Patent Application
20190300213
The present invention relates to tooling for use in the canning of items such as fruits and vegetables and more particularly to tooling having improved lifespan and reliability.
Containers such as metal cans have been used for containing and storing items such as food products. When such cans are used to store food, various design requirements come into play, such as the use of food safe materials in the cans themselves and in the processing and tooling used to construct the cans.
The construction of such cans often involves the attachment of a lid to a previously formed cylindrical can body. The lid can be attached by a double seaming process wherein the lid and can body are tightly sealed to assure a strong airtight seal between the lid and can body. The lid edge and can body can be formed with a predetermined curved edge. The lid and can body are then processed by a first set of chucks and first set of rollers that curls edge of the lid over the edge of the can body. Then, the lid and can body can be pressed between a second set of chucks and a second set of rollers that squeeze the curled edges together to form a tight, secure seal between the lid and can body.
Tooling such has “P” model seaming machines produced by ANGELUS® has been used for some time, and machines such as these play a major role in the processing of tomato crops. Such tooling can be configured as three station (aka “three head”) seaming machines. The seamers typically close 60 to 100 cans per minute, depending on the size of the steam cookers used in the process.
The canning of certain food products presents even more specialized challenges. For example, when canning tomato products, the acidity of the canning environment causes quick corrosion of tooling used to seal the cans. In addition, the canning of tomato crops necessarily happens over a very short season of roughly three months. Therefore, there is a need to reduce the amount of down time and maximize speed of processing when canning such tomato products.
The present invention provides a tool for seaming cans. The tool includes a pin structure, a portion of which defines a spindle. A seam roll is rotatably mounted on the spindle, with the seam roll and pin structure defining a gap between them. The tooling further includes one or more O-rings disposed within the gap between the seam roll and the pin structure.
The O-rings are placed advantageously to semi seal the gap between the pin structure and the seam roll so as to prevent corrosive environmental contaminates from entering the interior of the tooling and corroding or otherwise damaging interior components as well as to provide an escape to allow lubricant to be periodically added. This greatly increases the life of the tooling and prevents costly downtime in the canning process.
The tooling can also include one or more bearing assemblies located between the pin structure and the seam roll to facilitate the rotation of the seam roll on the spindle. The use of the above described O-rings prevents corrosive materials from entering the tooling and corroding the bearing assemblies. The bearing assembly can be a food-safe stainless-steel bearing. Or, for even further improved corrosion prevention, the bearing assembly can be one or more ceramic bearing assemblies, such as bearing assemblies that incorporate the use of ceramic balls enclosed in a housing. The invention can include a protective O-ring located at either end of the seam roll, and can include two O-rings fitted into a groove at one end of the seam roll.
The tooling assembly can be held together by a novel self-locking screw. The self-locking screw can include a head portion and a threaded shaft portion with a recess formed in the side of the threaded shaft portion. A polymer ball, such as a nylon ball can be fitted into the recess formed in the side of the threaded shaft portion of the screw. In use, the polymer ball engages the adjacent threads of the bore into which it is inserted, thereby preventing the screw from inadvertently coming loose. In use, the screw can be inserted and removed many times with the polymer ball remaining intact and providing effective protection against loosening of the screw. However, if the ball does eventually wear out, the ball can simply be removed from the screw and replaced at negligible time and expense. The screw can also be formed with an internal bore, which can extend through the screw and which can facilitate greasing of the tooling assembly without the need for disassembling the tooling.
These and other features and advantages of the invention will become apparent upon reading of the following detailed description of the embodiments taken in conjunction with the figures in which consistent reference numbering is used to indicate similar elements throughout.
For a fuller understanding of the nature and advantages of this invention, as well as to illustrate the preferred mode of use, reference should be made to the following detailed description, read in conjunction with the accompanying drawings, which for clarity are not drawn to scale.
The following description is of the best embodiments presently contemplated for carrying out this invention. This description is made for the purpose of illustrating the general principles of this invention and is not meant to limit the inventive concepts claimed herein.
