GB2249073A - Propulsion unit for pallets in tile making machine - Google Patents

Abstract

The invention concerns a propulsion unit adapted for use in a concrete roof tile making machine, the said unit being capable of conveying tile pallets (P) of unit size and 1.05 unit size through the tile making machine. To this end the propulsion unit comprises chain mounted drive elements (60) which engage a cam track (96) provided with a curvilinear portion (100) connecting two linear portions (98, 102). Drive elements (60) engaging portion (98) are oriented out of engagement with the pallets (P), the curvilinear portion (100) causing the elements (60) to engage a pallet (P) of variable length, and the portion (102) maintaining engagement with the pallets (P). When the propulsion unit is in use, the conveyance of tile pallets (P) of e.g. 420mm to 432mm in length is facilitated without any modification, replacement and/or displacement of the propulsion unit or of any parts thereof. <IMAGE>

Description

IMPROVED PROPULSION UNIT This invention is concerned with improvements in or relating to a propulsion unit and is particularly concerned with improvements in a propulsion unit which is adapted for use in a concrete tile making machine.

Concrete tile making machines are well known and their use for producing roofing tiles or the like from cement, mortar or other cementitious compositions is well documented.

Such machines conventionally comprise conveyors for supporting tile pallets fed seriatim beneath material hoppers of a tile making section of the machine whereat concrete mortar is deposited on the tile pallets to form a continuous ribbon which is subsequently cut to form individual tiles on associated ones of said tile pallets. The tile pallets are normally fed seriatim beneath the hopper as aforesaid by a propulsion unit which may be of manifold forms.

However, the most conventional propulsion units comprise a pair of endless chains supported by associated sprockets in the tile making machine with drive elements carried by and between the chains and being arranged, when the tile making machine is in use, for engagement with trailing end portions of the tile pallets to feed them seriatim through the tile making section and beneath the hopper of the tile making machine as aforesaid.

One major drawback of propulsion units used hitherto is their inability to cater for tile pallets of different lengths without adjustment, replacement and/or displacement of complex parts of the unit.

Thus, in British Patent Specification 1447373 there is disclosed a propulsion unit having a pair of endless chains between which are supported six drive elements for engaging with an underside trailing end portion of associated tile pallets in order to feed the tile pallets beneath a hopper of the tile making machine. The propulsion unit of BPS 1447373 also comprises a downwardly inclined track the angle of inclination of which is said to be adjustable to cater for pallets of differing lengths. No details are given on the scope of pallet lengths which may be accommodated by such an arrangement and it is understood that only marginal differences in pallet lengths which result from pallet wear can be catered for by such an arrangement.

British Patent Specification 2139590 advocates that the drawbacks of earlier and more complex propulsion units may be overcome simply by replacing the endless chains and the track in order to cater for pallets of different lengths.

Such a proposal would seem to be a retrograde step in what is now usually a highly sophisticated piece of mechanism for tile making purposes.

British Patent Specification 2183209 discloses the use of at least two tracks which may be displaced laterally of the propulsion unit to enable the drive elements engaged thereby to cater for pallets of different lengths.

The prior art arrangements have not really addressed themselves to the problem of eliminating the change-over time necessary for enabling a tile making machine to cater for pallets of a first size, say 420 mm, followed by pallets of a second size, say 432 mm. Ideally, the change-over time should be zero; however, none of the prior art arrangements have this as their aim, nor do they come near to achieving such an aim.

The present invention seeks to overcome or at least mitigate the disadvantages of the prior art. Consequently, the present invention conveniently provides a propulsion unit adapted for use in a tile making machine as hereinbefore defined, said propulsion unit comprising an endless chain providing support for drive elements for successively engaging a series of tile pallets, when the tile making machine is in use, to convey them seriatim beneath a hopper of the tile making machine whereat tile making material is deposited on said pallets to form a ribbon of mortar thereon, the propulsion unit further comprising a track against which said drive elements are brought to bear to facilitate engagement thereof with the series of pallets as aforesaid, characterised in that, each track comprises first and second linear portions connected by a non-linear portion to facilitate, when the propulsion unit is in use, the conveyance of tile pallets of "unit length" and tile pallets of up to 1.05 "unit length", the arrangement being such that, when the propulsion unit is in use, engagement of the drive elements with said first linear portion orients the drive elements in a non-pallet engaging mode, engagement of the drive elements with said non-linear portion, when the propulsion unit is in use, facilitates the engagement of the drive elements with the series of pallets as aforesaid, and engagement of the drive elements with said second linear portion maintains the drive elements in a pallet engaging mode.

