

To emboss a plurality of parallel, spaced-apart rows of letters, numbers, etc., on the cylinder holding frame 50 is pivotally moved about pivot pin 48 by actuating air motor 58 to lower spindle 56 and holding frame 50. During the pivotal movement of the frame about pivot pin 48 oscillating support assembly 62, disc 64 and embossing tool 116 move through an arcuate path the center of which is the axis of pin 48. Pin 48 is positioned so that it is at the center of curvature of arcuate cylinder surface 34. Generally, the arcuate cylinder portion has two circularly arcuate sections, the first section beginning at neck 38 and extending from the cylinder axis to a second circularly arcuate section interconnecting the first section with the vertical cylinder walls of main cylinder body 36.

Manufacturing tolerances in the production of the cylinders or the need to include a small portion of the second circularly arcuate cylinder surface section sometimes requires the positioning of the axis of pivot pin 48 at a position slightly above,

below, or sideways of the true center of the first circular section. Nevertheless, the pivot axis remains at about the center of curvature of the first arcuate cylinder surface section.

Assuming the axis of pivot pin 48 to be at the exact center of the first circularly arcuate section and that that section is a true arcuate surface, pivotal movement of holding frame 50 about pin 48 causes axis 76A (FIG. 5) of pivot pin 76 to move parallel to and along the intersection between arcuate surface 34 and plane V. Consequently, axis 76A is at all times tangent to the arcuate surface at the embossing station. At each position of the embossing tool 116 on the arcuate surface over the extent of the first circularly arcuate section actuation of oscillating means 78 and impact hammer 124 causes the embossing of the embossing section 122 of the tool disposed at the embossing station. By pivotally moving holding frame 50 about pin 48 parallel, spaced-apart rows of embossed symbols can be obtained. Depending upon the physical size of the cylinder and the width of arcuate cylinder surface 34 a plurality of two or more symbol rows can be embossed.

As briefly alluded to at the beginning of this specification, mounting plate 44 of support structure 22 includes a plurality of spaced-apart bores 46. Similarly, plate members 52 of bolding frame 50 include a plurality of spaced-apart bores 144. Pivot pin 48 can be removed from bore 46A and inserted in one of the other bores in mounting plate 44. By aligning a corresponding bore in plate member 52 and extending pin 48 therethrough holding frame 50, disc 64 and embossing tool 116 become pivotal about that point. Such other points are chosen to guide the holding frame, the disc and the embossing tool through arcs corresponding to arcs of contoured cylinder portions of cylinders of different sizes and/or configuration. The embossing apparatus of the present invention can thus be adapted for use with cylinders of various sizes, shapes and configurations.

Referring now to FIG. 6, the control circuitry employed by the embossing apparatus is described in detail. Disc 64 includes a plurality, say four relatively small diameter bores 146 which are disposed on the radiant connecting the center of shaft 114 with the axis of bushing 112. Four electrical sensor switches 148 are mounted to mounting plate 66 (not shown in FIG. 6) of oscillating support assembly 62 and so positioned relative to the axis of shaft 114 that the sensor arms of the switches are aligned with the disc bores 146 when the disc rotates about the shaft. Three of the sensor switches are electrically coupled to electrically controlled shutoff valves 150 which are in fluid communication with a source 152 of pressurized air and three

pressure regulators

154, 155 and 156. Air pressure at the downstream outlet of the regulators varies by predetermined amounts. For example,

regulators

154, 155 and 156 may provide air pressures of 50 p.s.i., 75 p.s.i., and I00 p.s.i,, respectively, at their downstream outlets. Other increments in the pressure rating of the regulators may, of course, be employed. The downstream outlet of the regulators is connected to the air inlet of impact hammer 124 and to pneumatic actuator of oscillating means 78.

A button 158 is inserted in one of the three innermost disc bores 146 so that one or the other of the inner three sensor switches 148 is closed whereby the corresponding shutoff valve 150 is opened and air pressure is supplied to the impact hammer. Driver 126 of the hammer is thereby energized to drive embossing tool 116 (not shown in FIG. 6) against the arcuate surface 34 of cylinder 32. While the impact hammer is energized oscillating means 78 is also actuated to pivot oscillating support assembly 62, disc 64 and the embossing tool about pivot axis 76A (best seen in FIG. 5) to obtain the aforementioned rolling motion of embossing section 122 over the arcuate cylinder surface.