A can lid may be securely attached to a can body by a multi-stage seam rolling operation, such as that illustrated with reference to
The tooling 100 can include a first set of seam rollers 110 that are formed with a first groove 112 and which is rotatably connected with a shaft 114, and a second set of seam rollers 116 having a second groove 118 and which are rotatably connected with a shaft 120. In a first seaming operation, the seaming chuck 108 is rotated about the axis 105 of the can body 104, while engaging the first seam roller 110 against the outer edge of the can end 102 as shown in
One challenge that arises with the canning of certain food products is that of corrosion to canning tooling. This is especially problematic when canning acidic foods such as tomatoes. In addition, all products and tooling used in the canning process must be food-safe materials. This includes lubricants such as grease used to lubricate and protect the can seaming tooling during the seaming operation. In addition, many products such as produce products must be canned in a short window of time when the canned products are in season. For example, an entire year's tomato crop must be canned in a timeframe of about three months. This means that any downtime resulting from damaged or corroded tooling can lead to greatly increased cost and possibly crop spoilage. The present invention, embodiments of which are described below, prevents such corrosion or damage to tooling, even in highly corrosive, acidic environments while also maintaining food-safe standards.
In addition to the roller bearing 610, the seam roller assembly 602 can include a pair of thrust bearings 614 to facilitate the spinning movement of the seaming roll 608, while holding the seaming roll 608 in the direction along the axis of the shaft 607. Thrust washers 616 can be provided adjacent to the thrust bearings 614 either on one side or both sides of each thrust bearing 614. For example, as shown in
Can seaming tooling is often used in corrosive environments. For example, the canning of acidic food products such as tomatoes results in a highly corrosive environment which can greatly reduce the lifespan of various components of a seam roller assembly, especially with regard to the roller bearing 610 and thrust bearings 614. In order to protect these components from corrosion, the seam roller assembly can be periodically injected with a food safe grease through an injection port, not shown. In previous seam roller tooling, this grease would quickly leak out, such as between the roller 608 and main pin 604, allowing corrosive external materials to enter into the seam roller assembly 602 and also requiring frequent re-application of grease. Both of which lead to increased downtime and decreased tooling lifespan.
The present invention, such as shown in the embodiment illustrated in
Because the seam roll 608 is designed to spin on the main pin 604, it would not be intuitive to use O-rings in the fashion illustrated and described with reference to
The gap 624 located at the outer diameter of the seam roller 608 and main pin 604 is the entrance point that is most susceptible to the entrance of corrosive environmental contaminants. Therefore, as shown in
With continued reference to
The use of O-rings 620, 622 in can seam rolling tooling as described above has never before been contemplated or used in the can seaming industry. This improvement in the design of a can rolling assembly tool 602 greatly increases the life of the tool during use. In addition, this design greatly reduces process down-time which would otherwise be necessary to replace the seam rolling tool, replace bearings within the seam rolling tool or to re-grease the tool. The use of such a design has been shown to provide on the order of a 20-fold increase in uninterrupted operation time. In addition, this improvement can be realized with minimal additional manufacturing cost.
The assembly 802 also includes a seam roll 812 that is configured to spin about the spindle 808 of the main pin 804. First and second bearing assemblies 814, 816 are disposed about the spindle 808 (between the spindle 808 and seam roll 812) to facilitate the spinning of the seam roll 812 about the spindle 808. In this embodiment, the bearing assemblies 814, 816 are preferably ceramic bearing assemblies that each can include a ceramic ball 818 held within a casing 820. The use of ceramic bearings in the assembly 802 further prevents damage to the bearings 814, 816 from use in a corrosive environment. The ceramic materials are essentially inert and not susceptible to corrosion such as from an acidic environment.
