NL2020301B1 - Modular conveyor chain - Google Patents

Abstract

Modular conveyor chain, comprising a number of successive, mutually hingedly connected modules. The modules each comprise a link portion made of sheet metal that has a body part that forms a conveying surface. The body part is provided with a centrally located coupling piece on one side thereof, and a pair of interspaced coupling pieces on an opposite side thereof that include an interspace in between. The coupling pieces each extend from the body part to loop around a receiving space that is positioned lower than the body part. The coupling pieces of successive modules cooperate to form a hinge assembly because the centrally located coupling piece of a link portion is received in the interspace between the interspaced coupling pieces of a link portion of a successive module, and because a hinge pin extends through aligned receiving spaces of the cooperating coupling pieces. The modular conveyor chain further includes a plastic bearing element received between the centrally located coupling piece and the hinge pin, characterized in that the hinge pin has a substantially constant cross section.

Description

Patent center

Θ 2020301

(2?) Application number: 2020301 (22) Application submitted: January 22, 2018

Int. CL:

B65G 17/08 (2018.01)

0 Application registered: 0 Patent holder (s): July 29, 2019 Rexnord FlatTop Europe B.V. in 's-Gravenzande. 0 Request published: 0 Inventor (s): 0 Patent granted: Cornells Hendrik Mijndert Menke July 29, 2019 in 's-Gravenzande. 0 Patent issued: July 29, 2019 0 Authorized representative: ir. C.M. Jansen et al. In The Hague.

54) Modular conveyor chain

57) Modular conveyor chain, including a number of successive, mutually hingedly connected modules. The modules each include a link portion made of sheet metal that has a body part that forms a conveying surface. The body part is provided with a centrally located coupling piece on one side, and a pair of interspaced coupling pieces on an opposite side, that includes an interspace in between. The coupling pieces each extend from the body part to walk around a receiving space that is positioned lower than the body part. The coupling pieces of successive modules cooperate to form a hinge assembly because the centrally located coupling piece of a link portion is received in the interspace between the interspaced coupling pieces of a link portion of a successive module, and because a hinge pin extends through aligned receiving spaces of the cooperating coupling pieces. The modular conveyor chain further includes a plastic bearing element received between the centrally located coupling piece and the hinge pin, characterized in that the hinge pin has a substantially constant cross section.

NL B1 2020301

This patent has been granted regardless of the attached result of the research into the state of the art and written opinion. The patent differs from the documents originally submitted. All submitted documents can be viewed at the Netherlands Patent Office.

P117555NL00

Title: Modular conveyor chain

The invention relates to a modular conveyor chain, including link portions made of sheet metal.

Metal modular conveyor chains are generally known, and are used for example for conveying glass bottles.

Metal conveyor chain modules are so conventional that they have been standardized in DIN 8153 / ISO 4348. The DIN 8153 / ISO 4348 standardization includes the sizes and dimensions of so called flat-top chain modules, eg the pitch between chain modules, the hinge pin diameter and eg how the coupling pieces or the portions of the modules need to be curled. The standardization applies to chains with both single-hinged and double-hinged assembly.

The hinge assembly consists of hinge eyes that walk around a hinge receiving space to retain a hinge pin.

The customary chains are manufactured by punching chain link blanks from sheet metal resulting in a base form for a link portion. The blanks consist of an elongate conveying body and tongues extending from longitudinal sides of the conveying body to form coupling pieces. The tongues are to walk around a receiving space for a hinge pin. One tongue is centrally located on one longitudinal side of the elongate conveying body and two spaced apart tongues are placed on the opposite longitudinal side. The two spaced apart tongues on one longitudinal side are arranged with an interspace such that when the tongues are to form coupling pieces, the centrally placed coupling piece is received in the interspace between the two spaced separate coupling pieces on a consecutive module. Consecutive metal conveyor chain modules are linked together by retaining metal hinge pins in hinge receiving spaces so adjacent modules can rotate with respect to each other on an axis transverse to the conveyor chain. During use the hinge pins and hinge eyes are subject to wear and tear at the area of rotation, which necessitates the replacement of pins and hinge eyes over time. It is customary to lubricate the chain to reduce hinge pin wear. However, lubrication is cumbersome. Maintaining the right amount of lubrication is not simple, and excess lubricant may easily cause slippery areas around the conveyor system, and pollution of the conveyor. In certain food processing industries lubrication is prohibited, which further accentuates the problem caused by wear.

