Ball Magazine for a Device for Lapping And/Or Grinding Balls

This application claims priority to German patent application no. 10 2024 205 847.5 filed on Jun. 24, 2024, the contents of which are fully incorporated herein by reference.

The present disclosure relates to a ball magazine for a device for lapping and/or grinding balls.

Balls can be used in various applications. Depending on the application, different demands may be placed on geometrical properties and/or surface properties of the balls, such as the roundness of the balls, the surface roughness, the diameter tolerance and/or form errors of the balls, which can be influenced in particular by the processing of the balls.

To process the surface and/or geometry of balls, devices for lapping and/or grinding are known in which balls are processed between two concentric discs. At least one of the discs is provided with at least one ball groove that guides the balls in the device. In general, one of the discs is static whilst the other revolves and thus moves the balls through the at least one ball groove. The movement of the balls and/or of the disc can be utilized to process the surface of the balls. For this purpose, a suitable grinding and/or lapping agent may for example be provided in at least one of the discs and/or in the at least one ball groove.

For economical manufacturing, modern devices for grinding or lapping balls are associated with magazines that accommodate balls in a number several times greater than the number present in a single batch load for the discs. The balls are collected in the magazine after being removed from the lapping or grinding discs, and the balls are fed from the magazine back to the lapping or grinding discs. Examples of known types of magazines are drum-type magazines, bucket elevator-type magazines or ring magazines.

Drum-type magazines however do not provide any separation between lapped and unlapped balls or between balls that have been lapped to a greater or lesser degree, and instead mix these together in an uncontrollable manner. The consequence is that the balls are processed unequally, because only the balls of large diameter are actually lapped, whereas the others are carried along without being processed. The unequal ball diameter however leads to poorly formed channels, which in turn degrades the working result.

The deficiencies of the bucket elevator as a magazine differ from those of a revolving drum only slightly, because the balls are now no longer fed without exception to a common reserve within the magazine but are split up into quantities corresponding to the number of buckets. However, it is also the case here that mixing of balls that have been ground or lapped to a greater or lesser degree is unavoidable.

By contrast, the use of a ring magazine makes it possible for the balls that have undergone the processing operation to perform the entire movement sequence through the lapping or grinding discs and the magazine in series in practically the same sequence. That is to say a ball that has just been processed is fed back to the lapping or grinding discs only after all of the other subsequent balls have passed through the lapping or grinding discs. However, in ring magazines, the balls can become stuck in the ring magazine due to entrained lapping and/or grinding agents, and blockages can thus occur in the ring magazine, which require intervention.

It is therefore an aspect of the present disclosure to provide a ball magazine for a lapping and grinding machine for balls, which ball magazine maintains the sequence of the balls and reduces the risk of the balls becoming stuck in the ball magazine.

A ball magazine for a device for lapping and/or grinding balls will be described below. The ball magazine has a ball removal section that is configured to connect the ball magazine to the device, at least one storage section, and a ball feed section that is configured to guide the balls from the ball magazine back to the device. The storage section may comprise a channel for holding and guiding the balls.

The device for lapping and/or grinding balls may have at least one disc, wherein the at least one disc comprises at least one ball groove for guiding the balls. The balls may be formed in particular from metal, glass, wood, plastics material, ceramic or a combination of these. It is however also possible for the device to have a first and a second disc. In this case, the first disc may be static, and the second disc may rotate relative to the first disc. The discs may preferably be arranged one above the other in the direction of gravitational force, such that the discs are oriented horizontally. The discs may alternatively also be arranged vertically. The first and/or second disc may in particular be designed for grinding and/or lapping the balls.

Furthermore, if the device has two discs, the first disc may have a recess into which the ball removal section and/or the ball feed section is at least partially insertable. The recess may be sector-shaped, rectangular, oval or the like. In particular, the ball removal section may be configured to guide the balls out of the ball groove. The ball feed section may furthermore be configured to guide the balls back into the ball groove.

