US3677686A

US3677686A - Apparatus for advancing pallets for making tiles

Info

Publication number: US3677686A
Application number: US833632A
Authority: US
Inventors: William Sydney Powel
Original assignee: Redland Tiles Ltd
Current assignee: Redland Tiles Ltd
Priority date: 1968-10-10
Filing date: 1969-06-16
Publication date: 1972-07-18
Anticipated expiration: 1989-07-18
Also published as: GB1278271A; FR2020274B1; ES368199A1; DE1929440A1; DE1929440B2; FR2020274A1

Abstract

Apparatus for feeding relative to a molding machine a continuous stream of pallets arranged end-to-end, characterized by the provision of pallet drive means including endless conveyor means upon which are pivotally connected a series of spaced driving elements each of which includes a nose portion for engaging an appropriate rearwardly directed face on the pallets, and a follower portion adapted for engagement by stationary cam track means. The cam track means includes an inclined first portion that converges at an acute angle toward the horizontal axis of the upper run of the conveyor means, and a second portion that is generally parallel with said axis. When the follower portion of a given drive element engages the first track portion, the drive member is pivoted from a retracted position forwardly relative to the conveyor means to drive the pallets at a speed greater than that of said conveyor means. When the follower portion engages the second track portion, the drive element travels at the speed of the conveyor means, and consequently the faster travelling pallets-which are now driven by a subsequent drive element whose follower portion is in engagement with the first track portionprogress out of engagement with the nose portion of said given drive element.

Description

United States Patent [15] 3,677,686 Powel [45] July 18, 1972 APPARATUS FOR ADVANCING Primary Examiner--J. Spencer Overholser PALLETS FOR MAKING TILES Assistant Examiner-Norman E. Lehrer Att0rneyLawrence E. Laubscher [72] Inventor: William Sydney Powel, Leatherhead, Sury England 57 ABSTRACT Assigneei Redlafld Tiles Limited, Reigate, y Apparatus for feeding relative to a molding machine a con- England tinuous stream of pallets arranged end-to-end, characterized [22] Filed: June 16 969 by the provision of pallet drive means including endless con- Appl. No.: 833,632

veyor means upon which are pivotally connected a series of spaced driving elements each of which includes a nose portion for engaging an appropriate rearwardly directed face on the pallets, and a follower portion adapted for engagement by stationary cam track means. The cam track means includes an inclined first portion that converges at an acute angle toward the horizontal axis of the upper run of the conveyor means, and a second portion that is generally parallel with said axis. When the follower portion of a given drive element engages the first track portion, the drive member is pivoted from a retracted position forwardly relative to the conveyor means to drive the pallets at a speed greater than that of said conveyor means. When the follower portion engages the second track portion, the drive element travels at the speed of the conveyor means, and consequently the faster travelling pallets-which are now driven by a subsequent drive element whose follower portion is in engagement with the first track portion-progress out of engagement with the nose portion of said given drive element.

7 Claims, 7 Drawing Figures Patented July 18, 1972 5 Sheets-Sheet 1 Po I INVENTOR ATTORNEY Patented July 18, 1972 5 Sheets-Sheet z w m 5, Fowel INVENTOR ATTORNEY Patented July 18, 1972 5 Sheets-Sheet 5 FIGS.

INVENTOR Patented July 18, 1972 3,677,686

5 Sheets-Sheet 4 Had W (l M I INVENTOR ATTORNEY Patented July 18, 1972 5 Sheets Sheet 5 walla mg INVENTOR APPARATUS FOR ADVANCING PALLEPS FOR MAKING TILES This invention is concerned with improvements in and relating to machinery for making tiles, slabs, bricks, blocks, cable covers and like products from such materials as cement, plastics, bituminous and asphalt mixes of various compositions. Hereinafter all such products will be referred to simply as tiles.

Various machines have been proposed for making tiles in which pallets, defining the underface of the tile, are fed in an end-to-end stream below a hopper containing a concrete mix where the stream receives mix which is metered and shaped by a shaping element such as a roller to form on the pallets a molded ribbon having an under surface shaped to the shape of the top surface of the pallets and a top surface to the shape of the element. The continuous ribbon of mix so formed on the base provided by the end-to-end pallets is cut at each pair of adjacent pallet ends to form individual pallet-borne elements which are thereafter racked and the mix cured on the pallets. The cured tiles are then removed from the pallets which are returned for reloading.

The stream or column of pallets may be formed from a magazine in which the pallets are stacked and from which they are withdrawn one-by-one and driven through the hopper or the pallets may arrive on a conveyor at the entry end of the machine and form an end-to-end stream at the inlet to the hopper below which they are driven by a feeding mechanism.

