Note: Descriptions are shown in the official language in which they were submitted.
1 10gC~61.5
r ¦
i FIELD OF THE INVENTION
; 1 This invention relates to link chains and more particularly
2 to a transmission or con~eyor chain having no pivot pins
3 interconnecting adjacent links.
,., .' '.
BACKGROUND OF THE INVENTION
4 In the well known link chaln, such as a bicycle chain, ~
adjacent links are interconnected by means of pivot pins which
6 permit each link to be rotatable about the axis of the pin such
7 that the chain is movable on a sprocket around a curvéd path.
¦ While such chains have been employed for many years and are of
g ¦ extremely well known design and construction, the chains are
¦ subject to frictional wear by reason of relative movement between
11 ~ the links and pivot pins. The wear of conventional link chains
12 ¦ results in loosening of the couplings of the links and unwanted
13 play which can detract fr performance and efficiency. In
14 addition, relative rotational movement of conventional links -~
¦ about the!associated pivot pins can be encumbered by the
16 ¦ presence of dirt and debris at the pivot points.
I S~MARY OF THE INVENTION
~: I . , --- . . ,'.
17 1 In brief, the present invention provides a link chain in
18 I which the links are joined one to the other by flexible, ~ensile
19 strip members which rigidly interconnect the links aiong the axis
I of the chain, and accommodate relativè angular movement of eacb
~, .
-2~
. '. ~'
link with reqpect to adjacent links without need for pivot pins
and without frictional movement between adjacent links. A
flexible, thin strip member is secured along an edge thereof to
an end of a link, while the opposite edge of such strip is
secured to the confronting end of an adjacent link to provide a'
flexible and non-frictionally coupled link pair, the links of
each adjacent pair being relatively movable about a transverse
axis by flexure of the strip member. The strip members have
tensile strength sufficient to provide a chain of intended
strength while having sufficient flexiblity to accommodate
angular movement of the links. The novel chain can be employed
as a transmission chain or as a conveyor chain. For conveyor
applications, a plurality of links is usually arrayed side by
side to provide an intended width, the links being secured along
the width of the conveyor by the flexible strip members. For
transmission purposes, the chain can be of single link or
multiple link width.
DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
Fig. 1 is a cutaway pictorial view of a link chain
embodying the invention;
Fig. 2 is a cutaway elevation view of the embodiment
of Fig. l;
Fig. 3 is a plan view of the embodiment of Fig. l;
.
- .
. ~ - .
10~15
Fig. 4 is a pictorial view of an alternative embodi-
ment of the invention employing a sprocket tooth extending
across the width of the link chain; and
Fig. S is a pictorial view of a further embodiment of
the invention employing distinct sprocket teeth.
DETAILED DESCRIPTION OF THE INVENTION
A link chain constructed and operative according to the
invention is shown in Figs. 1 through 3, and includes a plurality
of elongated links 10, each connected end to end with like links
to provide a chain of predetermined length, and also laterally
coupled to other like links to provide a chain of intended width. -
Each link 10 includes first and second enlarged end portions 12
and 14, within which is secured for flexural vement a relatively
thin flexiblestrip member 16. In the illustrated embodiment,
strip member 16 includes enlarged edges 18 and 20 which are
cooperative with corresponding slots 22 in the end portions 12
and 14 of links 10 for anchoring of the strip member to the
associated links. Each link end portion includes an anchoring
slot 22 or other means for anchoring an edge of the strip member
to the associated link end. An outwardly flared opening 2g is
provided in each link end portion to define a space within which
the strip member 16 can bend or flex during movement of a link
with respect to the adjacent link as the chain travels a curved
path.
In the illustrated embodiment a plurality of links 10
are arranged and interconnected in side by side relationship to
~ . , .
105~(~615
1 ¦' provide a chain of intended width, and also interconnected end
2 li to end to provide a chain of intended length. A link end 14a
3 j, of link lOa is disposed adjacent to link end 12b of an adjacent
4 li link lOb, the end 14b of link lOb being adjacent end 12c of
' link lOc. Link end 12b is also disposed adjacent to end 14d of
6 i laterally adjacent link lOd. Link end 14b is also laterally
7 ¦1 adjacent to end 12e of link lOe. In like manner an array of
~ links are laterally and longitudinally coupled to provide a chain
g ¦ of desired size. The adjacent link ends are interconnected by
¦ a strip member 16. In the embodiment shown in Figs. 1 through 3
11 ¦ a strip member 16a interconnects adjacent link ends 14a, 12b,
12 ¦ 14d and 12f. A strip member 16b interconnects link ends 12c,
13 1 14b, 12e and 14f. The strip members 16 each include side -
14 i edges 18 and 20 and which are of enlarged cross-section and which
Ij serve to anchor the strip member to the associated link ends.