Furthermore, if the device has two discs, the ball groove may be formed both in the first disc and in the second disc. It is also possible for more than one ball groove, for example two, three, four or even more than four ball grooves, to be provided on the first and/or second disc. It is thus possible for a greater number of balls to be processed simultaneously. If a plurality of ball grooves is provided, these may preferably be arranged concentrically.

Furthermore, if the device has more than one ball groove, a ball-directing means may be provided by which the balls, after passing through a first ball groove, are transferred into the second ball groove, such that the balls pass through all of the ball grooves in succession. The ball magazine may advantageously be coupled to such a ball-directing means. For example, the ball-directing means may be connected to the ball removal section such that the balls, after passing through the final ball groove, are transferred into the ball removal section.

The balls situated between the discs can be set in motion by the rotation of one disc. As the balls roll on the surfaces of the ball groove or of the disc, a more or less pronounced sliding movement, the so-called lapping moment, can occur. The lapping moment, in conjunction with appropriate lapping and/or grinding agents that may be introduced together with the balls into the device, can significantly contribute to a gradual reduction of the out-of-roundness of the balls by material removal and/or to a reduction or even elimination of damage to the ball surface. The removal of the ball material means in particular that a ball diameter at the start of the processing operation is greater than the ball diameter at the end of the processing operation.

To reduce the risk of the balls becoming stuck in the ball magazine, the storage section at least partially has a gradient (is sloped). By means of the gradient, it can be achieved that the balls reach a speed sufficient to reduce the risk of them becoming stuck in the storage section for example due to the presence of entrained lapping and/or grinding agents.

Furthermore, the storage section may also have a region in which the storage section has a flat or planar extent. The storage section may also have a plurality of subsections. For example, subsections having a gradient and subsections that are flat may alternate. This makes it possible to adapt the speeds at which the balls roll in the storage section. Furthermore, the gradient in the storage section may vary or may be constant. For example, the storage section may have at least one subsection having a gradient that differs from the gradient in another subsection of the storage section.

The storage section may have a channel that has a width adapted to the ball diameter. This makes it possible to maintain the sequence of the balls.

The length of the storage section may also be selected to be dependent on a number of balls that are to be accommodated in the storage section. The length of the storage section is preferably selected such that there is a region in the storage section in which the balls can roll freely over a specified distance. This can reduce the risk of an excessive build-up of the balls in the storage section and of the balls becoming backed up as far as the device.

At least one raising unit may preferably be provided between the storage section and the ball feed section, the at least one raising unit being configured to raise at least one ball and guide the ball to the ball feed section. Since the ball magazine has a gradient, an end of the storage section is lower than a start of the storage section, and it may be necessary to raise the balls to a level from which the balls can be guided back to the device. This can advantageously be achieved by means of the raising unit. For example, the at least one raising unit may be arranged at a lowest point of the storage section. The at least one raising unit may preferably comprise a conveying screw or a conveyor belt.

The ball removal section may also have a gradient that brings the balls to a height level that lies above a height level of the device. To ensure that the balls do not become stuck in the storage section, it is necessary for the storage section to have a minimum gradient. That is to say, a length of the storage section and thus also the maximum number of balls that can be stored in the storage section is also dependent on the maximum available starting height level for the start of the storage section. Since the ball removal section additionally has a gradient, the starting height level of the storage section can be raised, and thus the possible storage capacity of the storage section can be increased.

Furthermore, the ball removal section, the storage section and/or the ball feed section may have at least one ball-guiding element. The ball-guiding element may be configured to prevent the balls from falling out. The ball-guiding element may advantageously be configured to have a very low friction resistance in order to reduce the risk of the balls becoming stuck in the ball-guiding element. The ball-guiding element may for example be a channel, a rail, one or more rods, or the like. In particular, the ball-guiding element may be configured to support the balls counter to gravitational force.

