EP2917607A1

EP2917607A1 - High load conveyor chain and method

Info

Publication number: EP2917607A1
Application number: EP13852633.0A
Authority: EP
Inventors: Charles C. Frost
Original assignee: Frost Tech LLC
Current assignee: Frost Tech LLC
Priority date: 2012-11-07
Filing date: 2013-11-06
Publication date: 2015-09-16
Also published as: EP2917607A4

Abstract

An overhead conveyor, components therefor and method for making same, in which the conveyor chain has a nominal pitch "X," but a maximum allowable chain pull value which is equal to or greater than the maximum allowable chain pull value for a chain having a nominal pitch of X + 1. Trolleys can be attached to the chain at intervals which differ from the intervals of a chain with pitch of X + 1. Fewer synchronized drives are required for driving longer chains. A lower pitch chain can be used to drive larger trolleys, without sacrificing the maximum allowable chain pull value always used in conjunction with the larger trolley.

Description

HIGH LOAD CONVEYOR CHAIN AND METHOD

CLAIM OF PRIORITY

[0001] This application claims priority to United States Provisional Application Serial Number

61/723,482, filed November 7, 2012, entitled HIGH: LOAD CONVEYOR CHAIN AND METHOD, and to United States Patent Application Serial Number 14/073,201, filed November 6, 2013, entitled

HIGH LOAD CONVEYOR CHAIN AND METHOD,

FIELD AND BACKGROUND OF THE INVENTION

[0002] The presen invention relates to overhead conveyors, which typically comprise at least an. ui beam" track., trolleys which have opposed wheels engaging the bottom flanges of said I beam track on opposite sides of the center web of the beam., and a driven conveyor chain connected to said trolleys at spaced intervals. The chains usually comprise center links alternating with a pair of side links, which overlap the end of the center link on the opposite sides thereof, and are joined to the center link by a pin passing through the overlapping ends of the side links and center links.

[0003] In accordance with long standing industry practice, the links of said chains come in lengths giving them a nominal 2 inch, 3 inch, 4 inch or 6 inch pitch dimension. The pitch is the distance between the centers of adjacent pins, and is referred to as nominal, as the pitch is typically 1/16 of an inch more than the nominal number. The actual length of each chain link is long enough to provide for the overlap, and leave the nominal pitch dimension as indicated. Chains are Identified in part by their pitch. Thus a chain with a two Inch pitch is referred to as a 2 inch chain, and so on. B industry standard, a 2 Inch chain uses pins which are 2/8 (1 /4) Inch in diameter, and hence is referred to more specifically as an X .228 chain. A 3 inch chain uses pins which, are 4/8 (1 2) inch ui diameter, and is more specifically identified as an X 348 chain. These and other dimensions for 2, 3, 4 and 6 inch chains are set forth in Table 1 , with dimension "F" being the pin diameter. The other dimensions, A,. 8, C, etc listed in Table 1 are indicated in FIGS. 3 and 2. These are industry standards established through years of practice, and are^' set forth in the publications of the Conveyor Equipment Manufacturers Association (CEMA).

Chain A 8 C D E F G H Ϊ

" max max i-πίπ miri ITiiil

X-228 2 15 32 11/16 3/a M/8 1/4 53/64 1-1/ 6 S 18

X-50-β (SO) (11.90) (17.46) (9.53) (28.57) (6.35) ■(21.03) {26.98) {7,84)

X-34S 3 3/4 1-3/32 1/2 1-27 32 1/2 1-8/32 1-6/8 ¾ie

X-75-13 (75) {19.05} (27.78) (12.70) {46.83) (12.70) (32.54) {41.27) (14.28)

X-4S8 4 1 1-13/32 5/8 2-1/4 5/8 1-5 $ 2-1/4 1 /16

X- 00-16 (100) (25.4) (35.71) (15.87) (57.15) (15.87) (41.27) (57.15) 07.46)

X-678 6 1-8/32 2 3/ 6 3-118 7 2-1/* 3-3 S 31/32

X-150-22 (150) (32.80) (50.80) (20.63) ,78.37) (22.22) {57.13', (85.72) {24-61)

[0004] Trolleys are connected to the driven chains by a depending leg which passes through, the opening in a center link. Thus, trolleys can be spaced as close as nominally 4 inches for a two inch chain, or in multiples thereof. For a three inch chain, the spacing would be six inches or multiples thereof, for a four inch, eight inches or multiples and tor a six inch, 1.2 inches or multiples thereof.