In U.S. Pat. No. 3363745 a conveyor chain has been proposed that has a plastic sleeve to reduce the wear of the hinge pins and hinge eyes without lubrication, such that the conveyor chain may be used where lubrication is prohibited. The proposed plastic sleeve has a helical split and is fit around an intermediate reduced diameter portion or a special hinge pin. In practice, the manufacture of this chain has proven to be too costly, and the reliability too low.

An object of the invention therefore is to provide a modular conveyor chain that mitigates the above mentioned drawbacks, in particular a steel modular conveyor chain that can be used without lubrication, that is reliable and that can be manufactured cost-effectively.

Thereto, the invention provides a modular conveyor chain, including a number of successive, mutually hingedly connected modules, which modules each include a link portion made or sheet metal that has a body part that forms a conveying surface, which body part is provided with a centrally located coupling piece on one side, and a pair of interspaced coupling pieces on a opposite side, that include an interspace in between, which coupling pieces each extend from the body part to walk around a receiving space that is positioned lower than the body part, following coupling pieces of successive modules cooperate to form a hinge assembly because the centrally located coupling piece of a link portion is received in the interspace between the interspaced coupling pieces of a link portion of a successive module, and because a hinge pin extends through aligned receiving spaces or cooperating coupling pieces, further including a plastic bearing element received between the cen trally located coupling piece and the hinge pin, characterized in that the hinge pin has a substantially constant cross section.

By using a hinge pin with a substantially constant cross section, a low cost cylindrical hinge pin can be used, which saves costs. In addition, due to its constant cross section, the hinge pin can be inserted axially into the bearing element smoothly, which facilitates assembly. A costly hinge pin with a reduced diameter section may thus be omitted. The ends of the hinge pin may be at the location of the spaced apart or interspaced coupling pieces, if desired, be provided with knurling on the mantle surface in a conventional way. The bearing element may extend along a part of the hinge pin, e.g., only at the location of the central coupling element. It may, however, also extend along the full length of the hinge pin, e.g. also at the location of the interspaced coupling pieces. In case the bearing element extends over the hinge pin only at the location of the central coupling element, the interspaced coupling pieces may be slightly downward or the interspaced coupling pieces may be provided with filler elements to align the hinge receiving spaces of the interspaced coupling pieces with the receiving space or the central coupling element.

The hinge pin may have a diameter that corresponds to the diameter of a standard hinge pin, in particular 6.35 mm. In addition, the hinge pin may also be chosen to have a diameter such that hinge pin and the bearing element together have a diameter that conforms to the diameter or a standard hinge pin, eg when the bearing element extends along the full length of the hinge pin , ie also under the interspaced coupling pieces. This way, a standard chain link may be used.

When the bearing element comprises a profile section that extends along a longitudinal axis of the hinge pin, it can be achieved that the bearing element can absorb an axial load relatively easily. This facilitates axial insertion of the bearing element into the hinge assembly and / or axial insertion of the hinge pin into the bearing element. The profile section may have a closed cross section, e.g. in case or a tubular profile section. The profile section can also have an open cross section, e.g. in case or a C-shaped profile section. In case the bearing element is embodied as a profile section with an uninterrupted continuous cross section along its full length, the bearing element may be manufactured relatively cost effectively as an extrusion profile. The bearing element may also be manufactured cost effectively by injection molding, e.g. if the cross section or the profile varies locally along its axis.

When the bearing element has a wall thickness that varies along the circumference of its cross section, it can be achieved that the wall is thicker at locations where the contact forces on the bearing element between the hinge pin and for example the central coupling piece are higher during rotation. Additionally or alternatively, the varying wall thickness of the bearing element can adjust the position of the hinge pin within the receiving space of the coupling pieces. By using a bearing element that extends over the hinge pin only at the location of the central or centrally located coupling piece and having a varying wall thickness, the hinge receiving spaces of the interspaced coupling pieces and the receiving space of the central coupling piece may remain substantially aligned without eg the need to bend the interspaced coupling pieces slightly downward or to provide filler elements in the interspaced coupling pieces. This way, a standard chain link may be used or the use of filler elements in the interspaced coupling pieces can be omitted, which saves costs.

