NL2035311B1

NL2035311B1 - Assembly for a bellow and bellow

Info

Publication number: NL2035311B1
Application number: NL2035311A
Authority: NL
Inventors: Faizal Van Drunen Jaïr; Antonius Van Loon Wouter
Original assignee: Waltr B V
Priority date: 2023-07-07
Filing date: 2023-07-07
Publication date: 2025-01-14
Also published as: WO2025012007A1

Abstract

An assembly for a bellow comprising a helical push spring; and a spring holding device, the spring holding device comprising a ﬁrst part, and a second part connectable to the first part to form a cylindrical shell, wherein an outer circumferential surface of the cylindrical shell is provided with a groove for accommodating the helical push spring, wherein the groove wraps around the outer circumferential surface of the cylindrical shell with a pitch corresponding to a pitch of the helical push spring, such that, when the first part is connected to the second part, the spring holding device is screwable into the helical spring, as well as a bellow, comprising such an assembly, a cover for covering the helical push spring, and a clamp for clamping the cover to the outer surface of the first spring holding device are disclosed.

Description

Assembly for a bellow and bellow

Field of the invention

[0001] This disclosure relates to an assembly for a bellow and to a bellow.

Background art

[0002] Bellows can be used to protect various machine parts. For example, a bellow may be used to protect cables and/or movable parts, such as hinges, cylinders, spindles, and/or other rotatable parts.

[0003] A bellow may comprise a spring and a cover for covering the spring. The bellow may be arranged around a machine part, so that the cover protects the machine part.

[0004] Putting the bellow around the machine part may allow for protecting the machine part from the surroundings of the machine part. For example, such an arrangement of the bellow may prevent dirt or dust from entering the machine part. As an alternative or additional example, the bellow may prevent grease or oil from the machine part from contaminating the surroundings. As an alternative or additional example, when used for protecting a machine part of a machine in the food industry, the bellow may protect the machine from being contaminated, as well as protect the machine from causing contamination. This enables hygienic operation and may contribute to food safety. So, it is desirable to protect machine parts using bellows.

[0005] Examples of bellows are described in US2019016187A1, GB2478906A, and

DE102011109895.

[0006] The above description is not necessarily prior art publicly known before the present application was filed.

Summary of the invention Technical problem

[0007] Although it is desirable to protect machine parts using bellows, this is not always convenient. For example, in order to mount a bellow on the machine part, it may be required to take the machine, or a portion thereof apart, which is be time-consuming and costly. Furthermore, space inside a machine may be constrained. The radius of certain bellow designs expands when the bellow is compressed. Inside some machines, there may not be room for such an expansion. Either or both of these problems tend to be relatively prevalent when it is desired to mount a bellow on a longitudinal machine part of a small diameter, for example, when a diameter of the machine part is between 1 cm and 10 cm.

[0008] So, there is a need for a bellow that may be mounted on a machine part without requiring the machine to be taken apart. Additionally or alternatively, there is a need for abellow that does not substantially increase in radius when compressed in a longitudinal direction. Either or both of these needs may particularly, but not necessarily exclusively, arise when it is desired to mount a bellow on a longitudinal machine part of a small diameter. Furthermore, the skilled person will appreciate that various features of embodiments of this disclosure may have additional or alternative effects.

Technical solution

[0009] In a first aspect of the invention. an assembly for a bellow is provided. The assembly comprises a helical push spring and a first spring holding device. The spring holding device comprises a first part, and a second part connectable to the first part to form a cylindrical shell, wherein an outer circumferential surface of the cylindrical shell is provided with a groove for accommodating the helical push spring, wherein the groove wraps around the outer circumferential surface of the cylindrical shell with a pitch corresponding to a pitch of the helical push spring, such that, when the first part is connected to the second part, the first spring holding device is screwable into the helical spring.

[0010] The assembly according to the first aspect allows for convenient mounting of a bellow on a machine part. The helical push spring can be placed around the machine part.

The first part and the second part are connectable, so can also be taken apart. When the first part and second part are connected, the spring holding device can be screwed into the helical push spring, because the outer circumferential surface of the spring holding device is provided with a groove therefor. Starting from a disassembled state, in which the first part and the second part are disconnected, the helical push spring can be rotated over the machine part, so that the machine part is surrounded by the helical push spring.

Then, the first part and the second part can be ot together, while located at an end of the machine part not covered by the helical push spring, such that the machine part is inside the cylindrical shell. Then, the spring holding device can be screwed into the helical push spring. After screwing the spring holding device into the helical push spring, the helical push spring secures the first and second part together. Other parts of the bellow may subsequently be attached. In this way, a bellow can be mounted to a machine part without needing to take the machine apart. Both during and after the mounting, the amount of space needed is limited. Because a helical push spring is used, when the bellow is compressed, the helical push spring is compressed. This compression of the helical push spring allows for the bellow to be compressed without substantial expansion in radius.

So, an assembly according to the first aspect allows for a particularly convenient way of mounting a bellow, that may be suitable for machine parts with a small diameter.

[0011] Advantageously, the first part and the second part are of semi cylindrical shell shape. When the two parts are connected, they should form a cylindrical shell. Having both parts of semi cylindrical shell shape allows for the two parts to form such a cylindrical shell. Furthermore, two semi cylindrical shells are convenient to mount around a longitudinal machine part.