Preferably, the ball removal section, the storage section and/or the ball feed section may have at least one guide element for a spacer, which is configured to space two balls apart from one another. The guide element can advantageously ensure that the spacer is not lost in the ball magazine, and the balls abut against one another. For example, the spacer may be designed as a ring arranged around a ball, and the guide element may have a U-shaped profile in which the spacer can be guided.

Furthermore, at least one securing element may be provided, which secures the balls against falling out. The securing element may preferably be provided depending on a gradient of the ball removal section, of the storage section and/or of the ball feed section. For example, if the ball removal section, the storage section and/or the ball feed section is formed as a type of channel, the balls may fall out of the channel if a gradient of the section in question is too steep. The securing element may then for example be arranged above the channel such that the balls cannot fall out of the channel.

A thread flight of the conveying screw may preferably be dependent on a ball diameter. For example, a height of the thread flight may be adapted such that a ball can be received in a thread flight of the conveying screw. This allows the balls to be conveyed smoothly by the raising unit.

Furthermore, the at least one raising unit may interact with a spacer, which is configured to space two balls apart from one another, in order to raise the balls. For example, the spacer may be configured as a ring arranged around a ball, and the raising unit may be configured to raise the spacer and thus concomitantly raise the ball arranged in the spacer.

An alignment section may preferably be provided, which is configured to align the spacer with a conveying axis of the raising unit. This has the advantage that the raising unit can raise the ball together with the spacer. This can also reduce the risk of the spacer falling off the ball as the ball is being raised by the raising unit.

The ball magazine may furthermore have a plurality of raising units and/or storage sections. This can make it possible to increase the storage capacity of the ball magazine. In particular, the storage sections and raising units may be arranged in alternation, such that each storage section is followed by a raising unit.

According to a further aspect, an arrangement for lapping and/or grinding balls is provided, wherein the arrangement comprises at least one first device for lapping and/or grinding balls and one second device for lapping and/or grinding balls and at least one ball magazine described above, wherein the at least one ball magazine is arranged between the first and the second device such that the ball removal section of the ball magazine removes the balls from the first device and the ball feed section guides the balls from the ball magazine to the second device.

Further advantages and advantageous embodiments are specified in the description, in the drawings and in the claims. In particular, the combinations of features specified in the description and in the drawings are merely examples, and therefore the features may also be present individually or in other combinations.

The disclosure will be described in more detail below on the basis of exemplary embodiments that are illustrated in the drawings. The exemplary embodiments and the combinations shown in the exemplary embodiments are merely examples and are not intended to specify the scope of protection of the disclosure. The scope of protection is defined solely by the appended claims. Below, identical or functionally equivalent elements are denoted by the same reference signs.

A ball magazinefor a devicefor lapping and/or grinding ballsaccording to a first embodiment will be described with reference to. The devicefor lapping and/or grinding ballshas a first discand a second discwhich include at least one ball groovefor guiding the balls. The deviceshown inhas three ball grooves. It is however also possible for the deviceto have a greater or smaller number of ball grooves.

In particular, the first discmay be static, and the second discmay rotate relative to the first disc. As can be seen in, the discs,may be arranged one above the other in the direction of gravitational force, such that the discs,are oriented horizontally.

The ballssituated between the first and second discs,can be set in motion by the rotation of the one disc. As the ballsroll on the surfaces of the ball groove or of the disc, a more or less pronounced sliding movement, the so-called lapping moment, can occur. The lapping moment, in conjunction with appropriate lapping and/or grinding agents that may be introduced together with the ballsinto the device, can significantly contribute to a gradual reduction of the out-of-roundness of the ballsby material removal and/or to a reduction or even elimination of damage to the ball surface. The removal of the ball material means in particular that a ball diameter at the start of the processing operation is greater than the ball diameter at the end of the processing operation.

The ball magazinefurthermore comprises a ball removal sectionthat is configured to connect the ball magazineto the deviceand to remove the balls from the device. From the ball removal section, the ballsare guided onward to a storage section, in which the ballscan be stored. The storage sectionguides the ballsto a ball feed sectionthat is configured to guide the ballsfrom the ball magazineback to the device. The storage section may comprise a channel.