By providing a bearing element that is open or flattened at a top side that faces the body part, the hinge receiving spaces of the interspaced coupling pieces and the receiving space of the central coupling piece may remain substantially aligned, without eg the need to bend the interspaced coupling pieces slightly downward. This way, a standard chain link may be used while the bearing element may reduce wear at the area of rotation. In case the bearing element is open at a top side that faces the body part, this may ease axial insertion of the bearing element into the hinge assembly and / or axial insertion of the hinge pin into the bearing element.

The receiving space of the interspaced coupling pieces may, during use, retain the hinge pin and / or hinge pin and the bearing element together tightly by clamping. The central coupling piece may then be non-clamping,

e.g. with a loose fit, to allow rotation between consecutive hingedly connected modules or the modular conveyor chain around the hinge pin.

The receiving space of the interspaced coupling pieces may be a substantial round hinge eye. In addition, the centrally located coupling piece may form a substantial oblong hinge eye. This way, the interspaced coupling pieces may, during use, retain a hinge pin tightly while substantially oblong hinge allows space for receiving a bearing element. Advantageously, in case a bearing element is used that extends over the hinge pin only at the location of the central coupling piece with a substantial oblong hinge eye, the bearing element may be retained in the place by the blocking action of the interspaced coupling members. The manufacture of oblong hinge eyes is customary in modular conveyor chains that can bend and negotiate turns. This way, a standard bend chain can be used.

The hinge pin may also be chosen to have a standard diameter such a hinge pin and the bearing element together have a diameter that is larger than the diameter of a standard hinge pin, eg when the bearing element extends along the full length of the hinge pin , ie also under the interspaced coupling pieces. This way, the receiving spaces of the chain link may be adjusted such that the bearing element can axially extend along the hinge pin and reach under the interspaced coupling pieces.

By allowing the interspaced coupling pieces to clamp onto the hinge pin via the bearing element, it may be achieved that the hinge pin and bearing element are retained tightly, such that the hinge pin and bearing element will not migrate axially and slip out. The ends of the hinge pin may be at the location of the spaced apart or interspaced coupling pieces, if desired, be provided with knurling on the mantle surface in a conventional way to counteract the hinge pin will migrate axially and slip out.

By providing the bearing element with a stop on its outer mantle, it may be achieved that the bearing element is retained in place after it has been axially inserted into the receiving spaces of the chain links. In addition, the stop may facilitate retaining the bearing element in place during consecutive axial insertion of the hinge pin into the hinge assembly by forming an impediment that may counteract axial migration or the bearing element during axial insertion of the hinge pin. The stop may for example include a radial outward ridge that extends axially along the outer mantle of the bearing element, which is positioned between a free end of a coupling piece and the body part, such that rotation of the bearing element can be counteracted. The stop may for example include a radial outward ridge that extends circumferentially along the outer mantle of the bearing element, which is positioned between adjacent sides of the central coupling piece and an interspaced coupling piece, such that migration of the bearing element transverse to the conveyor chain may be counteracted. The stop may also include two axially spaced apart, radially outwardly extending ridges that extend circumferentially along the outer mantle of the bearing element, which are each positioned at opposite sides of the central coupling piece, such that migration of the bearing element transverse to the conveyor chain may be further counteracted. The stop may also facilitate installation and / or assembly of the modular conveyor chain.

By providing the bearing element with a stop on its inner mantle, for example a stop including a flange at the end of the bearing element that extends radially inward from the mantle, it may have been achieved that the stop cooperates with an end face of the hinge pin to move together during axial insertion into the receiving spaces or the chain links.

When the bearing element comprises an inner diameter that is undersized relative to the diameter of the hinge pin, it may be achieved that the bearing element clamps around the hinge pin.

By using a bearing element that comprises expansion recesses along its mantle, the bearing element may expand radially such that axial insertion or the bearing element into the hinge assembly and / or axial insertion or the hinge pin into the bearing element is facilitated. In addition, the expansion recessions may assist tight clamping or the bearing element between the hinge pin and receiving spaces or at least the interspaced coupling pieces.

The plastic material or the bearing element may be chosen to be an engineering plastic with the desired properties, such as low-friction. This way, the bearing element has good structural properties to allow axial insertion of the bearing element into the hinge assembly and / or axial insertion of the hinge pin into the bearing element, while reducing the wear of the hinge pins and hinge eyes.