[0012] Advantageously, the first part and the second part are mechanically connectable.

For example, the first part and the second part may be connectable through pins and matching holes, wherein the pins are oriented substantially perpendicular to the cylinder axis of the cylindrical shell. For another example, the first part and the second part may be connectable through dovetail joints. By providing a mechanical connection between the two parts, after assembly, the bellow may be more solid. In particular, by mechanically connecting the two parts in addition to the spring securing the two parts together, a risk of the bellow falling apart during operation may be further mitigated compared to not providing a mechanical connection. Because, in typical operation, the bellow primarily moves in the longitudinal direction, the mechanical connection should preferably particularly prevent the two parts from disconnecting due to forces in the longitudinal direction.

[0013] Advantageously, the first spring holding device comprises a handle. A handle allows the spring holding device to be screwed in conveniently.

[0014] Advantageously, a depth of the groove corresponds to a thread diameter of the helical spring. In this case, after the spring holding device is screwed into the helical push spring, the helical push spring is fully accommodated in the groove. This means that the surface of the helical push spring together with spring holding device is even. Such an even surface allows for a cover to be attached tightly to form the bellow. This may allow tor a bellow that is dust proof or water proof.

[0015] Advantageously, an inner diameter of the cylindrical shell is at most 40 mm, preferably at most 30 mm, more preferably at most 20 mm, most preferably at most 10 mm. The spring holding device is particularly suitable for forming bellows around machine parts with small diameters.

[0016] In a second aspect of the invention, a bellow is provided. The bellow comprises an assembly according to the first aspect, a cover for covering the helical push spring, and a clamp for clamping the cover to the outer surface of the first spring holding device.

[0017] A bellow according to the second aspect can be mounted to a machine part without needing to take the machine apart. Both during and after the mounting, the amount of space needed is limited. Because a helical push spring is used, when the bellow is compressed, the spring is compressed. This compression of the spring allows for the bellow to be compressed without substantial expansion in radius. So, a bellow according to the second aspect may be mounted particularly conveniently, and/or may be suitable for machine parts with a small diameter.

[0018] Advantageously, the helical push spring comprises a first end and the first spring holding device is screwed into the helical push spring proximal to the first end. In this way, the first spring holding device forms an end piece of the bellow. The cover may then be clamped to this end piece.

[0019] Advantageously, the bellow further comprises a second spring holding device according to the first aspect, wherein the helical push spring comprises a second end and the second spring holding device is screwed into the helical push spring proximal to the second end. This enables a bellow with two end pieces according to the first aspect. The cover can then be conveniently clamped to both ends of the bellow. It is additionally or alternatively possible to provide one or more additional spring holding devices along one or more intermediate locations along the bellow. Optionally, the cover can then be clamped to some or all of the one or more additional spring holding devices. The first, second, and/or additional spring holding devices may optionally be substantially identical and/or substantially mirroring each other.

[0020] Advantageously, the cover is removable from the helical push spring. For example, the cover may comprise a zip. A removable cover may be conveniently mounted and/or dismounted. This can be advantageous both for mounting and/or dismounting the bellow as a whole and for replacing the cover. Replacing the cover may be convenient, because it can allow for cleaning the replaced cover when it is not on the bellow. The machine can then continue functioning with the replacement cover.

Furthermore, if the cover 1s damaged, it can be quickly and conveniently replaced without needing to replace the entire bellow. To provide a removable cover, a cover comprising a zip may be used. A zip may be positioned so that it curves around the bellow when the cover is mounted on the bellow. In this way, tension is spread out. Of course, a removable cover may also be provided in various alternative or additional ways. For example, the removable cover may comprise one or more of a Velcro strip, buttons, hooks and eyes, and/or sticky tape.

[0021] Advantageously, the cover comprises at least one of a fire-retardant material, a heat-resistant material, a material suitable for use in the food industry, and/or an airtight material. Depending on the intended application of the bellow, many kinds of suitable material may be chosen for the cover.

[0022] Advantageously, the clamp is a band clamp. For example, the clamp may be a worm drive hose clamp. The clamp is for clamping the cover to the bellow. In particular, the cover is clamped to the spring holding device. The skilled person appreciates that, for the band clamp to function, a substantially even surface with the width of the band clamp is desirable. Furthermore, the surface to which the cover is clamped should preferably not vary in shape during operation. So, clamping the cover to the spring holding device is more convenient than clamping the cover to the spring.

[0023] In a third aspect of the invention, a machine part is provided. The machine part is provided with a bellow according to the second aspect, wherein the machine part has a substantially longitudinal shape and a main axis of the substantially longitudinal shape coincides with a main axis of the bellow.

[0024] The bellow according to the second aspect can be mounted to the machine part according to the third aspect without needing to take the machine apart. Both during and after the mounting, the amount of space needed is limited. Because a spring is used, when the bellow is compressed, the spring is compressed. This compression of the spring allows for the bellow to be compressed without substantial expansion in radius. So, a spring holding device according to the first aspect allows for a particularly convenient way of mounting a bellow, that may be suitable for machine parts with a small diameter.