A bearing spacer 822 in the shape of a washer can be inserted between the bearing assemblies 814, 816 to maintain a desired spacing between the bearing assemblies 814, 816. A screw 824, screws into a threaded opening in the spindle 808 of the main pin 804. The screw is preferably a flat head socket cap screw having an interior bore that extends through the screw 824. A contoured washer 826 is disposed between the screw 824 and bearing assembly 816. As can be seen, the screw 824 presses the bearing assemblies 814, 816 against the flange 810 of the main pin 804, thereby securely holding the bearing assemblies 814, 816 within the assembly 802. A snap ring 828 fits into a space between the securely held bearing assemblies 814, 816 and into a slot in the inner diameter of the seam roll 812. This effectively holds the seam roll 812 in place, preventing movement of the seam roll 812 in a direction parallel with the axis of the spindle 808. Movement of the seam roll 812 in a lateral direction (perpendicular to the axis of the spindle 808) is limited by engagement with the outer portion of the bearing assemblies 814, 816, while also allowing the seam roll 812 to spin freely about the spindle 808.
A bottom cap 830 fits into the end of the seam roll 812, and is securely held in place by a spiral retaining ring 832. In
With continued reference to
As with the previously described embodiment, the O-rings 836, 838 are sufficiently thin and flexible to allow air and grease to escape past them when under pressure such as during the previously described grease packing operation. However, the O-rings 836, 838 are also sufficiently thick and firm to prevent grease from passing through them when not under significant pressure during operation and also to prevent contaminates, from entering the assembly 802 during operation.
The flange 810 of the main pin 804 has an outer portion that wraps around an outer diameter of the seam roll 812 to form a gap between the seam roll 812 and flange 810 at least a portion of the gap being oriented parallel with the axis of the spindle 808. As with the previously described embodiment, the O-rings 836 can be located in this parallel gap portion. This portion of the flange 810 can be formed with a groove into which the O-rings 836 securely sit. At the other end, the bottom cap 830 can be formed with a bent tab at its outer end that also defines a gap between the cap 830 and seam roll 812 that is oriented substantially parallel with the axis of the spindle 808. The seam roll 812 can be formed with a groove at its inner circumference in which the O-ring 838 can securely sit.
With reference to
A seam roller 1012 is configured to fit over the spindle 1006. The seam roller 1012 has an outer profile that is configured to a desired shaping function to deform can and lid ends in a desired manner such as described above with reference to
The seam roller 1012 rides on a roller bearing 1014 which fits between the spindle 1006 of the main pin 1002 and the inner bore of the seam roller 1012. The roller bearing 1014 advantageously is constructed of stainless-steel components, such as stainless-steel rollers 1016. Stainless steel components have not previously been used in canning tooling, because of the added cost and manufacturing complexity. Stainless-steel is a hard metal and, therefore, difficult to machine. In addition, the use of stainless-steel components increases manufacturing cost, because of the added cost of the metal itself. However, the inventors have found that the use of stainless-steel bearing components, surprising, decreases cost in the long run due to the greatly increased lifespan of the product and greatly reduced need for frequent maintenance of the tooling. As previously discussed, canning tooling is often operated in harsh corrosive and messy environments. Environmental contaminants such as acidic tomato and other fruit juices quickly corrode the components of the canning tooling. In order to prevent this, prior art tooling must be frequently maintained, such as by re-greasing the tooling, and by costly replacement of damaged and/or corroded parts. This results in expensive manufacturing down time, which is very disruptive, and increases processing cost. Even in spite of this frequent re-greasing, the internal components of prior art tooling corrode and fail, leading to further increased cost in the long run. The inventors have found that, by using stainless steel bearing components (e.g. stainless-steel roller bearing 1014), the increased cost of the stainless-steel components is more than offset by the long life and low required maintenance and down-time of the tooling.
With continued reference to
The seam roller 1012, bearings 1016, 1018 and washer 1020 are held in place over the spindle 1006 by a bottom cap 1022 and self-locking screw 1024. The screw 1024, which will be described in greater detail herein below, is configured to thread into a threaded interior bore 1028 of the main pin 1002. The cap 1022 is configured to engage the outer end of the seam roller 1012.