Different size symbols, such as lb-inch, 4-inch and 36-inch letters, can be formed by the embossing section of the embossing tool. The larger the symbol size the greater the driving force required from impact hammer 124 since a greater area of the embossing tool section is in engagement with the arcuate cylinder surface at any instant of time. To maintain the unit pressure of the engaged embossing section substantially constant irrespective of the letter size, the above-described selection of the impact hammer air pressure by means of pressure regulators, shutoff valves and sensor switches is provided. Thus, if the letter being embossed is of a 4-inch size button 158 is inserted in the innermost disc bore 146 so that the innermost sensor switch 148 is closed and shutofi" valve 150 associated with pressure regulator 154 supplies the impact hammer with 50 p.s.i. air. If the letter size on the embossing tool were it; inch button 158 is inserted in the third disc bore 146 from shaft 114 so that impact hammer 124 receives air at p.s.i., from pressure regulator 156. it will be clear that additional regulators and sensor switches can be provided if desired.

This arrangement permits the embossing of different size symbols in the arcuate cylinder surface 34 without denting the cylinder, even if that surface is relatively thin because the unit pressure remains constant while the total impact force from hammer 124 is relatively low. The applied unit pressure remains constant since the forces exerted by driver 126 of the impact hammer are spread over a greater area if the letter being embossed is larger. At the same time the symbols are embossed into the cylinder to equal depths to give them an appealing and professional appearance.

Shut-off valves preferably include a built-in timing device to limit the air supply to impact hammer 124 and oscillating means 78 to the time required for one complete oscillation of support assembly 62. Alternatively, mechanical controls such as cam surfaces can be provided to cause a shutoff of the air pressure supplied to the impact hammer and the oscillating means. Their construction is known to those skilled in the art and they are therefore not further described or illustrated herein.

Sensor switches 148 are further connected through a second shutoff valve 160 which is in fluid communication with air source 152 and has its downstream outlet coupled to disc advancing mechanism 140 and indexing finger 142. The downstream side of the shutoff valve is also in fluid communication with pneumatic cylinder indexing mechanism 92.

The electric circuitry from sensor switches 148 coupled with shutoff valve 160 and the fluid circuitry of the shutoff valve is so arranged that the disc advancing mechanism is energized after the end of an embossing cycle during which the oscillating support assembly 62 goes through a complete oscillation while impact hammer 124 'drives the embossing tool against the cylinder wall. At the end of the advance of disc 64 by mechanism 140 the indexing finger is engaged with the disc to accurately position the next embossing tool at the embossing station.

While disc 64 is repositioned for the embossing of the next symbol, the cylinder indexing mechanism 92 is also energized to advance the next portion of the cylinder surface to the embossing station. Thereafter, the machine goes through the next embossing cycle as already described.

If two or more spaced apart words are to be embossed the bushing between the last embossing tool of the first word and the first embossing tool of the second word is left empty, and no buttons 158 are inserted in disc bores 146. Thus, when the empty bushing arrives at the embossing station, the impact hammer 124 and the oscillating means 78 are not energized and shutoff valve 160 fluidly connects disc advancing mechanism 140, indexing finger 142 and cylinder indexing mechanism 92 to advance both disc 64 and cylinder 32 an additional increment. Thereafter embossing of the second word commences as described.

If a second row, spaced below and parallel to the first embossed row is to be embossed on the arcuate cylinder surface 34 a button 158 is inserted in the fourth or outermost disc bore 146 to actuate the outermost sensor switch 148. That sensor switch controls a shutoff valve 162 mounted in the pressure line from air source 162 to air motor 58 controlling the angular inclination of holding frame 50 and its pivotal movement about pivot pin 48. The presence of a button in the outermost disc bore 146 opens .valve 162 and holding frame 50 is pivoted downwardly through the actuation of air motor 58. The limit of the pivotal movement is controlled by cam surfaces, limit switches acting on shutoff valve 162, motor 58 or directly on holding frame 50. The automatic control of the air motor can be replaced by manual control (not shown) if desired.

Turning now to the operation of the embossing apparatus, pivot pins 48 are inserted in holes 46 of mounting plate 44 and' the holes 144 of plate members 52 corresponding to the size and configuration of the cylinder to be embossed. Air motor 58 is actuated to raise holding frame 50 to its uppermost position, for example, its horizontal position, and the oscillating means is placed into its starting position at which rod 82 is fully retracted into cylinder 78. Embossing tools 116 are inserted in bushings 112 in the proper sequence to form words, numbers, etc. Spacings between adjacent words or numbers are obtained by leaving a corresponding bushing empty. Buttons 158 are inserted in disc bores 146as described above to obtain the correct air pressure to which impact hammer 124 is subjected.