[0005] Also by industry standards and practice, the pitch of the chain used matches the nominal height of the I beam track used. The height of the beam may be hi gher than its nominal value, e.g. the actual height of a 2 inch beam is 2 5/8 inches. Also by industry standard and practice, trolleys are referred to by their nominal wheel diameter, which corresponds to the .nominal height of the beam track they are carried on. The actual, diameter is slightly less than the actual height of the I beam, so there is no binding of the trolley wheel between the lower beam flange and the upper beam, flange. Thus a trolley with a nominal wheel diameter of 2 inches is used on a nominal 2 inch beam, a nominal 3 inch diameter wheel trolley is used on a nominal 3 inch beam, a 4 on a 4, and a 6 on a 6.

[0006] Further, chains made to the various pitches are by practice and Industry standard fashioned and manufactured to dimensions and pin sizes which cause the chain to have industry specified maxi um allowable "chain pall loads/" Chain pull load refers to the load placed on the chain as it pulls its associated trolleys and any loads they are carrying. Thus, a 3 nch chain has a maximum allowable chain pull load of 1500 pounds. For a 4 inch chain it is 3000 pounds, and for a six inch chain, 5500 pounds.

[00071 Trolleys are referred to by their nominal wheel diameter, which by industry- standard and practice corresponds to the nominal beam height. The drive chain is driven by one or more drives. Multiple drives must be synchronized, and are used to make sure the maximum chain pull load for the chain is not exceeded in any portion thereof.

SUMMARY OF THE INVENTION

[0008] The present invention comprises an overhead conveyor, components therefor and method for making same, in. which the conveyo chain has a nominal pitch "X," but a maximum allowable chain pull, value which is equal to or greater than the maximum allowable chain pull value for a chairs, having a nominal pitch of X+ 1.

[0009] hi a more preferred embodiment, the conveyor chain lias a pitch which is less than the nominal height of the beam on which it is carried, but has a maximum allowable chain pull, value which is equal to or greater than thai of a chain having a pitch equal to or greater than the height of the beam,

[0010] This invention facilitates hitherto unappreciated advantages. For one, trolleys can be attached to said chain at intervals which differ from the intervals of a chain with pitch corresponding to the nominal height of the team. Another is that fewer synchronized dr es are required for driving longer chains, Yet another is that a lower pitch chain can be used to drive larger trolleys, without sacrificing the maximum allowable chain pull value always used in conjunction with the larger trolley. Thus for example, a 2 inch chain can drive 3 inch trolleys, with the same maximum allowable chain pull value provided by a 3 inch chain.

BRIEF DESCRIPTION OF THE DRAWINGS

[001.1] FIG. 1 is a side elevational view of a chain segment identifying dimensions provided in

Table 1 ;

[00 ! 2] FIG. 2 is a top plan view of a chain segment identifying dimensions provided in Table 1. :

[0013] FIG. 3 is a side elevational view of a three inch beam carrying a three inch chain with trolleys spaced at six inches;

[0014] FIG. 4 is a side elevational vie of a three inch beam carrying a two Inch chain of strength, comparable, that of a three inch chain, with trolleys spaced at eight inches;

[0015] FIG. 5A is a side elevational view of the adjoining links and pin for a two inch chain having the strength of a three inch chain

[0016] FIG. SB is a side elevational view of the adjoining links and a pin for a conventional ^'two inch chain.

[0017] FIG.. 6A is a top plan view of the adjoining links of FIG. 5A; and

[0018] FIG. 6B is a top plan vie of the adjoining links of FIG. 513.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019] The present invention is illustrated in the preferred embodiment by comparing a prior art

3 inch chain .1 a driving 3 inch trolleys 20a o a 3 Inch beam 30a. (FIG. 3), to a 2 inch chain 10b driving 3 inch trolleys 20b on a 3 Inch beam 30a (FIG. 4). Each chain has center links I l a or 1 lb respectively, joined by pairs of side links 12a or 1.2b, The adjacent links are joined by pins 13a_. and 13b respectively. One of the advantages of the present invention is thai by using a 2 inch chain 10b with the strength of the 3 inch chain 10a or greater, one can achieve the same or greater maximum allowable chain put! load while giving the operator greater flexibility in trolley spacing. For the 3 inch chain shown in FIG. 3, art operator must space his trolleys at 6, 1.2, 1 , 24 inches, etc. in contrast, an operator using a 2 inch chain of the present invention enjoys the same maximum allowable chain pull load as the operator using a 3 inch chain, but can. space the trolleys 20b as close as 4 inches, or at multiples thereof. While a 6 inch spacing might be too close for the operator's proposed use, a 12 inch spacing may simply waste space, and require a higher chain speed to achieve the desired level of productivity. By using a 2 inch chain in accordance with the present invention, the operator can. use a spacing of 8 inches, rather than 6 inches, without sacrificing maximum, allowable chain pull toad, merel by securing a trolley to every other center link as shown in FIG. 4, The same level of productivity can be achieved using a proportionally lower chain speed.

