The present invention relates to aerosol valve mounting cups into which are mounted aerosol valves and which cups are in turn mounted onto the tops of aerosol product containers. More particularly the present invention relates to a new method of manufacturing said mounting cups, and the resultant cups.
The well known and long existing aerosol valve mounting cup is generally a metal member having an outer circular channel that is placed over the circular bead of the aerosol can defining the opening into the aerosol can. The outer side of the channel terminating in a circular edge is commonly known as the skirt of the mounting cup and is crimped onto the can bead with a sealing medium (sleeve gasket, laminated gasket, cut gasket, coated gasket, etc.) positioned in between the channel and can bead.
The interior area of the mounting cup extends down into the can opening and has an upstanding pedestal portion into which is mounted and captured the aerosol valve itself. The dispensing valve stem in the case of a male valve extends upwardly through a central opening in the pedestal. A female valve uses the same basic mounting cup design.
Prior art mounting cups have traditionally been manufactured by forming metal blanks and performing a number of pressing/drawing operations on the metal blanks to arrive at the mounting cup shape. The skirt height of the mounting cup channel is viewed to be critical in relation to the can bead dimensions and also because of hopper feed bowls and other assembly equipment controlled by skirt height. In order to obtain the specified skirt height, mounting cups have been manufactured initially leaving excess metal material at the outer edge. The mounting cup is then passed through a late stage trimming station which cuts material from the extended outer edge to obtain the specified and critical skirt height in the finished mounting cup. Even under such circumstances, the outer edge/lip of the skirt will have an undesirable lack of evenness known as earring.
Given the hundreds of millions of mounting cups produced each year, it can easily be appreciated that there is a large excess material cost involved in the metal trimmed from the outer edge of each mounting cup. There is also the additional cost involved in requiring a trimming station in each production line.
Accordingly, it would be highly desirable to eliminate the need to trim the mounting cup edges and, thus, the need for the trimming station. It would also be desirable to minimize the presence of earring, or skirt height variation, in the final cup.
The present invention produces mounting cups that do not require the aforesaid final trimming operation, and yet obtains a carefully controlled skirt height, preferably with a substantially even outer edge with minimized earring.
In the method of the present invention, blanks, preferably circular discs, are initially cut from a sheet of steel, tinplate or aluminum, including laminated or coated versions thereof. Non-circular blanks can be used in the present invention, but are less desirable because of reasons including the need for more complicated pressing/drawing equipment that requires die alignments and equipment maintenance beyond that where circular blanks are used, and because of potentially excess material cost from the non-circular blank shape.
The circular discs are cut to a precise diameter that, along with other aspects of the present invention relating to a “bumping” operation, results in the final mounting cup with no trimming operation, with a carefully controlled specified skirt height, and preferably with a substantially even skirt edge.
The circular disc is then drawn to a preform for the mounting cup in a first preform press. The cutting of the disc may be carried out by a cutting die at the first preform press. The preform is essentially in a “high hat” configuration with a channel and skirt formed but with no pedestal yet formed, for example. The channel in the preform (and in the final mounting cup) may be rounded, flat or multi-radiused, for example. The edge of the skirt will have a wave or earring, the extent of which will depend upon the grade, temper and structure of the cup material being used and the processing to obtain the channel and skirt in the preform.
The preform is then moved to further press/draw stations in a separate press for further forming operations, for example, the conventional and well-known reverse, reduction and sizing operations, among others, including, for example, piercing, upturning, roll-over and dimpling operations. These operations may be carried out at sequential stations in a belt fed or feed bar transfer press as disclosed herein but other forms of press systems could likewise carry out the methods of the present invention. The essential “bumping” operation of the present invention may be advantageously carried out at the sizing station or at the reverse or reverse draw station, but also could be carried out at other forming stations, for example, as referred to above, in the press or at a separate dedicated “bumping” station.
In a first embodiment of the method of the invention, the essential bumping operation is carried out in a sizing station, for example of a transfer press, after the preform has passed through reverse and reduction press stations. For example, the partially formed mounting cup with its pedestal portion now added is belt fed to the sizing station. The reverse and reduction stations do not affect the skirt height of the preform whose height has been specified. At the sizing station, the sizing die, sizing pad and sizing punch establish the dimensions and configuration of the mounting cup radially inward of the channel skirt. As this sizing is occurring, a centering ring with a cut-out near its outer periphery, or a separate (or integral) bumping ring, acts to bump (meaning here to strike, hit upon) the edge/lip of the mounting cup skirt to reduce/control the height of the skirt to its specified dimension, and, preferably, at the same time to even out the skirt edge/lip to the specified dimension to minimize or eliminate earring. The resulting bumped edge may be characterized by reformed metal, the edge having a shiny area and/or a slightly thicker cross-section resulting from the bumping.