16 ¦, The strip member 16a is secured at edge 20 within the correspond-
17 ll ing anchoring slot 22 of link end 14a, while the opposite
18 ¦ edge 18 is secured within the corresponding anchoring slot of
19 I adjacent link end 12b. Similarly, the edge 20 of strip member
! 16a is retained within the anchoring slot of link end 14d w~ile
21 i' the anchoring slot of end 12f secures the edge 18 of strip
22 ! member 16a. It is seen that the strip member is secured to
adjacent link ends at opposite edges such that relative anguTar
24 movement of the adjacent links is provided by flexure of the
! strips along the width. The strip members are slidably inserted,
2~ i as shown in Fig. 3, into the associated anchoring grooves 22 of
27 ,- the link ends to couple an intended plurality of links for a
28 ¦' given cha n configuration.
l, _5_
1050615
1 In typical operation, the transmission or conveyor chain
2 1 is installed for movement through a closed path and is driven
3 1I by a sprocket while disposed at o.ne or more positions in the
4 ¦, travel path. During movement around a curve, the longitudinally
1! adjacent links 10 are angularly movable with respect to each othe~
6 1. by means of the flexural action of strip member 16. As seen in
7 ¦' Fig. 2, for example, angular movement o link lOa with respect
8 ¦, to link lOb is permitted by the flexing of strip member 16a which
9 ¦¦ is shown in engagement with the lower surface of opening 24. The
¦' configuration and dimensions of the flex space provided by open-
11 1, ing 24 is determined in accordance with the degree of angular
12 ¦, movement required between adjacent links of a particular chain.
13 lj It will be appreciated that the novel chain suffers no sliding
14 ¦~ or rotational frictional contact between adjacent links since no
1( pivot pins are employed, as in a conventional link chain.
16 1 Relative movement between adjacent links is provided solely by
17 ¦ flexure of the strip members interconnecting the links.
18 1. In the embodiments described above, the end portions 12 and
19 ~, 14 of the links 10 can be cooperative with a sprocket wheel for
2~ ll propulsion of the chain. The end portions can be suitably con-
21 1, figured in any well known sprocket tooth shape for intended
22 I mating with the sprocket wheel. The invention can be alternative
23 'j ly implemented as shown in Figs. 4 and.5 in which a sprocket
24 ~,, tooth structure is provided at the central portion of:links 10
l between the enlarged end portions of the.links. - .
26 Referring to Fig. 4, a sprocket tooth 30 is joined to
27 . links 32a and 32b at a position centrally disposed between the
28 ' end portions thereof and extending transversely to the longitu-
29 dinal axis of the lin~s. The tooth 30 can be integrally formed
. . .
-6-
``` 10~ffU~ 15
1 I with the associated links 32a and 32b or can be a separate
2 ! element bonded or otherwise affixed to the links. In this
3 ¦ embodiment of Fig. 4 the links are maintained in a transversely
4 I extending array by the tooth 30 extending along the width thereof,
I and thus chain sections are provided which can be interconnected
6 ¦ with cooperative sections to form a chain of intended length.
¦ In a further embodiment, illustrated in Fig. 5> each link
8 I includes a respective sprocket tooth. A sprocket tooth 32a is
9 ¦ provided centrally of link 32a while a tooth 34b is provided
¦ with link 32b. Each of the links 32 and associated sprocket ;
11 ¦ teeth 34 is a physically distinct eIement and thus a plurality ~
12 ¦ of links can be arrayed to provide a chain of intended width .b
13 ¦ and connected with like arrays of links to provide an intended ~
14 length. ;
¦ It is contemplated that the links and strip members can be :
16 I formed of various materials depending upon needed structural
17 ¦ requirements and it is also contemplated that the strip member
18 ¦ can be secured to the link ends by various means. Accordingly,
19 j it is no~ intended to limit the invention by what has been
¦ particularly shown and described except as indicated in the
21 ¦~ appendo claims. - ¦
,
.
.'