When, the tooling 1000 is assembled, as shown in
With reference to
In addition, in another possible embodiment the screw can be formed as a pilot screw 1036 to facilitate manual engagement into the tooling 1000. The pilot screw 1036 has a reduced diameter portion 1038 at the end of the threaded portion of the screw 1036. This allows an operator to easily insert the screw 1036 into the tooling 1000 by hand prior to tightening.
First and second bearing assemblies 1210 are configured to fit over the spindle 1208. The bearing assemblies are preferably ball bearing assemblies that are configured withstand a thrust load in a direction that is parallel with the longitudinal axis of the spindle 1208. The bearing assemblies can include ceramic balls 1302 (
A seeming roll 1212 fits over the bearing assemblies 1210 so as to spin freely about the spindle 1208. A bearing spacer 1214 in the form of a washer is disposed between the bearing assemblies 1210 to maintain a desired separation between the bearing assemblies 1210 at their inner diameters. In addition, a snap ring 1216 is located between the bearing assemblies at their outer diameter. As can be seen in
A screw 1218 is configured to screw into a threaded interior bore of the main pin 1202. The screw 1218 can be a self-locking, flat head, socket screw, and can be configured with an internal bore that extends through the screw 1218. The screw 1218 holds the bearing assemblies 1210 securely on the spindle 1208 by holding the bearing assemblies 1210 against the flange 1206 of the main pin. A formed spacer 1220 can be provided between the screw 1218 and the nearest bearing assembly 1210. Because the longitudinal movement of the seaming roll 1212 relative to the bearings 1210 is prevented by the snap ring 1216, the seaming roll 1212 remains securely held on the main pin 1202 while being free to rotate.
A bottom cap 1222 is formed to cover the end of the seaming roll 1210. As can be seen, in this embodiment, the screw 1218 is inside the assembly relative to the cap. The cap 1222 can be formed to snap fit into the end of the seaming roll and can be further held in place by a spiral retaining ring 1224 which fits into a groove in the inner diameter of the outer end of the seaming roll 1210. An optional “O” ring 1226 can be located between the cap 1222 and the seaming roll to seal the space between the cap 1222 and the seaming roll 1210.
In order to lubricate the assembly 1200, grease can be injected under pressure into the bore within the end 1204 of the main pin 1202 as indicated by arrow 1306. In
As can be seen in
With reference to
When in use, the ball 1408 provides a pliable consistent friction against a threaded opening into which the screw 1402 is fastened. This friction between the ball 1408 and the adjacent threads of the opening (not shown) into which the screw is inserted ensures that the screw will remain securely engaged within the opening. Testing has shown that the screw 1402 can be used for many cycles with a single ball 1408. That is, the screw 1002 can be screwed into a threaded opening, removed, and reinserted many times with the ball 1008 remaining intact and securely holding the screw in place. However, if at some time the ball 1408 becomes worn and ineffective, it can easily and inexpensively be removed and replaced with a new polymer (e.g. nylon) ball 1408, at which time that screw 1402 can continue use for many more applications. A self-locking screw 1402 such as that described provides an extremely cost effective solution compared with other previously used locking screw devices. The screw not only provides a self-locking feature at greatly reduced expense, but also provides the additional benefit of being able to be used for many fastening cycles and provides the added advantage that the polymer ball 1408 can be replaced after many cycles of use.
In addition, the screw has a novel head 1406, which can be understood more clearly with reference to
The screw 1402 can also be configured with a pilot end 1412 as shown in
While various embodiments have been described above, it should be understood that they have been presented by way of example only and not limitation. Other embodiments falling within the scope of the invention may also become apparent to those skilled in the art. Thus, the breadth and scope of the invention may also become apparent to those skilled in the art. Thus, the breadth and scope of the inventions should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
| Number | Date | Country | |
|---|---|---|---|
| 62651608 | Apr 2018 | US |