To reduce the risk of the ballsbecoming stuck in the ball magazine, at least part of the storage sectionhas a slope or a gradient. By means of the gradient, it can be achieved that the balls reach a speed sufficient to reduce the risk of them becoming stuck in the storage sectionfor example due to the presence of entrained lapping and/or grinding agents.

Furthermore, the ball removal section, the storage sectionand the ball feed sectioneach have a channelthat has a width adapted to the ball diameter. The channelmay be designed as a ball-guiding element that guides the balls. The channelmay for example have a plurality of parallel rodsthat guide the balls. For example, the channelmay be formed by at least one rodarranged under the ballsand two rodsarranged laterally adjacent to the balls. The channelmay alternatively also be of some other form. For example, the channelmay also be in the form of a half-shell. Depending on a gradient, a securing element (not illustrated) may be provided, which secures the balls against falling out of the channel. The securing element may then for example be arranged above the channelsuch that the ballscannot fall out of the channel.

Furthermore, the ball removal section, the storage sectionand/or the ball feed sectionmay have at least one guide elementfor a spacer, which is configured to space two ballsapart from one another. In, the spaceris formed as a ring arranged around a ball, and the guide elementis a U-shaped profile that partially surrounds the spacer.

As can be seen in, the storage sectionhas a plurality of subsections,,,. The subsections,,,may have different gradients. For example, one or more subsections,,,may at least partially have a flat extent. Furthermore, the gradient in the subsections,,,may vary or may be constant.

The length of the storage sectionmay also be dependent on a number of ballsthat are to be accommodated in the storage section. The length of the storage sectionis preferably selected such that there is a region in the storage sectionin which the ballscan roll freely over a specified distance.

The discmay furthermore have a recess into which the ball removal sectionand the ball feed sectionare partially inserted. The recessmay be sector-shaped, rectangular, oval or the like. Since the illustrated devicehas more than one ball groove, a ball-directing means (without reference sign) is provided by which the balls, after passing through a first ball groove, are transferred into the second ball groove, such that the ballspass through all of the ball grooves in succession. The ball magazinemay advantageously be coupled to such a ball-directing means. For example, the ball-directing means may be connected to the ball removal sectionand to the ball feed sectionsuch that the balls, after passing through the final ball groove, are transferred into the ball removal sectionand, after passing through the ball magazine, are introduced from the ball feed sectioninto the first ball groove.

In order, at the end of the storage section, to raise the ballsback to the level of the device, a raising unit, sometimes referred to as an elevator, is provided between the storage sectionand the ball feed section. In the ball magazineaccording to the first embodiment, the raising unitis designed as a conveying screw. Here, a height of a thread flightof the raising unitis adapted to a diameter of the spacer. Here, the ballis situated together with the spacersuch that the spacerlies at least against one thread flank. To orient the spacersuch that the spaceris in contact with the thread flank, an alignment sectionis provided upstream of the raising unit, which alignment section, with the aid of the guide element, aligns the spacerwith a conveying axis of the conveying screw. If no spaceris provided, the height of a thread flightmay be adapted to a ball diameter.

A ball magazinefor a devicefor lapping and/or grinding ballsaccording to a second embodiment will be described with reference to. The ball magazineaccording to the second embodiment differs from the ball magazineof the first embodiment in that the ball removal sectionhas a gradient (slope)that brings the ballsto a height level that lies above a height level of the device.

A raising unitfor a ball magazineaccording to a third embodiment will be described with reference to. The raising unitof the ball magazineaccording to the third embodiment differs from the raising unitof the ball magazinein the first embodiment in that the raising unitcomprises a conveyor belt. To orient the spacersuch that the spacerdoes not come into contact with the conveyor beltin front of the ball, an alignment sectionis again provided upstream of the raising unit, which alignment section, with the aid of the guide element, aligns the spacerwith a conveying axis of the conveyor belt.

Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved ball magazine for a device for lapping and/or grinding balls.

Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.