The present invention relates to an apparatus according to the features of the precharacterising part of claim 1.
Until now, in order to detach the useful pieces obtained by casting from the risers, that is from those parts of the cast material which have solidified in the ducts through which the molten material is introduced into the moulds at the end of the casing and then to separate the pieces from the risers themselves, tumbling or rotary barrels or even vibratory machines have been used which generally work discontinuously. One of these machines is described in the German patent No. DE-C-435,166, granted on 24th December, 1925 in the name of Deutsche Machinenfabrik.
In known apparatus the detachment of the risers, runners and burrs from the useful pieces occurs due to the specific pressure of the useful pieces against each other and, when the operation is finished, the useful pieces and detached parts are conveyed onto sieving devices; in certain cases the useful pieces are separated manually since the risers, because of their particular irregular form and because of the friction which they present, do not slide easily in the sieving apparatus.
The object of the present invention is to provide automatically-operating apparatus for the knockdown and the immediate subsequent separation and removal of the useful pieces from the parts detached therefrom so as to achieve the detachment of the risers and other parts progressively and without jamming, even for useful pieces of complex form, devoid of smoothness, and hence without damage to the useful pieces themselves.
This object is achieved by an apparatus as set out above according to the features of the characterising part of claim 1. Modifications of the subject-matter of claim 1 are contained in the dependent claims 2 to 7.
The constructional and functional characteristics of the knockdown and separating apparatus according to the invention will be more clearly understood from the following detailed description of a preferred but non- exclusive embodiment, the description being made with reference to the appended drawings given purely by way of example, in which:
With reference to the drawings, the apparatus of the present invention is consti- . tuted by a support framework 1, of metal sections, at the top of which is located a frame 2, also of metal sections, arranged to support for rotation a barrel 3 with its axis horizontal. The frame 2 is pivotally mounted at 4 on two rear pillars of the support framework 1 and, at its opposite end, is fixed to the front pillars of the framework 1 so as to be adjustable by means of two rods or plates 5, each of which is provided with an elongate slot 6 and is pivotally connected at one end to the frame 2; in each slot 6 is inserted a screw-threaded bolt or the like 7, fixed to the front pillars of the framework 1, and arranged to allow the locking of the rods 5 at a desired position and hence to allow the achievement of different inclinations of the frame 2 (and hence also of the barrel 3) with respect to the horizontal plane.
The rotatable barrel 3 is cylindrical, in the form shown in the drawings, with a rear open end 8, to allow the loading of the pieces 4 for knockdown, and with the opposite end closed by a movable lid 9, mounted for axial movement away from the mouth of the barrel 3 by means, and for the reasons, which will be explained below. The barrel 3 is rotatably mounted on the inclinable frame 2 by means of pairs of driving rollers 10-11 (one pair on each longitudinal side of the frame 2); the rollers of each pair are connected to each other by a transmission shaft 12 and are mounted idly on support lugs 13-14 fixed to each longitudinal side of the frame 2. A motor 15 and a chain and gear transmission, generally indicated 16 in the drawings, are provided for rotating at least one pair of the rollers 10-11 whereby these latter rotate the barrel 3 by friction. The barrel may also have longitudinal raised ribs 17-18 etc. on its internal surface for the known function of improving and/or accelerating the detachment of the waste parts from the usable pieces.
The movable lid 9 is mounted for axial translational movement relative to the mouth of the barrel 3 by means of an actuator device 19, operated by compressed air or the like, slidably mounted on a box support body 20 by means of a guide plate 21.
The opening movements of the lid 9 are arrested by stops at distances which are predetermined in dependence on the shape or size of the pieces to be discharged separately from each other.
The lid 9 is constituted by a disc-shaped body 22 forming the sealing means for mating with the edge of the barrel 3, to which disc body is fixed a cylinder 23 of smaller diameter than that of the interior of the barrel and peripherally provided with ribs or longitudinal projections 24-25 etc., equidistant from each other and arranged to form separate passages between each pair of ribs and the internal edge of the mouth of the barrel, the passages being of substantially labyrinthine form and variable width according to the degree of opening of the lid 9.
Within the framework 1, beneath the discharge mouth of the barrel 3, is arranged a chute body 26, pivotally mounted on pins 27 supported by two opposite support plates 28. The chute 26 is made to oscillate about the pins 27 by a piston 27 operated by compressed air or hydraulically, which drives a crank 30 connected to a wall of the chute 26 or acts at the axis of rotation of the chute itself. Hence the piston 29 can make the chute 26 oscillate so as to lower one or other of its opposite discharge ends alternately and hence allow the discharge of the product coming from the barrel 3 in two different directions, specifically onto two separate chutes 31 and 32. The chute 31 has a sieve bottom 33, with two collecting ducts 34 and 35 the first of which allows the discharge of the waste products of smaller size and the other the remaining pieces.
The sieve chute 31 is provided with a vibratory drive 36 which, if required, can vibrate the sieve 31 to facilitate the sieving and separation of the products during their passage along the chute 31 itself.
The apparatus is provided with a loading device, constituted by a chute or scoop 37, connected in orientable or oscillating manner to a cross member 38 which is mounted for vertical movement along two opposite uprights 39-40 by means of end rollers guided within guide rails formed along the internal faces of the uprights 39-40. The raising and lowering of the chute 37 is achieved by means of a geared motor 41 with a pulley which drives a chain 42 connected to the cross member 38. The inclination of the chute, loaded with products, in correspondence with the open loading mouth of the barrel is achieved by suitable known means not shown. Finally, in order to facilitate the loading of the chute 37, a trap or pit 43 may be provided in the plane on which the apparatus rests and into which the chute can descend down to the level of the said plane.
The knockdown operation occurs, as stated above, by the impact of the bodies introduced into the barrel due to the rotation thereof and, as the pieces become detached, as a result of the inclination of the barrel 3, the pieces will tend to move towards the lower end of the barrel where, if the lid 9 is slightly removed, (Figure 2), the ribs 24-25 etc., will form, together with the lid, a sieve and allow the passage of the desired pieces only, retaining all the other pieces within the barrel. After a predetermined time, by means of a command given by a central control unit of known type (not shown), the movable lid will be opened completely (Figure 3) and simultaneously the piston 29 will make the oscillating chute 26 change its position so that the pieces remaining in the barrel (that is, the useful pieces) will be conveyed onto the other discharge chute.
More particularly, Figure 2 shows the apparatus with the lid 9 slightly open whereby the pieces are discharged onto the chute 32, while Figure 3 shows the position of discharge of the products of larger size by means of the chute 31, with the oscillating chute inclined towards the chute 31 itself.
When the pieces also require deburring, the operation is carried out as follows:
When a further separation of the pieces which leave with the cover slightly withdrawn (or even completely withdrawn) is required, the vibratory sieve 31 allows this separation to be effected.
The loading of the apparatus may also be made, as well as with the scoop 37, also by other means such as continuous belt conveyors, in which case it will be possible to feed two similar knockdown apparatuses alternately.
Clearly, numerous modifications and variants may be made to the embodiment of the invention described above without thereby departing from the scope of protection of the invention itself; thus for example, the barrel may be formed with a polygonal, oval or other cross section, the drive system for the oscillating chute may be achieved by other, analogous means and the lid may also be perfectly flat, hemi-spherical or differently shaped.