The modular conveyor chain may include a number of successive, mutually hingedly connected modules, the body part is provided with a pair or centrally located interspaced coupling pieces on one side, that includes an interspace in between, and a threefold or interspaced coupling pieces on an opposite longitudinal side that includes an interspace between each piece, following the coupling pieces of successive modules cooperating to form a hinge assembly because the pair of centrally located interspaced coupling pieces is received in the interspaces between the threefold or interspaced coupling pieces of a successive module. It will be clear to the skilled person that a variety of interspaced coupling pieces, beyond those described here, may be used in a similar manner for modular conveyor chains.

The modular conveyor chain can be assembled by axially inserting a bearing element into receiving spaces or cooperating coupling pieces or successive modules and consecutively drive a hinge pin into the hinge assembly. The bearing element may be axially retained from migrating to the conveyor chain by a stop. The bearing element may also be radially expandable, allowing the coupling pieces to clamp onto the hinge pin via the bearing element, such that the hinge pin and bearing element will not slip out. By using a bearing element that can expand radially, the assembly of the chain may be further facilitated.

It will be clear to the skilled person that the technical features of the present conveyor chain elucidated in the above paragraphs can be used advantageously in a conveyor chain not only each alone but also in any possible combination. The technical features described in the paragraphs can be isolated from the context, and the isolated technical features from the different paragraphs can be combined. Such combinations are specifically disclosed in this description.

The invention will be further elucidated on the basis of a non-limiting exemplary embodiment, which is represented in the drawings. In the drawings:

FIG. the shows a schematic perspective bottom view of a module for a modular conveyor mat according to a first embodiment of the invention;

FIG. lb shows a schematic side view of the module or Figs. la;

FIG. 2a shows a schematic perspective bottom view of a modular conveyor chain according to a second embodiment of the invention with a hinge assembly in partial cross section;

FIG. 2b shows a schematic side view or a module of the chain or Fig.

a;

FIG. 2c shows a schematic perspective view of a bearing element of the chain or FIG. 2a;

FIG. 3 shows a schematic perspective bottom view of a modular conveyor chain according to a third embodiment of the invention with a hinge assembly in partial cross section, and a hinge pin and bearing element in disassembled state;

FIG. 4 shows a schematic perspective view of an alternative bearing element for the modular conveyor chain or Fig. 3;

FIG. 5a shows a schematic perspective bottom view of a modular conveyor chain according to a third embodiment of the invention with a hinge assembly in partial cross section, and a hinge pin and bearing element in disassembled state; and

FIG. 5b a schematic perspective view of a bearing element of the chain or FIG. 5a.

It is noted that the drawings are only schematic representations of a preferred embodiment of the invention. In the drawings, identical or corresponding parts are represented with the same reference numerals.

Referring to Figs, la and lb, a module 1 for a modular conveyor chain 2 according to a first embodiment of the invention is shown. The module 1 comprises a link portion 3 made of sheet metal that has a body part 4 that forms a conveying surface S. The body part 4 is provided with a centrally located coupling piece 5 on one longitudinal side, and a pair of interspaced coupling pieces 6 on an opposite longitudinal side that includes an interspace in between. The coupling pieces 5, 6 extend from the body part 4 to walk around a receiving space 7 that is positioned lower than the body part 4. In use, coupling pieces 5, 6 or successive modules 1 cooperate to form a hinge assembly because the centrally located coupling piece 5 of a link portion 3 is received in the interspace between the interspaced coupling pieces 6 of a link portion 3 of a successive module 1, and because of a hinge pin 8 extends transverse to a conveying direction through aligned receiving spaces 7 of the cooperating coupling pieces 5, 6. In use, further a plastic bearing element 9 is included that is received between the centrally located coupling piece 5 and the hinge pin 8. In accordance with the invention, the hinge pin 8 has a substantially constant cross section . In particular, the hinge pin 8 is made of steel, and is a conventional cylindrical hinge pin 8. In this embodiment, the hinge pin has a diameter of 6.35 mm. In this embodiment, the bearing element 9 extends only at the location of the central coupling element 5. As can be seen, the interspaced coupling pieces 6 are slightly downward to align the hinge receiving spaces 7 of the interspaced coupling pieces 6 with the receiving space 7 of the central coupling element 5. The bearing element 9 further comprises a stop 10 on its outer mantle 11. In this example, the stop 10 comprises a radial outward ridge 10a that extends axially along the outer mantle 11 of the bearing element 9. The ridge 10a is positioned between a free end 12 or a coupling piece 5 and the body part 4. This way, rotation of the bearing element 9 inside the receiving space 7 or the centrally located coupling piece 5 is counteracted.