[0025] Advantageously, the machine part comprises a hinge, a cylinder, a spindle, a cable, or a rotatable part. These kinds of machine parts are longitudinal and may need to be protected with a bellow.

[0026] In a fourth aspect of the invention, a machine comprising a machine part according to the third aspect is provided. Because the bellow may be mounted relatively quickly and conveniently, the down time of the machine when mounting the bellow may be limited.

[0027] In a fifth aspect of the invention, a method of protecting a machine part using a bellow according to the second aspect is provided. The method comprises rotating the helical push spring over the machine part, connecting the first part and the second part of the first spring holding device, such that the machine part is in an inside of the cylindrical shell, screwing the first spring holding device into the helical push spring, and clamping the cover to the outer surface of the first spring holding device.

[0028] The method according to the fifth aspect allows for a bellow to be mounted to a machine part.

Brief description of drawings

[0029] Embodiments of the present invention will be described hereinafter, by way of example only, with reference to the accompanying drawings which are schematic in nature and therefore not necessarily drawn to scale. Furthermore, like reference signs in the drawings relate to like elements and a repeated description related thereto may be omitted. In the attached figures, - Figure 1 schematically shows a spring holding device, - Figure 2 schematically shows a bellow, - Figure 3 schematically shows a partially assembled bellow, - Figure 4 schematically shows an end of a bellow, - Figure 5 schematically shows a method of protecting a machine part using a bellow - Figures 6A-6C schematically show a compressed bellow, and - Figures 7A and 7B schematically show various components of a bellow.

Detailed description

[0030] Figure 1 schematically shows a spring holding device 1.

[0031] The spring holding device 1 is adapted to hold a spring, such that a bellow may be formed. The spring holding device 1 comprises a first part 11, a second part 12, and a groove 13. The first part 11 and the second part 12 are connectable. When the first part 11 is connected to the second part 12, a cylindrical shell is formed.

[0032] Figure 1 schematically shows that both the first part 11 and the second part 12 are of semi-cylindrical shell shape. In this way, when the first part 11 and the second part 12 are connected, a cylindrical shell is formed. In order to form the cylindrical shell, it is convenient to use two semi-cylindrical shells, because each of these two semi-cylindrical shells can easily be placed on one side of a substantially cylindrical machine part in order to accommodate the substantially cylindrical machine part into the inner cylinder of the formed cylindrical shell without needing to move the substantially cylindrical machine part.

[0033] However, alternative shapes of the first part 11 and second part 12 are possible.

For example, either of these may comprise more than half of the cylindrical shell, while the other comprises less than half, so that together, the two parts still form the cylindrical shell. Furthermore, it is possible to have more than two parts forming the cylindrical shell. For example, the cylindrical shell may be formed out of three, four, or more parts.

However, when at least one part comprises more than half of the cylindrical shell and/or when there are three or more parts, it may be more complicated to connect the various parts to each other in order to form the cylindrical shell. Therefore, an embodiment in which both the first part 11 and the second part 12 are of semi-cylindrical shape is preferred.

[0034] The cylindrical shell that is formed when the parts are connected together may accommodate the machine part. The spring holding device 1 is particularly suitable for forming a bellow around a machine part with a relatively small diameter. For example, the inner diameter of the cylindrical shell may be at most 40 mm, preferably at most 30 mm, more preferably at most 20 mm, most preferably at most 10 mm.

[0035] The outer diameter of the cylindrical shell is based on the diameter of the spring that is intended to be used. The spring that is intended to be used may be a helical push spring, with predetermined pitch, thread diameter, and spring diameter. For example, the outer diameter may be approximately equal to the diameter of the spring. For another example, the outer diameter may be larger than the inner diameter of the spring.

[0036] When the first part 11 and the second cart 12 are connected to form a cylindrical shell, the groove 13 forms a continuous groove 13 around the cylindrical shell. The groove 13 is for accommodating the spring that is intended to be used. Accordingly, the width of the groove 13 is based on the predetermined thread diameter of the spring. For example, if the groove 13 has a width that is smaller than the predetermined thread diameter, the spring may be partly accommodated into the groove 13. For another example, if the groove 13 has a width equal to the diameter of the spring, the spring may be accommodated up to fully into the groove 13, depending on the depth of the groove 13. For yet another example, if the groove 13 has a width greater than the diameter of the spring, the spring may also be accommodated up to fully into the groove 13, depending on the depth of the groove 13. However, in this example, in operation, the spring may move relative to the spring holding device 1, which could be less preferred.

[0037] The groove wraps around the spring holding device 1 with a pitch based on the predetermined pitch. In particular, the pitch of the groove 13 may be the same as the predetermined pitch of the spring, so that the spring fits into the groove 13 all along the longitudinal direction of the spring holding device 1.

[0038] Figure 1 schematically shows that the groove wraps around the spring holding device twice. Of course, this is merely an example and the groove may wrap around a different number of times. For example, the groove may only wrap around once. For another example, the groove may wrap around three, four, or more times. Furthermore, the skilled person appreciates that the number of times that the groove wraps around the spring holding device need not be an integer.