The non-linear portion of the track preferably comprises a downstream end portion whereat, when the propulsion unit is in use, the drive elements, as they successively come into engagement with said downstream end portion, are adapted to engage with associated ones of a series of tile pallets of unit length if they are in use to convey them seriatim beneath the hopper of a tile making machine as aforesaid, the non-linear portion of the track also comprising an upstream end portion whereat, when the propulsion unit is in use, the drive elements, as they successively come into engagement with said upstream end portion, are adapted to engage with associated ones of a series of tile pallets of 1.05 unit length if they are in use to convey them seriatim beneath the hopper of a tile making machine as aforesaid, the non-linear portion of the track also comprising an intermediate portion extending between said downstream and upstream end portions thereof between which, when the propulsion unit is in use, the drive elements as they successively come into engagement with said intermediate portion are adapted to engage with associated ones of a series of tile pallets of between unit length and 1.05 unit length if they are in use to convey them seriatim, beneath the hopper of a tile making machine as aforesaid.

Preferably the non-linear portion of the track is curvilinear, the first and second portions of the track are parallel one with the other or substantially so.

There now follows by way of example a detailed description of one embodiment of the invention, which description is to be read with reference to the accompanying drawings in which Figure 1 is a part side elevation of a tile making machine incorporating a propulsion unit provided by the invention; Figure 2 is an enlarged side elevation of the propul sion unit of Figure 1; Figure 3 is a section view along the line III-III of Figure 2; Figure 4 is a section view along the line IV- IV of Figure 2; Figure 5 is a fragmentary section view along the line V-V of Figure 2; Figure 6 is a fragmentary section view along the line VI-VI of Figure 2; and, Figure 7 is an enlarged fragmentary view of cam means shown in dotted line in Figures 1 and 2.

Propulsion units used hitherto have required modification, replacement and/or displacement in order to cater for the manufacture of concrete roofing tiles of different sizes.

However, the propulsion unit 2 provided by the present invention facilitates the manufacture of concrete roofing tiles of 420 mm to 432 mm in length without any modification, replacement and/or displacement of the unit or of any parts thereof.

To this end, the propulsion unit 2 see Figure 1 and 2, is not dissimilar to known units and comprises a support frame 4 which is readily mounted on a mainframe 5 of a tile making machine upstream of a tile making section 7 including a hopper 9 whereat cementitious composition is deposited onto tile pallets P fed thereto by said propulsion unit 2.

The support frame 4 comprises side walls 6 and 8 fixedly secured to form an open-edged box frame by left and right end walls 10 and 12 respectively, see Figure 2.

The walls 6 and 8 provided supports for bearings 14 and 16 respectively, see Figure 3, which bearings support a rotatable spindle 18 which in turn provides support for two spaced apart sprockets 20 and 22 keyed to the spindle 18 by keys 21 and 23 respectively. Drive for the spindle 18 is provided by a conventional motor (not shown) connected by a drive chain 24 to a sprocket 26 fixedly mounted on a splined right hand end 28 of the spindle 18, see Figure 3.

The walls 6 and 8 also provide support for housings 30 and 32 respectively, see Figure 4, which housings 30 and 32 support a fixed spindle 34 which in turn supports bearings 36 and 38 associated with spaced apart sprockets 40 and 42 respectively, see Figure 4.

The sprockets 20 and 22 are aligned with the sprockets 40 and 42 and provide support for a pair of endless chains 44 and 46 comprised of a series of links 48 and 50 respectively, said chains having upper operating runs 49 and lower return runs 51. Supported in known manner, between the chains 44 and 46 are five drive elements 60.

The drive elements 60 are of known configuration and are pivotally mounted on spindles 62, reduced end portions 64 and 66 of which are secured between associated ones of the links 50 and 48 respectively, see Figure 4.

The drive elements 60 each comprise a pair of drive dogs 68 arranged, when the propulsion unit is in use, to engage with trailing end portions of pallets P.

For controlling the engagement of the drive dogs 68 with the pallets P, the drive elements 60 each comprise a cam roll 70 and the propulsion unit 2 comprises cam means 72 provided by a platen 74 mounted between the walls 6 and 8 on spindles 76 and 78, for a purpose to be made clear hereinafter, see Figures 2, 5 and 6.

The platen 74 comprises a cam track 96, see Figure 7, comprising: (i) a first linear portion 98 engagement of the cam rolls 70 with which portion 98, when the tile making machine and thus the propulsion unit 2 is in use, orients the drive elements 60 in a non-pallet engaging mode, (ii) a curvilinear portion 100 downstream of the portion 98, i.e. to the left in Figure 1, 2 and 7, engagement of the cam rolls 70 with which portion 100, when the tile making machine and the propulsion unit 2 is in use, facilitates engagement of the drive dogs 68 with trailing end portions of the pallets P as aforesaid, and (iii) a second linear portion 102 downstream of said curvilinear portion 100, i.e. to the left in Figure 1, engagement of the cam rolls 70 with which portion 102, when the tile making machine and thus the propulsion unit 2 is in use, maintains the drive dogs 68 in pallet engaging modes as they pass therealong.