Referring to Figs. 2a-2c, a modular conveyor chain 2 according to a second embodiment of the invention is shown. The modular conveyor chain 2 comprises a number of in the conveying direction successive, mutually hingedly connected modules 1. The modules 1 have a substantial flat body part 4 that forms a conveying surface. The module 1 comprises receiving spaces 7 of the interspaced coupling pieces 6 that each form a substantial round hinge eye. The centrally located coupling piece 5 forms a substantial oblong hinge eye. Such hinge eyes are known per se, and are typically used in side flexing modular conveyor chains. The interspaced coupling pieces 6 clamp onto the hinge pin to retain the hinge pin 8, such that it will not migrate axially and slip out during use. The bearing element 9 comprises a profile section 13 that extends along a longitudinal axis of the hinge pin 8 at the location of the central coupling element 5. The bearing element 9 may, however, as an alternative also extend along the entire length of the hinge pin 8, eg also at the location of the spaced apart coupling pieces 6. As can be seen, the bearing element 9 has a wall thickness that varies along the circumference or its cross section. The bearing element 9 is also open on a top side that faces the body part 4, thus forming a C-shaped profile section. It may, however, instead have a closed cross section and be flattened at the top side that faces the body part 4. The centrally located coupling piece 5 having a substantial oblong hinge eye provides space for a bearing element 9 to be received between the hinge pin 8 and coupling piece 5, while the interspaced coupling pieces 6, having a substantial round hinge eye, retained the bearing element 9 in place, such that it will not migrate axially and slip out during use. By using a bearing element 9 that is open or flattened at the top side that faces the body part 4, the receiving spaces 7 of the interspaced coupling pieces 6 and the centrally located coupling piece 5 remain substantially aligned.

Referring to Figs. 3 and 4, a modular conveyor chain 2 according to a third embodiment of the invention is shown. In this embodiment the bearing element 9 comprises a stop 14 on its inner mantle. The stop 14 comprises a flange 14a at the end of the bearing element 9 that extends radially inward from the mantle 11. This way, the stop 14 can cooperate with an end of the hinge pin 8 to move together during axial insertion into the receiving spaces 7 of the chain links 3 and / or to provide an impediment for the hinge pin 8 as it is driven into the hinge assembly. In addition, it is used as an abutting surface that cooperates with a surface or a tool to stop axial movement or bearing element during insertion of the hinge pin. The flange 14a has an opening to allow air to pass through the hinge pin 8 is inserted and / or driven into the bearing element 9 and / or hinge assembly.

Referring to Figs. 5a and 5b, a modular conveyor chain 2 according to a fourth embodiment of the invention is shown. The bearing element 9 comprises a stop 15 on its outer mantle 11 to retain the bearing element 9 in place after it has been axially inserted into the receiving spaces 7 of the chain links 3. In addition, the stop 15 facilitates retaining the bearing element 9 in place both during consecutive axial insertion of the hinge pin 8 into the hinge assembly and during simultaneous axial insertion of the bearing element 9 with the hinge pin 8 into said receiving spaces 7. As shown, the stop 15 comprises two axially spaced apart, radially outwardly extending ridges 15a that extend circumferentially along the outer mantle 11 of the bearing element 9, which are each positioned at opposite sides of the central coupling piece 5 during use, such that migration of the bearing element is transacted to the conveyor chain. The stop 15 may, however, as an alternative include only one radial outward ridge 15a that extends circumferentially along the outer mantle 11 or the bearing element 9, which is positioned between adjacent sides of the central coupling piece 5 and an interspaced coupling piece 6. In the case of the modular conveyor chain 2 includes a variety of interspaced cooperating coupling pieces 5, 6, it will be clear to the skilled person that the stop 15 can be a variety of ridges 15a that can each be positioned at opposite sides of central coupling pieces

5. The stop 15 also facilitates installation and / or assembly of the modular conveyor chain by impeding axial migration of the bearing element 9 during axial insertion of the hinge pin 8 into the hinge assembly. The bearing element 9 further comprises expansion recesses 16 along its mantle 11, such that the bearing element 9 expands radially during axial insertion of the hinge pin 8 into the bearing element. In addition, the expansion recessions 16 facilitate axial insertion of the bearing element 9 into the receiving spaces 7 of the coupling pieces 5, 6 by easing radial contraction and the bearing element 9 is clamped tightly between the hinge pin 8 and receiving spaces 7 of at least the interspaced coupling pieces 6 by radial expansion.