[0039] In a preferred embodiment, the groove 13 is shaped such that when the spring is accommodated inside the groove 13, the spring snugly fits and a surface of the spring holding device 1 with accommodated spring is essentially even. For example, the groove 13 may be shaped with a width essentially equal to the predetermined thread diameter, a depth essentially equal to the predetermined thread diameter, and a pitch essentially equal to the predetermined pitch. As further discussed below, such an arrangement may allow for a bellow that is dust proof or water proof.

[0040] Figure 1 schematically shows that the first part 11 is mechanically connectable to the second part 12. For this mechanical connection, pins 14a and 14b are provided. The pins 14a and 14b fit into corresponding holes (not shown). Figure 1 schematically shows that the pins 14a and 14b are oriented in a plane substantially perpendicular to a longitudinal axis of a bellow to be formed. When the bellow is in use, it is to be expected that the spring holding device 1 will be subj coted to forces primarily in the direction of the longitudinal axis. By orienting pins in the plane substantially perpendicular to this direction, the risk of the two parts disconnecting while the assembled bellow is in use is mitigated. Of course, the skilled person appreciates that additional or alternative connections are also possible. For example, the first part 11 and the second part 12 can be connected magnetically, or using an alternative mechanical connection, such as dovetail joints. Furthermore, it is possible to not use any connectors at all, because the spring itself already contributes to keeping the two parts together.

[0041] Figure 2 schematically shows a bellow 2.

[0042] The bellow 2 that is schematically shown in Figure 2 comprises a spring holding device 1, a cover 21, and two clamps 22. Furthermore, Figure 2 schematically shows a handle 15, a machine part 23, and a zip 24.

[0043] The spring holding device 1 schematically shown in Figure 2 may be similar to the spring holding device 1 schematically shown in Figure 1. Although only one spring holding device 1 is visible in Figure 2, the skilled person appreciates that a bellow, for example the bellow schematically shown in Figure 2, may comprise multiple spring holding devices 1, for example spring holding devices 1 similar to the spring holding device 1 schematically shown in Figure 1.

[0044] Figure 2 schematically shows that the spring holding device 1 is positioned at an end of the bellow 2. Additionally or alternatively, a spring holding device 1 may be positioned at another end of the bellow 2 and/or at an intermediate position along the bellow 2.

[0045] The bellow 2 may, for example, be formed by rotating a spring (not visible in

Figure 2) around the machine part 23, forming the spring holding device 1 around the machine part 23, screwing the spring holding device 1 into the spring, covering the spring with the cover 21, and clamping the cover 21 to the spring holding device 1 using at least one of the clamps 22.

[0046] Figure 2 schematically shows that the spring holding device 1 comprises a handle 15. Attaching a handle to the spring holding device 1 may make it easier to screw the spring holding device 1 into the spring. The skilled person appreciates that it is alternatively possible to screw the spring holding device 1 into the spring when the spring holding device does not comprise a handle 15. Furthermore, the skilled person appreciates that many different shapes of handle are possible. The skilled person appreciates that whether or not to provide the spring holding device 1 with a handle 15 as well as, if a handle 15 is to be provided, which shape the handle 15 should be may depend on the intended position of the spring holding device 1, various dimensions of the bellow 2, properties of the machine in which the bellow 2 is to be used, and/or other technical limitations and/or considerations.

[0047] The cover 21 may comprise any suitable material. The choice of material may depend on, for example, the machine or environment the bellow 2 is intended to be used in. For example, if there is a risk of fire, a fire-retardant material may be used. For example, if the machine and/or the environment produces a large amount of heat, a heat- resistant material may be used. For example, if the machine is used in the food industry, a material suitable for use in the food industry may be used. For example, if the flow of air around the machine should be controlled an airtight material may be used. For example, materials exhibiting combinations of the above properties and/or further properties may be used.

[0048] The cover 21 may be removable from the spring. Although it is possible to permanently attach the cover 21 to the spring during assembly, a removable cover 21 may be advantageous. For example, a removable cover may be more easily replaced, because the cover may then be removed without needing to remove the entire bellow 2.

Replacing a cover 21 may be useful, for example when the cover 21 gets worn out, damaged and/or dirty. Because the cover 21 is exposed to the environment, the cover 21 is more likely to get worn out, damaged, and/or dirty. The old cover may then be removed and replaced with a new cover. The replacement can be relatively quick, so that there is little down time of the machine. The old cover can be cleaned or recycled. A removable cover may be particularly advantageous when the bellow 2 is used for a machine in the food industry, because pieces of food might stick to the cover 21. Accordingly, by replacing the cover 21 regularly and/or when changing recipe, hygiene may be improved and contamination risks may be mitigated, while productivity can be kept high.

[0049] Figure 2 schematically shows that the cover 21 comprises a zip 24. Because the cover 21 schematically shown in Figure 2 comprises the zip 24, the cover 21 is removable. In Figure 2, the zip 24 is arranged such that, when the cover 21 is covering the spring, the zip 24 wraps around the spring. This arrangement of the zip 24 may be particularly advantageous, because it allows for tension on the zip 24 to be spread around the bellow. However, the skilled person appreciates that alternative ways of arranging the zip 24 are possible. Furthermore, a removable cover 21 may be provided in alternative ways. For example, instead of a zip 24, a removable cover 21 may comprise one or more of a Velcro strip, buttons, hooks and eyes, afer sticky tape. Also, the skilled person appreciates further ways of making the cover 21 removable are possible.