The feed mechanism which will take up the pallets and drive them below the hopper may comprise a pair of reciprocating fingers of which one is engaging and driving forward a pallet while the other is returning from a drive stroke. Alternatively a number of fingers are angularly spaced about a rotatable drive member so that each successively arrives at a point where it engages a pallet and drives it forward during a certain angular travel and then disengages whereupon the succeeding finger takes the next pallet. In either case each pallet as it is driven forward by the feeding mechanism engages the last driven pallet and all the pallets before that and urges the stream forward. However, the resultant motion of the stream is of non-uniform speed and may include a positive dwell as each finger disengages and the next takes up the drive. This is a disadvantage in that power is required to accelerate the stream of pallets and throughput is not equal to the maximum pallet speed achieved.

The object of the present invention is to provide a substantially constant speed molding machine and according to this invention there is provided a molding machine comprising a pallet support extending beneath a hopper for material to be molded and beneath a shaping element defining the transverse shape of one surface of articles to be molded, and means for advancing a stream of end-to-end pallets along the support which pallets will each present a rearwardly directed face, the advancing means comprising a endless driving member having a driving run adjacent the support, a plurality of driving elements pivotally mounted in the driving member, each driving element including a pallet face engaging nose and a follower, movement of which in one sense relative to the driving member will advance the associated nose relative to the driving member, and a track positioned adjacent the driving run of the driving element and in the path of followers of driving ele ments in that run, those followers engaging the track, moving thereon relative to the driving run and advancing the associated noses relative to the driving member into engagement with a pallet face and thereby into driving engagement with the stream, the track permitting movement of each follower in the sense opposite to the first sense when the following driving element nose has made driving engagement with the stream.

Further objects and advantages of the invention will appear from the following description of one embodiment, given by way of example only,. reference being had to the accompanying drawings in which:

FIG. 1 is a side elevation of a tile forming machine;

FIG. 2 is a detail view of the pallet feeding mechanism;

FIG. 3 is a front view of the feeding mechanism;

FIG. 4 is a part sectioned detail view of a driving element;

FIG. 5 is a part sectioned front elevation of the cutting mechanism;

FIG. 6 is a part sectioned side elevation of the cutting mechanism, and 1 FIG. 7 is an elevation showing the cutter drive.

The machine comprises a main frame 1, having a pair of hardened tracks or inserts 2 to receive pallets 3, a feeding mechanism including a pair of driving chains 4 with driving elements 5 mounted therebetween, a hopper 6 for the mix and a cutter mechanism 7. A suitable drive motor 8 is provided to drive a paddle shaft 9 in the hopper and a doctor/shaping roll 10 at the exit from the hopper and a motor 1 1 for driving the feeding mechanism and cutter mechanism as will appear.

Referring to FIGS. 2 and 3 each of the driving chains 4 of the feeding mechanism extends about a drive sprocket l2 and an idler sprocket 13 mounted respectively on a drive shaft 12a and idler shaft 13a mounted in the main frame. Extending between the chains are the driving elements 5 each of which is mounted on a spindle 15 carried in a pair of bearings 16. Each bearing 16 is set in a block 17 secured to one of the chains by a pair of bolts substituted for a pair of adjacent chain link pins. Each driving element 5 has a pair of noses 18 and a follower 19 formed by a roller, a secondary follower 20 being provided co-axial with follower l9. Mounted between the upper runs of the chains and in the path of the followers 19 when moving along the upper run is a track 21 having a first portion 280 of which is upwardly inclined in the direction of travel of the upper runs and of the pallets through the machine. Between the lower runs of the chains and in the path of the secondary followers 20 when moving along the lower run is a side guide 22 while adjacent the paths of the chains around the driving and driven spindles are guideways 23.

The pallets arrive at the machine by way of a conveyor 25 which is run slightly faster than the feed mechanism so that pallets 3 are delivered on to the tracks 2 where they accumulate since in the absence of the feeding drive the conveyor cannot push accumulated pallets through the hopper. A row of end-to-end pallets therefore extends over the outermost end at least of the feeding mechanism chain run, each pallet having a like positioned shoulder 27 on the underfacev When the drive shaft is turning a driving element 5 will rise up around the idler shaft and as the element travels along the upper run the follower 19 engages the inclined first portion 28a of the track 21. At the moment of engagement the element is in a first angular position about the axis of its spindle 15 but as the follower moves forward it is raised by the track and the noses are caused to advance more quickly than the chains until the follower reaches a second portion 28b of the track parallel to the chain upper run. During engagement with the second track portion 28b the attitude of the element is constant (i.e., the driving element is maintained at a second angular position relative to the chain) and the speed of the noses of the element is reduced to chain speed. The driving elements are so spaced along the chain and the track so angled that as the noses of one element achieve chain speed, the noses of the succeeding element have moved up to a shoulder on the second pallet thereafter to take up the drive. As soon as a follower 19 reaches the end portion 28c of the track, the element tilm back, thereby disengaging from the pallet which it has driven. Thus the forward speed of the pallets will be kept at a substantially constant velocity (namely, the forward speed of the element noses as the followers ride up the track). It is apparent, therefore that the column of end-to-end pallets is driven at a higher speed than that of said chain only by those driving elements that are being pivoted. relative to the chain by the inclined track portion 28a. The nose portions of the remaining driving elements which are not being pivoted relative to the chain have, of course, the same velocity as that of the chain, and consequently these elements have no driving effect on the faster traveling pallet column.