[0020] in the preferred embodiment shown, the 2 inch chain 10b is given the strength of the 3 inch chain lOa byi

1. Utilizing a ½ inch pin instead of a ¾ inch pin, and

2. By utilizing 2 nch pitch links which are thicker in material cross section than those of a prior art^' 2 inch pitch chain.

[0021] See FIGS, 5A, SB, 6A and 6B. To reflect the difference in pin diameter, the preferred embodiment 2 inch chain iOb is identified more specifically as an X-248 chain, rather than as a prior art X-228 chain. The pins used in the 3 and 4 inch preferred embodiment chains would have -diameters of 5/8 and 7/8, and would be more specifically identified as X-3,58 and X 478 chains, rather than conventional X--34S and X-458.

[0022] The center links lib of the preferred embodiment 2 inch chain 30b have, spaced side legs

I4h with a height of -5 inch as compared to 0,3 inch for the leg portion 14c of a center link 1 le of prior art 2 inch chain 10c Preferably the center link. legs in aii of the preferred embodiment chains are 50-75% taller than their corresponding prior art counterparts, i.e. industry standard center links for chains of the same pitch, Similarly, the thickness of the leg portions b of center link 1 l b are .26 inch as compared to J 9 inch thickness for the legs 14c of a prior art 2 inch, chain iOc. Preferably, the center link legs in all of the preferred embodiment chains are 25- 50% thicker than their prior art industry standard counterparts. The corresponding dimensions for spaced legs 15b and 15c of the side links 12b and 12c are:

Heights .26 inch versus J 9 inch; and

Thicknesses .35 inch versus .25 inch.

[0023] Preferably the side link legs in all of the preferred embodiment chains are 25-50% taller, and 25-50% thicker than their corresponding prior art counterparts. Other measures can be taken to farther strengthen the 2 inch chain 10b of the preferred embodiment hi a similar manner, the dimensions of the links used in. the 3 and 4 inch chains of the preferred embodiment chains are larger in similar proportions than those of corresponding prior art 3 and 4 inch chains.

[0024] The trolleys 20a and 20b shown in FIGS. 3 and 4 have a pair of wheels 21 a and 21 b respectively, each wheel being oriented on an. opposite of its respective beam 30a A pair of amis 22a and 22b respectively extend, downwardly, one from each of the opposed wheels 21a or 21b. Arms 22a and. 22b respectively extend downwardly and then inwardly towards one another, and then downwardly again to define downwardly depending legs 25a and 25b. The legs 25a and .25b pass through the openings in the respective center links 1 .1a and l i b. A. downwardly depending, working attachment (not shown) may be secured between said legs 25. The working attachment might be a hook for hanging material to convey, or a pusher for pushing free trolleys on a lower track, or some oilier device.

[0025] Leg 25b of trolley 20b is slightly narrower than leg 25a of trolley 20a. This allows leg

25b to fit within the smaller opening of a 2 inch center [ink, as compared to the opening of the 3 inch center link 11a. Further while the arms and legs 22 and 25 of bom trolleys 20a and 20b both have ribs 23a or 23b rumiing along the respective edges thereof, trolley 20b includes an additional rib 24b extending between the two ribs 23b, located so as to be adjacent the top and bottom of the leg of center link l i b (compare FiG. 4 to FIG. 3). TMs gives greater strength to the narrower leg 25b of trolley 20b. No such joining rib 24 is used in the trolleys 20a.

[0026] The benefits of the present invention have not at all been recognized or thought of by prior artisans. The use of a 2 inch chain with the strength of a 3 inch chain or more gives an operator greater flexibility in spacing the troileys used, without sacrificing maximum, allowable chain pull load. The same is true for using a 3 inch chain instead of a 4, or a 4 instead of a 5. This not only maximizes chain capacity,, but also allows one to use slower chain speeds. If the trolleys and their loads have to be farther apart, the chain must move faster in order to meet production requirements. Closer spacing allows for slower chain speeds to meet the same production requirements. Using the chains at lower speeds causes less wear and tear on the chains, and avoids other problems as well. 100 to 130 feet, a minute is about as fast as the chains can be comfortably operated.

[0027] Another advantage is that the higher maximum chain pull value makes possible the use of fewer synchronized drives to drive the chain. Yet another is that a lower pitch chain can be used to drive larger trolleys, without sacrificing the maximum allowable chain pull value always used in conjunction with the larger trolley. Thus for example, a 2 inch chain cm drive 3 inch trolleys, with the same maximum allowable- chain pull value provided by a 3 inch chain.

These and other objects, advantages and features of the present invention will be understood and appreciated by those of ordinary skill in the art.