[0050] The clamps 22 are for clamping the cover 21 to the spring holding device 1.

Various kinds of clamps 22 may be used. Figure 2 schematically shows that both clamps 22 are band clamps, in particular worm drive hose clamps. Of course, different kinds of clamps are also possible. These different kind of clamps include, for example, spring clamps, wire clamps, ear clamps, and/or other clamps available to the skilled person.

[0051] Figure 2 schematically shows that there are two identical clamps 22. Preferably, the number of clamps 22 is equal to the number of spring holding devices 1. In practice, it may be convenient if the clamps 22 are identical. However, the skilled person appreciates that there may be circumstances in which it is instead more convenient when there are multiple different kinds of clamps 22 used for a single bellow 2.

[0052] The clamps 22 are for clamping the cover 21 to the spring holding device 1.

Preferably, the cover 21 is clamped to each spring holding device 1 of the bellow 2 by a corresponding clamp 22. Although it is possible to have a spring holding device | to which the cover 21 is not clamped, for example for guiding the spring, the cover 21 will be more firmly attached when the cover 21 is clamped to each spring holding device 1.

The skilled person appreciates that clamping the cover 21 to a spring holding device 1 is preferable over clamping the cover 21 to the spring. This is because clamping the cover 21 to a substantially even surface with the width of the clamp 22 is desirable.

Furthermore, the surface to which the cover is clamped should preferably not vary in shape during operation. So, clamping the cover 21 to the spring holding device 1 1s more convenient than clamping the cover to the spring.

[0053] Depending on the groove 13 of the spring holding device 1, the spring holding device | with mounted spring may have an essentially even outer circumferential surface.

In this case, the clamping of the cover 21 to the spring holding device 1 using the clamp 22 may be particularly tight and snugly fitting. This allows for the clamping of the cover 21 to be dustproof, water proof, and/or airtight. When the cover 21 itself is likewise dustproof, water proof, and/or airtight, for example by providing a cover 21 of an appropriate material available to the skilled person, the bellow 2 may be dustproof, water proof, and/or air tight.

[0054] The machine part 23 can be any machine part desired to be covered by the bellow 2. For example, the machine part 23 may comprise at least one cable and/or movable part, such as a hinge, cylinder, spindle, and/or other rotatable part. The skilled person appreciates that the machine part 23 itself is not part of the bellow 2.

[0055] The bellow 2 may be suitable for covering a machine part 23 of relatively small diameter. For example, the diameter of the machine part 23 at most 40 mm (or 4 cm), preferably at most 30 mm (or 3 cm), more preferably at most 20 mm (or 2 cm), most preferably at most 10 mm (or | cm). A reason for this lies in the way in which the bellow may be assembled, as further discussed below.

[0056] Additionally or alternatively, the bellow 2 may be suitable for covering a machine part 23 that is in a relatively tight surrounding. In operation, the bellow 2 will be compressed in a longitudinal direction. Because the bellow 2 comprises a spring, as opposed to conventional bellows such as accordion bellows, the compression is absorbed by a compression of the spring, which means that there is no substantial increase in bellow diameter when the bellow 2 1s compressed. This allows for the bellow 2 to be used around machine parts 23 in machines in which space is tight.

[0057] Figure 3 schematically shows a partially assembled bellow. The partially assembled bellow schematically shown in Figure 3 may additionally or alternatively be considered to be an assembly of components for a bellow, wherein at least some of the components of the assembly are in an assembled state.

[0058] The partially assembled bellow schematically shown in Figure 3 comprises two spring holding devices 1, and a spring 25. Furthermore, Figure 3 schematically shows a handle 15, a machine part 23, and a cover 21 comprising a zip 24.

[0059] The partially assembled bellow schematically shown in Figure 3 may be similar to the fully assembled bellow schematically shown in Figure 2, when the partially assembled bellow in Figure 3 is fully assembled. For example, any of the parts schematically shown in Figure 3 may be the same as a corresponding part schematically shown in Figure 2. Furthermore, either or both of the spring holding devices 1 schematically shown in Figure 3 may be similar to the spring holding device 1 schematically shown in Figure 1. Many of the components schematically shown in

Figure 3 may be the same as those schematically shown in Figure 1 and/or Figure 2, and a detailed description thereof will be omitted here.

[0060] Figure 3 schematically shows that both spring holding devices 1 are screwed into the spring 25. The partially assembled bellow comprising the spring holding devices 1 and the spring 25 is surrounding the machine part 23. Figure 3 schematically shows that one of the spring holding devices 1 comprises a handle 15, while the other spring holding device 1 does not. As also noted above, when a bellow comprises multiple spring holding devices 1, these need not be identical. Figure 3 schematically shows that the spring holding devices 1 are located at both ends of the spring 25. This allows for a convenient attachment of the cover 21. As also noted above, it is additionally or alternatively possible that one or more spring holding devices are positioned at intermediate positions of the spring 25. For example, a bellow may comprise spring holding devices 1 at both ends and additionally comprise a spring holding device 1 at an intermediate position.

Furthermore, as also noted above, it is possible that a bellow comprises only a single spring holding device 1, which may be positioned at either end or at an intermediate position.