Support structure 22 is raised by energizing hydraulic actuator 28 via air from air source 152 and with the help of manual controls (not shown). A cylinder 32 is placed on turntable 30, is aligned with the axis of the turntable as by stops (not shown) on the face of the turntable, and the manual controls are operated to lower support structure 22 until cylinder neck 38 is engaged by neck mounting sleeve 90 and is firmly retained therein. Disc 64 is rotated until the first letter, number, or other symbol of the first word in the first row is at the embossing station.

A control switch (not shown) is closed to start the embossing of the first letter according to the previously described sequence. Letter after letter in the first row is now embossed, with spaces left at the appropriate places, until the end of the first row is reached. At that point air motor 58, as controlled by shutoff valve 162 and the associated sensor switch 148 is automatically energized to position the next bushing and embossing tool at the second row of the arcuate portion 34 of the cylinder. This continues until the embossing of the cylinder has been completed.

If each row contains an insufficient number of symbols to cover the full length of the row, electric and fluid control circuitry is provided to stop the actuation of impact hammer 124,

oscillating means 78, and disc advancing mechanism 140 after air motor 58 has repositioned the holding frame. The cylinder is manually rotated to its proper starting position so that the second and subsequent rows embossed thereon are symmetric with the embossings in the first row. For that purpose a hand reel (not shown) an be provided and connected with cylinder neck mounting sleeve to facilitate the repositioning of the cylinder. The hand reel may be provided with position indicat ing means as, for example, a degree scale so that the scale may be set according to templates, tables, etc., supplied to the embossing machine operator. Alternatively, automatic controls such as punched tape, a special purpose computer, etc., can be provided to place the cylinder in its proper position before commencing the embossing of the second row.

To increase the speed with which the symbols are embossed it is desirable to advance or index disc 64 and cylinder 32 as rapidly as possible. The inertia of the disc and cylinder can result in their overtraveling the indexed position which would result in a misplacement of the embossed symbols. it is, therefore, preferred to construct the disc of a lightweight material such as aluminum and provide an air controlled brake 164 (P16. 1) acting on disc center shaft 1 14 and applied as soon as disc advancing mechanism is deenergized. Similarly, it is preferred to apply an air-operated brake, or a continuously spring biased brake 166 (FIG. 2) to the turntable or to cylinder neck mounting sleeve 90 to prevent an overtravel of the cylinder after cylinder indexing mechanism 92 is deenergized.

While one embodiment of the invention has been shown and described, it will be obvious that other adaptations and modifications can be made without departing from the true spirit and scope of the invention. For example, a number of electric and/or pneumatic control and actuating circuits can be constructed to provide the functions required for the operation of various components of the apparatus. Moreover, a greater or lesser portion of the apparatus functions can be automized and/or automatically controlled as through the above-referred-to computer means.

lt is further not necessary that the machine stands in the illustrated upright position. For high volume production the machine can be placed sideways so that upright frame 12 is in an inclined or a horizontal position whereby cylinders 32 can be rolled towards turntable 30 in a mass production line manner.

Additionally, the use of the apparatus is not limited to the embossing of thin walled cylinders. its advantages are obtained when used in the embossing of high pressure heavy steel wall cylinders, such as compressed oxygen bottles for example, for the embossing of metallic pipe, and for the embossing of other articles in which the embossing should be uniform and neat and/or in which the forces applied to the embossing tool should be controlled to prevent damage or disfiguration of the article.

It is claimed:

1. Apparatus for embossing symbols in a section of a surface portion of an article which is substantially circularly arcuate in at least one direction, the apparatus comprising: a frame including support means for rigidly positioning the article, carrying means mounted to the frame for holding an embossing section of an embossing tool adjacent the surface section of the article, means for pivoting the carrying means and the embossing section in a plane substantially perpendicular to the surface portion about an axis substantially tangent to the surface portion so that only a portion of the embossing section is engaged with the surface portion at any one time, second pivot means mounting the carrying means to the frame, the second pivot means having a pivot axis substantially at the center of curvature of the contoured surface section whereby pivotal movement of the carrying means by the second pivot means permits the embossing of the symbols in parallel, rows spaced over the contoured surface section, and impact means engageable with the embossing tool for driving the embossing tool against the surface section of the article, whereby actuation of the impact means causes the sequential embossing of the symbol on the article surface portion.

2. Apparatus according to claim 1 wherein the second pivot means includes means for adjusting the relative position of its pivot axis whereby the pivotal radius prescribed by the holding means can be adjusted to adapt the holding means for motion over arcuate surfaces having varying centers of curvature.