The noses are preferably rounded "to reduce wear as the noses change attitude while in contact with the shoulders.

The lower guide 22 engages the followers 19 and keeps the driving elements in the correct attitude (i.e. in the aforemem tioned pallet-engaging first angular position relative to the chain) while guideways 23 engage the secondary followers 20 to the same end.

To cut the ribbon of mix which passes out of the hopper between the pallets and the shaping roller 10, a cutter frame 30 is mounted on slides 31 on the main frame. Pivotally supported on cutter frame 30 are two knife guides 32 in each of which is a knife 33, carrying pins 34. Each knife is operable by a pneumatic cylinder 36. A dependent bracket 37 on the cutter frame is connected by a rod 38 to a crank 39 coupled to a shaft 40 driven by the feeding mechanism. A timing switch 41 is provided responsive to a cam 42 on shaft 41 to operate valves supplying air to cylinders 36. The operation of the cutting mechanism comprises reciprocation of the cutter frame by the crank to move the frame in the same direction as the loaded pallets and at the same speed, to actuate the knives whilst the frame is travelling at that speed and to reverse the frame to the start position.

Additionally to the cutting frame other mechanisms could be coupled to the drive or to the frame to carry out other operations on the tiles in exact timed relation to the feed mechanism, such as marking, forming or removing material from the top surface.

Advantages of the machine described are that the pallet speed is constant, a low tenacity mix can be used and a throughput in excess of 80 pallets a minute can be achieved.

I claim:

' 1. A molding machine feeding mechanism for advancing at a substantially uniform speed a colurrm of pallets arranged end-to-end, comprising a. a pallet support (2);

b. a column of pallets (3) arranged end-toend on said support, each said pallet having a rearwardly directed face c. means for advancing said pallet column along said support, comprising 1. conveyor means (4) having a generally linear driving run adjacent said support, said conveyor means being continuously driven at a given conveyor velocity;

2. a plurality of circumferentially spaced driving elements pivotally connected with said conveyor means, each of said driving elements having a nose portion (18) for engaging the rearwardly directed face of a corresponding pallet, and a follower portion (19); and

3. stationary track means (21) for pivoting said driving elements relative to said conveyor means during successive travel along said driving conveyor run to drive said column of pallets at a higher velocity than said conveyor velocity, said track means including a first track portion (28a) inclined at an acute converging angle relative to said conveyor driving run for engagement by said follower portions to pivot each successive driving element from a first pallet-engaging angular position forwardly in the pallet-driving direction relative to said conveyor means.

2. Apparatus as defined in claim 1, wherein each of said driving elements comprises a bell crank the intermediate portion of which is pivotally connected with said endless conveyor means, said nose and follower portions being arranged at opposite ends of said bell crank; and further wherein said track means includes a second track portion (28b) arranged downwardly in the direction of travel of said conveyor means from said first track portion, said second track portion being generally parallel with said conveyor driving run and arranged for engagement by said followers to maintain each successive driving element at a given second position relative to said conveyor means, whereby the corresponding rearwardly directed face of the faster traveling pallet column progresses out of driven engagement from the nose portion of said driving element when said driving element is in said second position.

3. Apparatus as defined in claim 2, wherein each of said driving elements is normally biased rearwardly in the direction from said second position toward said first position, and further wherein said track means includes a third portion (28c) arranged downwardly in the direction of travel of said conveyor means from said second track portion, said third track portion being inclined at a divergent acute angle relative to said conveyor driving run to permit return of successive driving elements from said second position toward said first position.

4. Apparatus as defined in claim 1, and further including guide means (22, 23) for maintaining said driving elements in said pallet-engaging first position during travel along the idle run of said conveyor means and along the end run toward said driving conveyor run.

5. Apparatus as defined in claim 1, wherein said conveyor means comprises a pair of pin and link chains, each of said driving elements being supported between said chains by a pair of bearings each carried by a bearing support mounted on a pair of adjacent chain pins.