[0061] The cover 21 schematically shown in Figure 3 is not covering the spring 25. In an assembled state, the cover 21 covers the spring 25. In an assembled state, the zip 24 will be closed. Other properties of the cover 21 schematically shown in Figure 3 may be the same as for the cover 21 schematically shown in Figure 2.

[0062] The machine part 23 schematically shown in Figure 3 may be the same as the machine part 23 schematically shown in Figure 2.

[0063] The spring 25 schematically shown in Figure 3 is a helical push spring 25 with a predetermined pitch, thread diameter, and diameter. Helical push springs with varying properties are commercially available. The skilled person is capable of choosing a helical push spring with the desired properties for the bellow to be formed. For example, the skilled person is able to predetermine the pitch, thread diameter, and diameter depending on the precise purpose that the assembled bellow will be required for.

[0064] Figure 4 schematically shows an end of a bellow 2.

[0065] The end of the bellow 2 schematically shown in Figure 4 comprises a spring holding device 1, a cover 21 comprising a zip 24, and a clamp 22. The end of the bellow 2 is surrounding a machine part 23. Figure 4 only shows an end of the bellow 2 and does not show the complete bellow. Many of the components schematically shown in Figure 4 may be the same as those schematically shown in Figure 1, Figure 2, and/or Figure 3, and a detailed description thereof will be omitted here.

[0066] Figure 4 schematically shows that the zip 24 of the cover 21 is partially opened.

In order to open the zip 24, the clamp 22 has been somewhat loosened compared to a situation in which the bellow 2 is fully assembled and may be in operation.

[0067] Figure 4 schematically shows that the damp 22 is positioned over the spring holding device 1. In this way, when the zip 24 is closed, the clamp 22 may be tightened further to enable a tight clamping of the cover 21 to the spring holding device 1.

[0068] In operation, the two parts 11, 12 of the spring holding device 1 are held together by the spring 25 and may be further secured by additional connections, such as pins 14a and 14b. Due to the groove 13, the spring 25 is fixed with respect to the spring holding device 1. The combination of spring 25 and one or more spring holding devices 1 may be secured to the machine part 23 due to the inner diameter of the spring holding device 1 corresponding to the a diameter of the machine part 23. Alternatively, the inner diameter of the spring holding device 1 may be larger than the diameter of the machine part 23, in which case the combination of spring 25 and one or more spring holding devices 1 may be held in place by outside pressure on the ends of the spring 25 (or on one or more of the spring holding devices 1, which cause indirect outside pressure on the ends), which causes a compression of the spring 25 and a holding in place of the combination. The cover 21 may be closed with the zip 24 and is held in place by clamping the cover 21 to the spring holding devices 1 using clamps 22. Because the spring holding devices 1 are broad enough for the clamps 22 to clamp the cover 21 to the spring holding devices 1 and because, in operation, the shape of the spring holding devices does not change, the various parts of the bellow 2 remain connected during operation.

[0069] Figure 5 schematically shows a method of protecting a machine part using a bellow.

[0070] In step 51, a spring is rotated over a machine part. The spring may be a spring 25 described above and the machine part may be a machine part 23 described above.

Because springs are relatively open, they be rotated around machine parts, even if there is not much space around the machine part, if the machine part has a small diameter, and/or if the machine the machine part is in should not be disassembled.

[0071] In step 52, one or more spring holding devices are assembled. The spring holding devices may be spring holding devices 1 described above. The spring holding devices are assembled by connecting their parts such that the machine part ends up in an inside of the cylindrical shell of the spring holding device 1.

[0072] Optionally, steps 51 and 52 may be performed in reverse order. Furthermore, if there are multiple spring holding devices, step 52 may be performed for some of the spring holding devices before step 51 and for other spring holding devices after step 51.

[0073] In step 53, the spring holding devices are screwed into the spring 25. Of course, additionally or alternatively, the spring 25 may be screwed into the spring holding devices 1. If there are multiple spring holding devices 1, some of these may be screwed into the spring 25, while for others the spring 25 may be screwed into the spring holding devices.

[0074] Each spring holding device 1 comprises a groove 13 for accommodating the spring 25. The dimensions of the groove 13 depend on predetermined dimensions of the spring 25. In this way, the spring 25 and spring holding devices 1 may be connected to each other.

[0075] In step 54, the combination of spring holding devices 1 and spring 25 is covered by a cover, for example the cover 21 described above. The cover is then closed and clamped to the spring holding devices 1 using clamps, for example using clamps 22 described above.

[0076] By performing this method, a bellow may be formed around the machine part.

Because the various components are assembled around the machine part, the bellow may be assembled when space is limited. As described above, the components are such that after assembly they remain connected together in operation. Furthermore, a bellow as described above may not significantly increase in diameter when compressed. Also, by choosing an appropriate material for the cover and by tightly clamping the cover, a bellow described above may be made dust proof, water proof, and/or airtight.

[0077] Figures 6A-6C schematically show a compressed bellow.

[0078] The compressed bellow schematically shown in Figures 6A-6C may be similar to the bellow 2 schematically shown in Figure 2. Many of the components schematically shown in Figure 6 may be the same as those schematically shown in Figure 1, Figure 2,

Figure 3 and/or Figure 4, and a detailed description thereof will be omitted here.