3. Apparatus for embossing letter symbols and the like on relatively thin walled hollow articles having an arcuately contoured surface, the apparatus comprising: a frame having an embossing station and including means for positioning the article so that the arcuate surface is disposed at the embossing station; an embossing tool carrying plate mounted to the frame, the plate including means for receiving a plurality of removable embossing tools, the tool receiving means being mounted on a circle centered on an axis of the plate, means mounting the plate for rotation about the axis thereof, advancing means engaging the plate and rotating the plate in increments equaling the spacing between adjacent tool receiving means, indexing means synchronized with the advancing means for indexing the article with respect to the embossing station in predetermined increments when the advancing means rotates the plate for the automatic embossing of a row of symbols on the arcuate surface, and means permitting pivotal movements of the plate about an axis substantially tangent to the arcuate surface at the embossing station, means for oscillating the carrying plate about the pivot axis, and impacting means mounted at the embossing station for engagement with the embossing tool and for driving the embossing tool against the arcuate surface, whereby the simultaneous operation of the oscillating means and the impacting means causes sequential embossing of the symbol and enables the forces exerted by the impact means to be maintained sufficiently small to prevent a deformation of the article wall underlying the driven embossing tool.

4. Apparatus according to claim 3 including spacing means connected to the frame and mounting the plate for movement of the embossing tool at the embossing station along the arcuate surface in a direction substantially parallel to the arcuate surface and transverse to the indexing direction of the article for spacing the embossed symbols in a row, the spacing means including means for adjusting the motion path of the plate and the tool to permit the movement of the tool along differently curved arcuate surfaces.

5. Apparatus for embossing symbols on cylindrically shaped containers having a main body portion, a reduced diameter end portion, and an intermediate portion interconnecting the main body with the end portion, the apparatus comprising:

a frame including means supporting the container and positioning the intermediate portion adjacent an embossing station, the supporting means enabling rotatable movement of the container about its axis,

a rotatable member for receiving a plurality of spaced-apart embossing tools and positioning a tool at a time at the em bossing station,

mounting means for mounting the member to the frame, the mounting means including spacing means permitting movement of the member relative to the container along a path substantially parallel to the intermediate portion in a plane which is parallel to the container axis and connects the axis and the embossing station so that an embossing section of an embossing tool at the station can be moved along and substantially parallel to the outer surface of the intermediate container portion,

means for rotatably indexing the container by a predetermined increment,

means for intermittently rotating the member in synchronism with the indexing of the container for changing the embossing tool at the station, and

impact means positioned at the embossing station for subjecting the embossing tool to a multiplicity of low magnitude impacts.

6, Apparatus according to claim 5 wherein the outer surface of the intermediate container portion intersected by the plane is substantially circularly arcuate, and wherein the spacing means comprises a pivot arm mounted to the frame and having a pivot axis perpendicular to the plane and positioned at a point substantially equidistant to the intersection of the outer surface of the intermediate container portion and the plane, and means interconnecting the member and the pivot arm, whereby pivotal movement of the arm causes movement of the embossing tool along the exterior surface of the intermediate portion.

7. Apparatus according to claim 6 including means for varying the relative position of the pivot axis of the pivot arm and the spacing between the pivot axis of the arm and the member to enable movement of the embossing tool along arcuate surfaces having differently positioned centers of curvature.

8. Apparatus according to claim 6 including means operatively coupled with the pivot arm for adjusting the incremental indexing steps of the container to decrease the angular rotation of the container during each indexing step as a function of increases of the distance between the embossing tool at the embossing station and the container axis.

9. Apparatus according to claim 6 wherein the indexing means comprises: drive means engaging the reduced-diameter end portion of the container, the drive means including a fluid actuator, and means responsive to the angular position of the pivot arm for adjusting the effective stroke of the fluid actuator whereby the angular advance of the container is varied according to the distance between the embossing tool at the embossing station and the container axis.

10. Apparatus according to claim 5 including oscillating means for pivotally moving the member about an axis substantially tangent to the outer surface of the intermediate portion at the embossing station while the impact means drives the embossing tool at the embossing station whereby the symbol is sequentially embossed and the magnitude of the force of each impact by the impact means is sufficiently low to prevent deformation of the intermediate portion of the container.