In a preferred second embodiment of the method of the invention, the essential bumping operation is carried out in a reverse or reverse draw station, for example of a transfer press. As in the first embodiment, a circular disc is employed that has been cut to a predetermined specified precise diameter that will result (without a trimming operation) in a final mounting cup and that will have a carefully controlled specified skirt height, and preferably that will have an even or substantially even skirt edge. The disc is drawn at a first cupping or preform press into a mounting cup preform having a channel, a skirt having a terminating edge/lip, and a “high hat”. The skirt edge/lip of the preform, usually, but not necessarily, will have an unevenness or earring about its perimeter. The mounting cup preform is passed to a transfer press where it is received at its first station, a reverse or reverse draw/bumping station. This station has circular or other tooling that inverts the “high hat” while a circular centering ring or bumping ring, preferably with a notch or cut-out with an upper wall extending about its circumference near its base, or a separate (or integral) bumping ring, bumps the edge/lip of the mounting cup preform skirt to reduce/control the height of the skirt to its specified dimension, and, preferably, at the same time, to also even out or substantially even out the skirt edge/lip to minimize or eliminate earring. The inverted or drawn mounting cup is passed to further forming stations of the transfer press, for example, to reduction, sizing, coaxing, piercing, upturning, roll over and dimpling stations that provide conventional metal forming operations to provide a finished mounting cup. As in the case of the first embodiment, the resulting bumped terminating edge may be characterized by reformed metal, the edge having a shiny area and/or a slightly thicker cross-section resulting from the bumping. Other configurations of tooling may be used for the bumping, as long as they operate to set the correct skirt height and preferably eliminate or minimize any unevenness or earring. No trimming is thereafter needed or used to obtain the proper skirt height and substantial material and cost savings are thereby realized.
In a “coaxing”/pinch cut station that can be employed following the sizing/bumping station employed in the first example of the first transfer press, or following the sizing station of the second example of the second transfer press, the skirt near the skirt edge is angled inwardly and further has a coined or embossed inward angle placed on the outside edge of the skirt. A burr-free outside skirt edge is obtained by the coining/embossing to avoid scratching other cups in post-manufacture operations, and the inwardly angled skirt results in less contact area with the skirts of adjacent mounting cups in handling, shipping, valve assembly, gasketing, etc. following formation of the mounting cups. In addition, the inwardly angled skirt can facilitate retention of cut gaskets when used as the sealant in the mounting cup channel.
Other features and advantages of the present invention will be apparent from the following description, drawings and claims.
Referring to
The aerosol mounting cup 10 of the present invention is made beginning with preferably circular metal disc 15 cut from a metal sheet and having cut edge 15a, as shown in
Preform 16, as made in preform press 20 shown schematically in
Referring now to
In the first embodiment of the method of the invention the essential bumping operation of the present invention is carried out on the skirt edge 13 in the sizing station 24 during the sizing operation as the tooling is closed. More specifically, centering ring/sizing bushing 33 is shown in
When the sizing operation on the mounting cup is carried out as shown on the right side of
Further referring to
It should be appreciated that various alternative tooling set ups may be used to obtain the bumping operation of the present invention.
The present invention also includes a metal mounting cup for an aerosol valve. The cup includes the inner pedestal portion, the outer circular channel portion, and the skirt portion forming the outer wall of the channel portion, the skirt portion having a specified skirt height and a terminating edge, the terminating edge preferably having a minimized unevenness or earring, and the terminating edge being a bumped edge characterized by reformed metal at the terminating edge. The reformed metal will evidence a shiny area at the edge due to the bumping striking the edge high points, and/or a slightly thicker cross-section at the edge where the bumping has occurred.
Following the sizing/bumping station(s) in the transfer press 21 is coax station 25 (see
Referring now to the preferred second embodiment of the method of the invention in which the essential bumping operation is carried out in a reverse or reverse drawing station, for example of a transfer press, reference is made to the reverse/“bumping” station 22′ (that equates to station 22 of
Mounting cup preform 16 is passed to a separate transfer press 21 for further forming operations. Mounting cup preform 16 is received at the first station, which is a reverse or reverse draw/bumping station 22′. As shown in
The essential “bumping” operation of the present invention may be advantageously carried out at a sizing station or at a reverse or reversing station, but also could be carried out at other forming stations, for example, as referred to above, in the press or at a separate dedicated “bumping” station.
The “bumping” operation of the present invention generally may be carried out at any forming station after the preform or cupping operation. The preform or cupping station generally is not suited for the bumping operation since the preform cup skirt is wiped up between two die members that do not allow space for bumping tooling.