[0079] Figure 6A schematically shows a side view of a compressed bellow. The bellow schematically shown in Figure 6A comprises a spring holding device comprising a first part 11 and a second part 12, a cover 21 with a zip 24, and a clamp 22. The bellow comprises a helical spring, which is however not visible, because the helical push spring is covered by the cover 21.

[0080] The compressed bellow shown in Figure 6A is in a compressed state. Bellows may, for example, be compressed by applying a force on either or both ends of the bellow.

Because the bellow is in a compressed state, a longitudinal length of the bellow is shorter than it would have been had the bellow not been in a compressed state.

[0081] The radius of certain bellow designs of the related art may expand when such a bellow of the related art is in a compressed state. As discussed above, such an expanded radius may be inconvenient if the bellow is to be used in a machine in which space is constrained.

[0082] Figure 6A shows that a bellow comprising a helical push spring does not substantially expand in radius when compressed. This is because the helical push spring does not expand in radius. while the cover 21 merely slightly wrinkles. The ends of the cover 21 remain clamped to the spring holding devices through the clamps 22.

Furthermore, because the zip 24 wraps around the bellow, the pressure on the zip 24 is also spread evenly.

[0083] Figure 6B schematically shows a front view of the compressed bellow of Figure

GA. It can be seen that the cover 21 does not substantially extend beyond the radius of the two parts 11, 12 of the spring holding device.

[0084] Figure 6C schematically shows another view of the compressed bellow of Figures

GA and 6B.

[0085] Figures 7A and 7B schematically show various components of a bellow. In particular, Figures 7A and 7B schematically show an assembled bellow, in which various components have been made transparent or have been omitted from the drawings, in order to show other components more clearly. The skilled person understands these drawings to not necessarily be realistic, but merely to show further technical details.

[0086] Figure 7A schematically shows a side view of a bellow. The bellow schematically shown in Figure 7A may be similar to the bellow 2 schematically shown in Figure 2.

Many of the components schematically shown in Figure 6 may be the same as those schematically shown in Figure 1, Figure 2, Figure 3 and/or Figure 4, and a detailed description thereof will be omitted here.

[0087] Figure 7A schematically shows a spring holding device 1 comprising a first part 11 and a second part 12, a zip 24, and a helical push spring 25. In order to more clearly show these components, the cover 21 and clamp 22 are not shown in Figure 7A. The skilled person appreciates that these components may nevertheless be present in a practical implementation of the bellow.

[0088] As can be seen in Figure 7A, the spring holding devices 1 are screwed into the helical push spring 25. In this way, the helical push spring 25 holds the parts 11, 12 together. It can also be seen in Figure 7A that the helical push spring 11 has a thread diameter greater than the depth of the groove of the spring holding devices. In this way,

the helical push spring 25 extends slightly Sutwards from the outer circumferential surface of the spring holding devices 1. So, the outer circumferential surface of the spring holding devices when screwed into the helical push spring is not flat. Alternatively, it is possible to provide spring holding devices 1 with a groove depth corresponding to the thread diameter of the helical push spring 25. This alternative may allow for a bellow that is dustproof and/or waterproof and/or airtight.

[0089] As can be seen in Figure 7A, the zip 24 wraps around the bellow. This allows for a distribution of pressure all around the bellow. Nevertheless, alternative arrangements of the zip 24 are also possible. As noted above, the cover may also be closed in additional or alternative ways, that is, without using any zip, or using a zip in addition to other closures, such as a Velcro strip, buttons, hooks and eyes, and/or sticky tape.

[0090] Figure 7B shows a section of Figure 7A along the line VII B. So, Figure 7B schematically shows a bellow.

[0091] Figure 7B schematically shows that the parts 11, 12 of the spring holding devices are held together mechanically through pins 14a, 14b, with corresponding holes.

[0092] It can also be seen in Figure 7B that the helical spring 25 is accommodated in the groove of the parts 11, 12. The spring extends outside of the groove, so that an outer circumferential surface is not flat.

[0093] The various Figures shown above show examples in which there are two spring holding devices 1 screwed into the helical push spring 25. However, as also noted above, the number of spring holding devices 1 is not particularly limited to 2. It is possible to have only one spring holding device 1, or to have three or more spring holding devices 1. Furthermore, and as also noted above, although the various Figures show examples in which the spring holding devices 1 are placed at ends of the bellow 2, it is additionally or alternatively possible to screw the spring holding devices 1 into the helical push spring 25 further, such that these spring holding devices 1 become positioned at an intermediate position of the helical push spring 25.

[0094] The various Figures shown above show examples in which the spring holding device 1 comprises two semi-cylindrical shell shaped parts 11 and 12. However, as also discussed above, it is possible to provide a spring holding device comprising a different number of parts, which may have different shapes. A single spring holding device may comprise a plurality of parts differing in shape. The skilled person appreciates that the main consideration for the spring holding device is the overall shape, while the further choices of which parts to use may depend on practical considerations regarding ease of manufacturing and/or assembly and/or use. Similarly, although the various Figures shown above show examples in which the parts of the spring holding device 1 are connectable through pins 14a, 14b, the shape of mechanical connectors is optional, as well as whether mechanical connectors should be used at all. For example, if the spring holding device 1 comprises a plurality of parts, these may be held together using non- mechanical connections, for example through the use of magnets and/or glue. Moreover, because the spring holding device 1 is intended to be screwed into the helical push spring 25, the helical push spring 25 also contributes to holding the various parts of the spring holding device 1 together, which can be sufficient for certain applications.

