US3866742A

US3866742A - Anti-kink and rollback device for elevating scrapers

Info

Publication number: US3866742A
Application number: US316049A
Authority: US
Inventors: Gary P Freese; Ronald E Sarff
Original assignee: Caterpillar Tractor Co
Current assignee: Caterpillar Inc
Priority date: 1972-12-18
Filing date: 1972-12-18
Publication date: 1975-02-18
Anticipated expiration: 1992-02-18

Abstract

An elevator mechanism for an elevating scraper includes a flight assembly consisting of flight members which are attached to a pair of driven chains at spaced locations by means of mounting brackets consisting of an L-shaped element and a ladle-shaped element fixed to a baseplate mounting each flight member. A pair of stop blocks mounted on each baseplate, each having parallel and angled surfaces for contacting flexing chain links to act as anti-kink means for limiting back-flexing of the chains as well as to prevent excessive rollback of the flights as they contact the material being loaded.

Description

I United States Patent 1191 Freese et a1.

[ Feb. 18, 1975 ANTI-KINK AND ROLLBACK DEVICE FOR ELEVATING SCRAPERS [75] Inventors: Gary P. Freese; Ronald E. Sarff,

both of Joliet, Ill.

[73] Assignee: Caterpillar Tractor Co., Peoria, 111.

[22} Filed: Dec. 18, 1972 [21] Appl. No.: 316,049

[52] US. Cl. 198/175 1 1111. c1. 865g 19/00 [58] Field of Search 198/175, 176, 168, 172, 198/173, 174; 74/245 c, 250 c [56] References Cited UNITED STATES PATENTS 573,988 12/1896 Levalley 198/172 3,378,133 4/1968 Anderson et a1. 198/175 FOREIGN PATENTS OR APPLICATIONS Switzerland 74/245 C Primary ExaminerEvon C. Blunk Assistant ExaminerDouglas D. Watts Attorney, Agent, or FirmPhillips, Moore, Weissenberger, Lempio & Strabala 57 ABSTRACT An elevator mechanism for an elevating scraper includes a flight assembly consisting of flight members which are attached to a pair of driven chains at spaced locations by means of mounting brackets consisting of an L-shaped element and a ladle-shaped element fixed to a baseplate mounting each flight member. A pair of stop blocks mounted on each baseplate, each having parallel and angled surfaces for contacting flexing chain links to act as anti-kink means for limiting backflexing of the chains as well as to prevent excessive rollback of the flights as they contact the material being loaded.

5 Claims, 5 Drawing Figures PATENTED @975 v 3868,7 12

sum 3. 0F 5 ANTI-KINK AND ROLLBACK DEVICE FOR ELEVATING SCRAPERS BACKGROUND OF THE INVENTION The instant invention relates to an improved construction of the chain and flight assembly in use in the elevator mechanism of an elevating scraper.

The chain and flight assembly of an elevating scraper is commonly provided with a certain amount of slack or looseness to accommodate the buildup of dirt and mud on the idlers and sprockets forming apart of the flight assembly that frequently occurs during a scraper loading operation. One of the problems engendered by such slack tolerance is that the slack in the chain permits the links to which the flights are connected to kink or roll back when the flights encounter the material being loaded. The slack tolerance also allows the unloaded side of the chain to sag or back-flex thus causing excessive bounce of the elevator chain when the flight attachment link contacts the bottom support roller. Both rollback and back-flexing of the chain results in an increase in the amount of rotation of the chain pins and bushings thus causing premature wear. Premature Wear on the bushings in turn leads to improper operation of the flight assmebly.

In US. Pat. No. 3,378,133 to Anderson et al, assigned to Applicants assignee, the device for limiting rollback is provided. However, this device does not limit back-flexing.

OBJECTS OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved chain and flight assembly capable of operation for an extended and economic period of time.

It is a further object of this invention to provide an improved chain and flight assembly which includes an anti-kink and rollback device for limiting back-flexing and rollback of the elevator chain.

BRIEF DESCRIPTION OF THE DRAWINGS More specific objects and advantages of the present invention will become apparent from the following description and drawings wherein:

FIG. 1 is a front elevation of an elevator mechanism of an elevating scraper with the parts excluded for ease of reference;

FIG. 2 is a schematic of the lower end portion of the elevator mechanism adjacent the cutting edge of a self- Ioading scraper shown in partial cross section;

FIG. 3 is a cross-sectional view ofa single flight taken along lines II-II of FIG. 4;

FIG. 4 is an enlarged view in partial cross section of a single flight bracket; and

FIG. 5 is an enlarged view of the lower end portion of the elevator mechanism shown in FIG. 2.

DETAILED DESCRIPTION Referring to FIG. 1, conveyor is pivotally mounted as at 11 and 12 to the

sidewalls

13 and 14 of an elevating scraper.