The preferred stations for advantageously carrying out the “bumping” operation are the reverse station, the reduction station, and the sizing station. The reverse station is the first station in the transfer press. It receives the preform cup. The “bumping” operation of the invention can advantageously be done in this station with minor modifications and simple tooling employed with reverse tooling. For example, in a free flowing preform cup transfer press that employs a hold down rail to engage the preform skirt edges to hold the preforms on the transfer belt, the rail can be cut away to allow a greater vacuum to hold and transfer the preform cups, and to allow space for simple tooling such as a notched centering ring/bumping ring to enter the cup channel for “bumping” as disclosed herein. Although there are other ways to allow tooling into the channel, this set up has been successfully employed. Effecting the “bumping” operation at the reverse station is advantageous since 1) it allows for the use of simpler tooling than might be required at other stations, 2) it can allow bumped material, if in excess, to flow into the skirt body, 3) it can provide for a better vacuum hold on the preform cup, and 4) any added material or distortion in the body wall can be reworked in a subsequent sizing station.
The “bumping” operation can advantageously be done at the reduction station since it can be done with the same simpler tooling as employed in the reverse station. An advantage of bumping in this station can be that major material movement has already taken place in the reverse station. At this reduction station, because the body side wall is supported when the centering/bumping ring is entering the channel of the preform, the amount of potential distortion is reduced. Also, as in the reverse station, any added material or minor distortion in the body wall can be reworked in the sizing station.
The “bumping” operation can advantageously be done at the reduction station since it is the last major forming station. When the bumping ring comes down to bottom in the channel, while the skirt edge is being “bumped”, the bumping can remove any loose metal and minor distortion resulting from bumping as the inner die parts complete the cup inner profile.
Although less preferred, the “bumping” operation could be carried out at the piercing station. However, this station typically is designed strictly for piercing. No other task typically is performed there. The added task of bumping cannot be done without adding specific tooling for that purpose. Any new press set up can start off with a design to allow a bumping operation. Thus, with a new set up, the advantage would be that the preform cup has completely been formed at the station. The disadvantage would be that if the skirt terminating edge variation were extensive, it could possibly cause distortion of the cup.
Basically the same comments as provided above regarding the piercing station also apply for the less preferred upturn station and the roll over station.
Performing the “bumping” operation at the dimpling station is the least preferred. The tooling that forms the radially outwardly extending dimples or bumps (that protrude from the outer sidewall of the cup body to facilitate control of the cup) operates in the channel of the cup and obstructs the travel path of the center ring and/or bumping ring. This would require specially designed tooling to overcome the dimple tool shortcoming.
Although a coaxing and/or pinching station can be considered a forming station, it would be impractical to carry out these operations during or before the bumping operation. Bumping an already-coaxed or pinched skirt edge could collapse the outer skirt wall or turn it radially inward thereby possibly affecting the overall skirt height, and/or restricting the assembly of a cut gasket into the preform channel. Thus, a coaxing and/or pinching station may follow the sizing/bumping station or the bumping station for further processing of the mounting cup skirt as more fully disclosed in U.S. Pat. No. 6,010,040 of Jan. 4, 2000 titled “Improved Mounting Cup For an Aerosol Container”, the entire contents of which are fully incorporated herein by reference. The coaxing and or pinching operation can be desirably carried out at the last station of the transfer press.
The essential “bumping operation” of the present invention allows a circular disc to be initially used for the preform and eliminates the need for any non-burr trimming operation of the skirt edge after formation of the mounting cup. The “bumping operation” can be carried out after the cupping or preform forming station, at any mounting cup forming station (except in or after the coaxing/pinching station), or in a separate bumping station. The essential “bumping operation” can be advantageously carried out in the transfer press sizing station or, more preferably, in the transfer press reverse or reverse draw station.
It is to be noted that the disclosures that are presented herein relative to carrying out the essential “bumping” operation of the present invention at a sizing station, specifically including and not limited to the disclosures regarding
While the method of the present invention has been described for a single mounting cup, it will be appreciated that many mounting cups are being made at the same time at high speed. Preform press 20 and transfer press 21 include many side-by-side duplicate stations to make the many cups in parallel feed/indexing operations.
It will be appreciated by persons skilled in the art of making aerosol mounting cups that variations and/or modifications may be made to the method of the present invention without departing from the spirit and scope of the invention. The above embodiments are, therefore, to be considered as illustrative and not restrictive.
This application is a continuation-in-part of U.S. application Ser. No. 11/820184, filed Jun. 18, 2007.
Number | Date | Country | |
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Parent | 11820184 | Jun 2007 | US |
Child | 12337326 | US |