As for the scope of this disclosure, it is pointed out that technical features which have been specifically described may be susceptible or a functional generalization. Furthermore, it is pointed out that - as far as not explicitly indicated - such technical features can be seen separately from the context of the given example, and furthermore can be seen separately from the technical features with which they cooperate in the context of the example.

As for the scope of protection, it is pointed out that the invention is not limited to the exemplary embodiment represented here, and that many variants are possible. Such variants will be clear to the skilled person and are understood to fall within the scope of the invention as set forth in the following claims.

LIST OF REFERENCE SIGNS module modular conveyor chain link portion body part centrally located coupling piece interspaced coupling piece receiving space hinge pin bearing element stop

10a ridge outer mantle free end profile section stop

14a flange stop

15a ridge expansion recess

S conveying surface

Claims (15)

Conclusions A modular conveyor chain, comprising a number of consecutive mutually hingedly coupled modules, the modules each comprising a sheet steel link part with a body part forming a transport surface, which body part is provided on one side with a centrally placed coupling piece, and on an opposite side is provided with a pair of coupling pieces spaced apart from one another, the coupling pieces each extending away from the body part and looping around a receiving space located lower than the body part, the coupling pieces of successive modules cooperating to form a hinge system because the centrally placed coupling piece the interspace of a link part of a subsequent module is accommodated, and in that a hinge pin extends through aligned receiving spaces of the cooperating coupling pieces, further comprising a plastic bearing element accommodated between the hinge pin and the centrally placed coupling piece, with characterized in that the hinge pin has a substantially constant cross-section. A modular conveyor chain according to claim 1, wherein the bearing element comprises a profile part extending along the longitudinal axis of the hinge pin. Modular conveyor chain according to claim 1 or 2, wherein the bearing element has a wall thickness that varies in the circumferential direction of its cross-section. A modular conveyor chain according to any one of the preceding claims, wherein the bearing element is flattened or open near a top facing the body part. Modular conveyor chain according to any one of the preceding claims, wherein the receiving space of the spaced coupling pieces each forms a substantially round hinge eye, and wherein the receiving space of the central coupling piece forms a substantially elongated hinge eye. Modular conveyor chain according to any one of the preceding claims, wherein the bearing element extends axially along the hinge pin and extends below the spaced coupling pieces. Modular conveyor chain according to one of the preceding claims, wherein the spaced-apart coupling pieces clamp onto the hinge pin via the bearing element. A modular conveyor chain according to any one of the preceding claims, wherein the bearing element on the outer jacket is provided with a stop. 9. Modular conveyor chain according to claim 8, wherein the stop comprises a radially outward back which extends axially along the outer casing of the bearing element, which is threaded between a free end of a coupling part and a body part. The modular conveyor chain according to claim 8, wherein the stop comprises a radially outward back that extends in a circumferential direction along the outer casing of the bearing element, which is threaded between adjacent sides of the central coupler and an spaced coupler. 11. Modular conveyor chain according to claim 8, wherein the stop comprises two spaced apart axially spaced, radially outwardly extending ridges, which extend circumferentially along the outer casing of the bearing element, each of which is located on either side of the central coupling piece. 12. Modular conveyor chain according to any one of the preceding claims, wherein the bearing element on the inner jacket comprises a stop. Modular conveyor chain according to claim 12, wherein the stop comprises a flange near an end of the bearing element that extends radially inwards from the casing. 14. Modular conveyor chain according to one of the preceding claims, 5, wherein the bearing element has an internal diameter which, in the non-assembled condition, is substandard with respect to the diameter of the hinge pin. A modular conveyor chain according to any one of the preceding claims, wherein the bearing element is provided on its jacket 10 expansion cut-outs. 2/4 3.4 FIG. 2C Si * τ 4/4 FIG. 5A 15.15a Title: Modular conveyor chain