Claims

1. An overhead conveyor chain having a nominal pitch of "X" inches, with a .maximum allowable chain pull value which is equal to or greater than the maximum allowable chain pull value for a chain having a nominal pitch of X+ 1 inches.

2. The overhead conveyor chain of claim 1, having pairs of spaced side links joining alternating center links, in. which, said center links have spaced center link legs which are 50-75% taller in a direction perpendicular to the length of the chain, and 25-50% thicker, than the center link legs of industry standard chains having the same pitch.

3. The overhead conveyor chain of claim 2 in which said side links have spaced legs which are 2.5-50% taller in a direction perpendicular to the length of the chain, and 25-50% thicker, than, the side link legs of industry standard chains having the same pitch.

4. The overhead conveyor chain of claim. 2 which is a nominal 2 inch pitch chain, in which said side links and center links are joined by ½ inch diameter pins.

5. The overhead conveyor chain of claim 2 which is a nominal 3 inch pitch chain, in which said side links and said center links are joined by 5/8 inch diameter pins. - The overhead conveyor chain of claim 2 which is a nominal 4 inch pitch chain, in. which said side links and said, center links are joined by 7/8 inch, diameter pins.

3

7. The overhead conveyor chain of claim 1 which is a nominal 2 inch pitch chain, in which said side links and center links are joined by ½ inch diameter pins.

8. The overhead, conveyor chain of claim 1 which is a nominal 3 inch pitch chain, in which said side links and said center links are joined by 5/8 inch diameter pins.

9. The overhead conveyor chain of claim 1 which, is a nominal 4 inch pilch chain, in which said side links and said center links are joined by 7/8 inch diameter pins.

10. An overhead conveyor comprising: a driven conveyor chain having a nominal pitch of "X" inches; a beam track having a nominal height of X ÷ i inches;, trolleys having nominal. X + I inch wheel diameter riding on said track and attached to said driven, conveyor chain; and said driven conveyor chain having a. maximum, allowable chain pull value which is equal to or greater than, the maximum allowable chain pull value for a chain having a nominal pitch of X+ 1 inches.

I L ^'The overhead conveyor of claim 10 in which plural synchronized drives are used to drive said driven chain, the number used being that which, would be used for a driven chain of X + 1 inch nominal pitch having the same overall length of said driven chain.

1.2. The overhead conveyor of claim 1 1 in. which said chain is a nominal 2 inch chain, said beam and trolley are nominal 3 inch, and said, trolleys are connected to said chain at 8 inch intervals.

33. The overhead conveyor of claim 10, in which said chain has pairs of spaced side Links joining alternating center links, in which said center links have spaced center link legs which are 30-75% taller in a direction perpendicular to the length of the chain, and 25-50% thicker, than the center link legs of industry standard chains having the same pitch .

14. The overhead conveyor of claim 13 in which said side links have spaced legs which are 25-50% taller in a direction perpendicular to the length of the chain, and 25-50% thicker, than the side link legs of industry standard, chains having the same pitch.

15. The overhead conveyor of claim 12 in. which said chain is a. nominal 2 inch pitc chain, in which said side links and center links are joined by ½ inch diameter pins.

16. The overhead conveyor of claim 12 in wiiich said chain is a nominal 3 inch pitch chain, in which said side links and said, center links are joined by 5/8 inch diameter pins.

17. The overhead conveyor of claim 12 in which said chair! is a nominal 4 inch pitch chain, in which said side link and said center links are joined by 7/8 inch diameter pins.

18. The overhead conveyor of claim 10 in whic said chain is a nominal 2 inch pitch chain, in which said, side links and center links are joined by ½ inc diameter pins.

19. The overhead conveyor of claim 10 in which said chain is a nominal 3 inc pitch chain, in whic said, side links and said center links are joined by 5/8 inch diameter pins.

20. The overhead conveyor of claim 10 in which said chain is a nominal 4 inch pitch chain, In which said side links and said center links are joined by 7/8 Inch diameter pin.

21. A method of constructin an overhead conveyor comprising: providing a drivers, conveyor chain .having a nominal pitch, of "X" inches, having a maximum allowable chain pull value which is equal to or greater than the maximum allowable chain pull value for a chain having a nominal pitch of X+ 1 inches; providing a beam track having a nominal height of X 4 I inches; mounting trolleys having nominal X + 1 inch wheel diameter to ride on said track and attaching said trolleys to said driven conveyor chain.

22. The method of claim 21 in which plural synchronized drives are used to drive said driven chain, the number used being that which would be used for a driven chain of X 4-1 inch nominal pitch having the same overall length of said driven chain.

23. The method of claim 21 in which said chain is a nominal 2 inch chain, said beam and trolley are nominal 3 inch, aid said trolleys are connected to said chain at 8 Inch intervals.