[0095] The various Figures shown above show examples in which the cover 21 is removable. Although a removable cover 21 is convenient to replace, it is alternatively possible to provide a bellow 2 with a cover 21 that is non-removable. For example, it is possible to assemble the bellow by gluing the sides of a cover 21 together.

[0096] The various Figures shown above show examples in which the clamp 22 is a band clamp, in particular a worm drive hose clamp. However, as also described above, additional or alternative clamps may be used for clamping the cover 21 to the spring holding device 1.

[0097] In the foregoing description of the figures, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the scope of the invention as summarized in the attached claims.

[0098] In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

[0099] In particular, combinations of specific features of various aspects of the invention may be made. An aspect of the invention may be further advantageously enhanced by adding a feature that was described in relation to another aspect of the invention.

[00100]lt is to be understood that the invention is limited by the appended claims only.

In this document and in its claims, the verb "to comprise" and its conjugations are used in their non-limiting sense to mean that items following the word are included, without excluding items not specifically mentioned. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the element is present, unless the context clearly Tires that there be one and only one of the elements.

The indefinite article "a" or "an" thus usually means "at least one". Terms such as "first" or "second" may simply be used to distinguish the component from other components in question, and do not limit the components in other aspects (such as importance or order).

Claims

Claims l. An assembly for a bellows (2), comprising: a helical compression spring (25); and a first spring holder (1), the spring holder (1) comprising: a first portion (11); and a second portion (12) connectable to the first portion (11) to form a cylindrical sleeve, an outer circumferential surface of the cylindrical sleeve being provided with a groove (13) for accommodating the helical compression spring (25), the groove (13) winding around the outer circumferential surface of the cylindrical sleeve at a pitch corresponding to a pitch of the helical compression spring (25), so that when the first portion (11) is connected to the second portion (12), the first spring holder (1) is screwable into the helical compression spring (25)

is.

2. The assembly of claim 1, wherein the first part (11) and the second part (12) have a semi-cylindrical shape.

3. The assembly according to any one of claims 1-2, wherein the first part (11) and the second part (12) are mechanically connectable.

4. The assembly of claim 3, wherein the first part (11) and the second part (12) are connectable by pins (14a, 14b) and associated holes, the pins (14a, 14b) being substantially perpendicular to the cylinder axis of the cylindrical sleeve.

5. The assembly according to claim 3, wherein the first part (11) and the second part (12) are connectable by means of dovetail joints.

6. The assembly of any one of claims 1 to 5, wherein the first spring holder (1) further comprises a handle (15).

7. The assembly according to any one of claims 1 to 6, wherein the depth of the groove (13) corresponds to the wire diameter of the helical compression spring (25).

8. The assembly according to any one of claims 1 to 7, wherein an inner diameter of the cylindrical sleeve is at most 40 mm, preferably at most 30 mm, more preferably at most 20 mm, most preferably at most 10 mm.

9. Bellows (2), comprising: an assembly according to any one of claims 1 to 8; a sleeve (21) for covering the helical compression spring (25); and a clamp (22) for clamping the sleeve (21) to the outer surface of the first spring holder (1).

10. The bellows (2) of claim 9, wherein the helical compression spring has a first end and the first spring holder (1) is screwed into the helical compression spring proximal to the first end.

11. The bellows (2) of claim 10 further comprising a second spring holder (1), the helical compression spring (25) having a second end and the second spring holder (1) being screwed into the helical compression spring proximal to the second end.

12. Bellows (2) according to any one of claims 9 to 11, wherein the sleeve (21) is removable from the helical compression spring (25).

13. Bellows (2) according to claim 12, wherein the cover (21) comprises a zipper (24).

14. Bellows (2) according to any one of claims 9 to 13, wherein the sleeve (21) comprises at least one of a fire-retardant material, a heat-resistant material, a material suitable for use in the food industry and/or an airtight material.

15. Bellows (2) according to any one of claims 9 to 14, wherein the clamp (22) comprises a clamp band (22)

is.

16. Bellows (2) according to claim 15, wherein the clamp (22) is a worm gear hose clamp (22).

17. Machine part provided (23) with a bellows (2) according to any one of claims 9 to 16, wherein the machine part (23) has a substantially elongated shape and wherein a major axis of the substantially elongated shape corresponds to a major axis of the bellows (2).

18. Machine part (23) according to claim 17, wherein the machine part (23) comprises a hinge, a cylinder, a spindle, a cable, or a rotatable part.

19. Machine comprising a machine part (23) according to any one of claims 17-

18.

20. A method of protecting a machine part using a bellows according to any one of claims 9 to 16, comprising: rotating (51) the helical compression spring over the machine part; connecting (52) the first part and the second part of the first spring holder so that the machine part is located in an interior of the cylindrical sleeve; screwing (53) the first spring holder into the helical compression spring; and clamping (54) the spring to the outer surface of the first spring holder.