11. Apparatus for embossing metallic cylinders having a large diameter body, a small diameter neck and a contoured intermediate portion between the neck and the body, the apparatus comprising:

a support structure,

means connected to the support structure for mounting the cylinder for rotation about the longitudinal axis of the cylinder,

a rotatable member including a plurality of embossing tool receiving means,

member mounting means carried by the support structure and placing a receiving means adjacent the contoured surface of the intermediate cylinder portion at an embossing station, the member mounting means including means for pivoting the member about an oscillating axis substantially tangent to the contoured surface at the embossing station, the member mounting means further permitting movement of the member parallel to the contoured surface in a plane coinciding with the cylinder axis and intersecting the contoured surface at the embossing station,

advancing means for sequentially positioning a different receiving means at the embossing station,

indexing means for rotatably indexing the cylinder at the embossing station, the indexing means being synchronized with the advancing means,

low impact embossing tool drive means mounted at the embossing station for forcing the embossing tool against the contoured surface, and

oscillating means for pivoting the member about the osci|- lating axis while the drive means is energized to sequentially engage an embossing section of the embossing tool with the contoured surface whereby the impact magnitude of the drive means can be maintained sufficiently low to prevent a deformation of the intermediate cylinder portion by the driven embossing tool.

12. Apparatus according to claim 11 including regulating means for adjusting the impact magnitude of the drive means whereby the unit area pressure exerted by the embossing tool against the contoured surface can be maintained constant irrespective of the configuration of the embossing section of the embossing tool.

13. Apparatus according to claim 11 wherein the member comprises a rotatable disk mounted to the member mounting means, wherein the receiving means comprises a plurality of embossing tool guides mounted along the periphery of the disk on a circle centered at the axis of the disk, and wherein the advancing means includes means for intermittently advancing the receiving means to the embossing station by rotating the disk through a predetermined arc.

14. Apparatus according to claim 11 including first locking means for preventing movement of the member while an embossing tool is positioned at the embossing station, and second locking means for preventing rotation of the cylinder while the low impact drive means is energized.

15. Apparatus according to claim 11 wherein the member mounting means comprises mounting plates rotatably connecting the member and mounted to the support structure for pivotal movement of the member about an axis perpendicular to the plane and substantially tangent to the contoured cylinder surface, and wherein the mounting plate and the support structure include means for adjusting the relative position of the mounting plate pivot axis to permit movement of the plate parallel to the plane along contoured surfaces having varying degrees of curvature.

t it

Claims

5. Apparatus for embossing symbols on cylindrically shaped containers having a main body portion, a reduced diameter end portion, and an intermediate portion interconnecting the main body with the end portion, the apparatus comprising: a frame including means supporting the container and positioning the intermediate portion adjacent an embossing station, the supporting means enabling rotatable movement of the container about its axis, a rotatable member for receiving a plurality of spaced-apart embossing tools and positioning a tool at a time at the embossing station, mounting means for mounting the member to the frame, the mounting means including spacing means permitting movement of the member relative to the container along a path substantially parallel to the intermediate portion in a plane which is parallel to the container axis and connects the axis and the embossing station so that an embossing section of an embossing tool at the station can be moved along and substantially parallel to the outer surface of the intermediate container portion, means for rotatably indexing the container by a predetermined increment, means for intermittently rotating the member in synchronism with the indexing of the container for changing the embossing tool at the station, and impact means positioned at the embossing station for subjecting the embossing tool to a multiplicity of low magnitude impacts. 6, Apparatus according to claim 5 wherein the outer surface of the intermediate container portion intersected by the plane is substantially circularly arcuate, and wherein the spacing means comprises a pivot arm mounted to the frame and having a pivot axis perpendicular to the plane and positioned at a point substantially equidistant to the intersection of the outer surface of the intermediate container portion and the plane, and means interconnecting the member and the pivot arm, whereby pivotal movement of the arm causes movement of the embossing tool along the exterior surface of the intermediate portion.

11. Apparatus for embossing metallic cylinders having a large diameter body, a small diameter neck and a contoured intermediate portion between the neck and the body, the apparatus comprising: a support structure, means connected to the support structure for mounting the cylinder for rotation about the longitudinal axis of the cylinder, a rotatable member including a plurality of embossing tool receiving means, member mounting means carried by the support structure and placing a receiving means adjacent the contoured surface of the intermediate cylinder portion at an embossing station, the member mounting means including means for pivoting the member about an oscillating axis substantially tangent to the contoured surface at the embossing station, the member mounting means further permitting movement of the member parallel to the contoured surface in a plane coinciding with the cylinder axis and intersecting the contoured surface at the embossing station, advancing means for sequentially positioning a different receiving means at the embossing station, indexing means for rotatably indexing the cylinder at the embossing station, the indexing means being synchronized with the advancing means, low impact embossing tool drive means mounted at the embossing station for forcing the embossing tool against the contoured surface, and oscillating means for pivoting the member about the oscillating axis while the drive means is energized to sequentially engage an embossing section of the embossing tool with the contoured surface whereby the impact magnitude of the drive means can be maintained sufficiently low to prevent a deformation of the intermediate cylinder portion by the driven embossing tool.