Spreader tubes

15 and 16 rigidly connect side rails 17 and 18 which rotatably support shaft 19 carrying

chain drive sprockets

20, 21. Cooperating with the two drive sprockets and with the

lower idlers

24, 25 and carrier rollers 26-29 are two chains 30 (FIG. 2) which, together with a series of transverse flight members, one of which is shown at 32, form the conveyor or elevator. For purposes of clarity, neither of the two chains 30 are shown in FIG. 1. In addition, only one flight assembly 31 is shown in FIG. 1. However, the locus of the path formed by the extremities of the series of flight assemblies as they are driven is shown by phantom line 33. I

The shaft and drive sprockets are powered to rotate the chains and flights in a clockwise fashion as viewed in FIG. 2 by means ofa hydraulic motor 22 and a gearreduction mechanism 23 in order to urge the dirt upwardly and rearwardly into the scraper bowl. Referring to FIG. 2, a portion of the single chain 30 is shown passing over lower idler 24 and carrier rollers 28 mounted on side rail 17. The chain comprises two parallel series of inner and outer overlapping

side bars

34 and 35, respectively, pivotally connected by chain pins 36 and lockedby cotter pins 37, as best seen in FIGS. 3-5. Each chain pin carries a roller bushing 38, concentrically disposed within a chain roller 39. Replacing each third successive outer side bar 35 along the length of the chain is a combination of an L-shaped'bracket 40 and a ladle-shaped bracket 41 which are affixed to a baseplate 45 forming part of flight member 32 of each flight assembly. Two pairs of spaced

stop blocks

42 and 43 are secured to each baseplate'in line with the inner side bars 34. Each stop block has an angled stop surface 44 and a flat stop surface 46 for a purpose to be hereinafter described. The angled stop surface of the stops is located on its supporting base plate to be approximately in line with a respective one of said' pins, as best seen in FIG. 3.

During operation of a conventional elevating scraper, the chain and flight assembly on the slack side can and does sag and back-flex between idler 24 and carrier roller 28, as shown in phantom at 49 in FIG. 2, and between

carrier rollers

26 and 28. In order to correct this problem and as best seen in FIG. 3,

stop blocks

42 and 43 on the inner surface of the baseplate 45 are provided having a flat stop surface 46 which contacts and limits flexing of the chain as shown.

Returning to FIG. 2, when the outermost tip 47 of each flight contacts brokenearth adjacent the bowl cutting edge 48, a moment arm is created causing rollback or counterclockwise movement of the flights about the trailing chain pin 3611, as best seen in FIG. 5. In order to counteract this, angled stop surface 44 is provided on the innercorners of

stop blocks

42, 43, which are provided to prevent excessive rollback of the flight. Each angled stop surface should be positioned so as to contact and further limit rotational movement of a respective link when in the maximum rollback position as shown in FIG. 5. Obviously, the degree of rollback desired controls the stop surface angle and can be found experimentally.

It is to be understood that the foregoing description is merely illustrative of the preferred embodiment of the invention and that the scope of the invention is not to be limited thereto, but is to be determined by the scope of the appended claims.

What is claimed is:

1. In a chain and flight assembly consisting'of a plurality of flight members and a plurality of chains, at least one flight member extending between the chains, said flight member pivotally associated through link pins with a plurality of chain links, said chains comprising two parallel series of inner and outer overlapping side bars pivotally connected by said pins, and further including means for limiting rollback as well as backflexing of the chain, said last named means comprising two pairs of stops mounted on said at least one flight member, each of said stops including a first stop surface thereon positioned so as to contact associated chain links and thereby limit back-flexing of the chain,

a second stop surface thereon positioned so as to contact associated chain links and thereby limit rollback of the chain, and wherein said second stop surface is angled with respect to said first stop surface, and wherein each flight member comprises a baseplate and wherein said stops are located thereon with two pairs of spaced stops secured to each baseplate in line with the inner side bars so as to be adapted to be in contacting relation therewith and thereby limit rollback as well as back-flexing f the chain.

2. The invention of claim 1 wherein each third successive outer side bar of said chain along its length comprises an L-shaped bracket and a ladle-shaped bracket affixed to a respective baseplate forming a part of a flight member of the respective flight assembly.

3. The invention of claim 2 wherein each chain pin carries a chain roller concentrically disposed within a chain roller.

4. The invention of claim 1 wherein each stop comprises a generally rectangular stop block having a flat surface generally parallel to the plane of said baseplate and said angled surface forming an angle with respect to said flat surface and wherein said pairsof stops are oriented in facing relation on a respective baseplate so that the angled surfaces thereon are in facing relation, one to the other. Y

5. The invention of claim 4 wherein each angled surface of said stops is located on its supporting baseplate to be approximately in line with a respective one of said pins.

Claims

1. In a chain and flight assembly consisting of a plurality of flight members and a plurality of chains, at least one flight member extending between the chains, said flight member pivotally associated through link pins with a plurality of chain links, said chains comprising two parallel series of inner and outer overlapping side bars pivotally connected by said pins, and further including means for limiting rollback as well as backflexing of the chain, said last named means comprising two pairs of stops mounted on said at least one flight member, each of said stops including a first stop surface thereon positioned so as to contact associated chain links and thereby limit back-flexing of the Chain, a second stop surface thereon positioned so as to contact associated chain links and thereby limit rollback of the chain, and wherein said second stop surface is angled with respect to said first stop surface, and wherein each flight member comprises a baseplate and wherein said stops are located thereon with two pairs of spaced stops secured to each baseplate in line with the inner side bars so as to be adapted to be in contacting relation therewith and thereby limit rollback as well as back-flexing of the chain.

4. The invention of claim 1 wherein each stop comprises a generally rectangular stop block having a flat surface generally parallel to the plane of said baseplate and said angled surface forming an angle with respect to said flat surface and wherein said pairs of stops are oriented in facing relation on a respective baseplate so that the angled surfaces thereon are in facing relation, one to the other.