6. Apparatus for conveying relative to a tile machine or the like a column of continuously supplied pallets arranged contiguously end-to-end on a fixed support, comprising a. continuously driven endless conveyor means (4) having a driving run of constant length and constant linear velocity extending longitudinally of and generally parallel with said support; b. a plurality of driving elements (5) pivotally connected with and circumferentially spaced about said endless conveyor means, each of said driving elements including a pallet-engaging nose portion 18) and a follower portion l9); and c. cam track means (21) for successively pivoting said driving elements relative to said conveyor means to drive said pallet column at a higher linear velocity than that of said conveyor means, said cam track means including 1. a first track portion (28a) arranged adjacent said conveyor first run for successive engagement by said follower portions to pivot each of said driving elements from a first pallet-engaging position forwardly in the pallet driving direction relative to said conveyor means toward a second position; and

2. a second track portion (28b) subsequently engageable by said follower portions and generally parallel with said conveyor driving run for maintaining said successive driving elements in said second position relative to said conveyor means for a given period of time, whereby the faster traveling pallets will be progressively displaced longitudinally away from the nose portion of a given driving element, when in the second position, by a subsequent driving element the follower portion of which is in engagement with said first track portion.

7. Apparatus for conveying relative to a tile machine or the like a column of continuously supplied pallets arranged contiguously end-to-end on a fixed support, comprising a. continuously driven endless conveyor means (4) having a driving run of constant length and constant linear velocity extending longitudinally of and generally parallel with said support;

b. a plurality of driving elements (5) pivotally connected with and circumferentially spaced about said endless conveyor means, each of said driving elements including a pallet-engaging nose portion (18) and a follower portion 19); and

c. cam track means (21) for successively pivoting said driving elements relative to said conveyor means to drive said pallet column at a higher linear velocity than that of said conveyor means, said cam track means being adjacent and angularly arranged at an acute convergent angle relative to conveyor driving run for engagement by said follower portions to successively pivot each of said driving elements from a first pallet-engaging position forwardly in the pallet driving direction relative to said conveyor means toward a second position.

Claims

1. A molding machine feeding mechanism for advancing at a substantially uniform speed a column of pallets arranged end-toend, comprising a. a pallet support (2); b. a column of pallets (3) arranged end-to-end on said support, each said pallet having a rearwardly directed face (27); c. means for advancing said pallet column along said support, comprising 1. conveyor means (4) having a generally linear driving run adjacent said support, said conveyor means being continuously driven at a given conveyor velocity; 2. a plurality of circumferentially spaced driving elements (5) pivotally connected with said conveyor means, each of said driving elements having a nose portion (18) for engaging the rearwardly directed face of a corresponding pallet, and a follower portion (19); and 3. stationary track means (21) for pivoting said driving elements relative to said conveyor means during successive travel along said driving conveyor run to drive said column of pallets at a higher velocity than said conveyor velocity, said track means including a first track portion (28a) inclined at an acute converging angle relative to said conveyor driving run for engagement by said follower portions to pivot each successive driving element from a first pallet-engaging angular position forwardly in the pallet-driving direction relative to said conveyor means.

2. a plurality of circumferentially spaced driving elements (5) pivotally connected with said conveyor means, each of said driving elements having a nose portion (18) for engaging the rearwardly directed face of a corresponding pallet, and a follower portion (19); and

6. Apparatus for conveying relative to a tile machine or the like a column of continuously supplied pallets arranged contiguously end-to-end on a fixed support, comprising a. continuously driven endless conveyor means (4) having a driving run of constant length and constant linear velocity extending longitudinally of and generally parallel with said support; b. a plurality of driving elements (5) pivotally connected with and circumferentially spaced about said endless conveyor means, each of said driving elements including a pallet-engaging nose portion (18) and a follower portiOn (19); and c. cam track means (21) for successively pivoting said driving elements relative to said conveyor means to drive said pallet column at a higher linear velocity than that of said conveyor means, said cam track means including

7. Apparatus for conveying relative to a tile machine or the like a column of continuously supplied pallets arranged contiguously end-to-end on a fixed support, comprising a. continuously driven endless conveyor means (4) having a driving run of constant length and constant linear velocity extending longitudinally of and generally parallel with said support; b. a plurality of driving elements (5) pivotally connected with and circumferentially spaced about said endless conveyor means, each of said driving elements including a pallet-engaging nose portion (18) and a follower portion (19); and c. cam track means (21) for successively pivoting said driving elements relative to said conveyor means to drive said pallet column at a higher linear velocity than that of said conveyor means, said cam track means being adjacent and angularly arranged at an acute convergent angle relative to conveyor driving run for engagement by said follower portions to successively pivot each of said driving elements from a first pallet-engaging position forwardly in the pallet driving direction relative to said conveyor means toward a second position.