The curvilinear portion 100 of the track 96 comprises a downstream end portion 110, see Figure 7, whereat, when the tile making machine and thus the propulsion unit 2 is in use, the cam rolls 70 come into engagement therewith and, if tile pallets P of unit length are being used, the drive dogs 68 of said drive elements 60 engage with trailing end portions of associated pallets P.

The curvilinear portion 100 of the track 96 also comprises an upstream end portion 112, see Figure 7, whereat, when the tile making machine and thus the propulsion unit is in use, the cam rolls 70.come into engagement therewith and, if pallets P of 1.05 unit length are being used, the drive dogs 68 of said drive elements 60 engage with trailing end portions of associated pallets P.

The curvilinear portion 100 of the track 96 further comprises an intermediate portion 114 between said downstream and upstream end portions 110 and 112 respectively, whereat when tile making machines and thus the propulsion unit 2 is in use, the cam rolls 70 come into engagement therewith and if pallets P of between unit length and 1.05 unit length are being used, the drive dogs 68 of said drive elements engage with trailing end portions of associated pallets P.

The spindle 76, see Figure 5, comprises an eccentric midportion on which a left hand downstream end of the platen 74 is mounted the purpose of which eccentric mid-portion will be made clear hereinafter. The spindle 78, however, is a simple shaft which extends through the walls 6 and 8 to be secured thereto by bolts 80 and 82, see Figure 6.

Also mounted on bushes 75 and 77 of concentric portions of the spindle 76 and on the spindle 78 are control tracks 90 and 92, see Figures 1, 2, 5 and 6, the purpose of which control tracks, when the tile making machine and thus the propulsion unit are in use and the drive elements 60 are moving through the upper runs 49 of the chains 44 and 46, is to assist in the orientation of the drive elements 60.

To this end the drive elements 60 each comprise a pair of rolls 61 and 63 arranged to engage said tracks 90 and 92, see Figures 2 and 7.

It will be appreciated from the above that the novel propulsion unit enables tile pallets of "unit length" and tile pallets of greater than unit length to be conveyed to the making section 7 of a tile making machine without having to effect the modification, replacement and/or displacement of the propulsion units or parts thereof.

Slight wear of the pallets P is alleviated by rotation of the spindle 76 which alters the attitude of the track 96 and hence the positions at which successive drive elements 60 engage with associated pallets P while slight wear of the chains 44 and 46 may be alleviated by re-tensioning the chains using the conventional tensioning means 120 illustrated in Figures 1, 2 and 4.

Other modifications may be made within the scope of the present invention.

Claims (6)

1. A propulsion unit adapted for use in a tile making machine as hereinbefore defined, said propulsion unit comprising an endless chain providing support for drive elements for successively engaging a series of tile pallets, when the tile making machine is in use, to convey said tile pallets seriatim beneath a hopper of the tile making machine whereat tile making material is deposited on said pallets to form a ribbon of mortar thereon, the propulsion unit further comprising a track against which said drive elements are brought to bear to facilitate engagement thereof with the series of pallets as aforesaid, characterised in that, each track comprises first and second linear portions connected by a non-linear portion to facilitate, when the propulsion unit is in use, the conveyance of tile pallets of "unit length" and tile pallets of up to 1.05 "unit length", the arrangement being such that, when the propulsion unit is in use, engagement of the drive elements with said first linear portion orients the drive elements in a non-pallet engaging mode, engagement of the drive elements with said non-linear portion facilitates the engagement of the drive elements with the series of pallets as aforesaid, and engagement of the drive ele ments with said second linear portion maintains the drive elements in a pallet engaging mode.

2. A propulsion unit according to Claim 2 wherein the non-linear portion of the track comprises a downstream end portion whereat, when the propulsion unit is in use, the drive elements, as they successively come into engagement with said downstream end portion, are adapted to engage with associated ones of a series of tile pallets of unit length if they are in use to con vey them seriatim beneath the hopper of a tile making machine as aforesaid, the non-linear portion of the track also comprising an upstream end portion whereat, when the propulsion unit is in use, the drive elements, as they successively come into engagement with said upstream end portion, are adapted to engage with asso ciated ones of a series of tile pallets of 1.05 unit length if they are in use to convey them seriatim beneath the hopper of a tile making machine as afore said, the non-linear portion of the track also compris ing an intermediate portion extending between said downstream and upstream end portions thereof between which, when the propulsion unit is in use, the drive elements as they successively come into engagement with said intermediate portion are adapted to engage with associated ones of a series of tile pallets of between unit length and 1.05 unit length if they are in use to convey them seriatim, beneath the hopper of a tile making machine as aforesaid.

3. A propulsion unit according to either one of Claims 1 and 2 wherein the non-linear portion of the track is curvilinear or substantially so.

4. A propulsion unit according to any one of Claims 1, 2 and 3 wherein the first and second portions of the track are parallel one with the other or substantially so.

5. A propulsion unit substantially as hereinbefore de scribed with reference to the accompanying drawings.

6. A concrete tile making machine incorporating a propul sion unit as claimed in any one of the preceding Claims.