Agitator, particularly for machine for making ice-cream or the like

Abstract: The invention relates to an agitator, particularly for machines for making ice-cream, or similar, and of the type comprising a plurality of radial paddle blades (3) which are supported at equal angular intervals by a rotary drive shaft (1). In order to produce a more economically manufactured agitator with lower weight and greater ease of handling, the invention proposes an agitator of sectional construction, whose individual elements consist of a rotary drive shaft section (1), a plurality of paddle blades (3) fixable by their axial ends to the shaft section (1) and a hub (4) connecting the paddle blades (3) together at their ends opposite the shaft section (1). The paddle blades (3) are made entirely of plastic material and constitute the greater part of the agitator.

Description: The invention relates to an agitator, particularly for machines for making ice cream, or similar, and of the type comprising a plurality of radial paddle blades which are supported at equal angular intervals by a rotary drive shaft. From EP-A- 0 386 323 a stirrer for ice cream making machines is known comprising a plurality of paddles constructed as helical fins, arranged radially and equally spaced apart angularly, connected to each other at their ends, respectively by means of a hub provided with a number of radial arms corresponding to the number of paddles of the stirrer, and having co-axially secured thereto a shaft section provided with a similar hub also provided with a corresponding number of radial arms. From US-A-1 685 189 an ice cream freezer is known comprising a cylinder having end heads and a rotary dasher assembly longitudinally arranged within said cylinder, said assembly including longitudinal pivotally hung scrapers, which are accesible, removable and insertable through the front ends of the freezer. The object of the invention is to provide an agitator of the aforesaid type, which may obviate to the drawbacks of the referred prior art agitators, which is of lower manufacturing costs, which will provide a considerable decrease in weight and consequent greater ease of handling, without in any way compromising the functional quality of the ice cream being worked. According to one aspect of the invention the above object is achieved by providing an agitator for ice-cream making machines of the type comprising a plurality of radial paddle blades which are connected by their opposite ends at equal angular intervals to the free ends of radial arms secured to a rotary drive shaft section and to a connecting hub coaxial with the said drive shaft section, in which the said paddle blades are made of plastics material and in which the radial extension of the paddle blades is considerably larger than, and more than twice as great as, the radial extension of the said supporting arms. From half to two thirds of the total radial extension of the agitator is constituted by the radial extension of the paddle blades. The above description clearly demonstrates the constructional simplicity of the agitator according to the invention and its great economy. The fact that paddle blades of plastic material are specified and that these constitute the greater part of the agitator contributes to the achievement of a reduction of weight and greater ease of handling. The invention also relates to other characteristics which further improve the agitator described above and which form the subject of the subsidiary claims. The characteristics of the invention and the advantages derived therefrom will be clearly understood from the description of a preferred embodiment, illustrated by way of example and non-restrictively in the attached drawings, in which Fig. 1 shows a side view, partially in section, of half of an agitator according to the invention; and Fig. 2 is a view in the axial direction of the complete agitator according to the invention. With reference to the figures, an agitator according to the invention comprises a drive shaft section 1 which carries at one end three short arms 2 distributed at equal angular intervals, a paddle blade 3 fixed to each arm 2 at one of its axial ends, and a hub 4 connecting the paddle blades 3 together at the axial end opposite the shaft section 1. The paddle blades 3 are formed from plates of plastic material which are orientated substantially radially with respect to the axis of the drive shaft section 1 and which have a helical development. The connecting hub 4 also has three fixing arms 2' for the paddle blades 3. The plates which form the paddle blades 3 are fixed by their radially inner sides 103 to the radially outer ends 102, 102' of the arms 2, 2'. Fixing is provided by radial bolts 5 which are enclosed within the thickness of the plates forming the blades 3 and whose heads are accessible through enlarged radial cavities 6. The cavities are open on the radially outer side of the plates and may be sealed with plugs of plastic material 7 which may be inserted by forcing, for example. The bolts 5 may be screwed into threaded radial holes 8 in the arms 2, 2'. On their facing contact ends 102, 102' and 103, the blades 3 and the arms 2, 2' have coinciding radial centring holes 9, 10 respectively in which centring pins 11 may be housed. The radially outer working sides of the paddle blades 3 have radial recesses 12 in which scraper elements 13 are housed. The scraper elements 13 are supported by axially staggered parallel pairs of pins 14 in corresponding radial guide holes formed in the paddle blades 3. They are subjected to an radially outward elastic force by springs which are not illustrated in detail. The free ends of the supporting pins 14 terminate in housing slots 15 provided in the blades 3 for the application of locking elements to prevent extraction. According to a further characteristic, the arms 2, 2' are fixed by welding to a cylindrical hub 101, 104, which has a central hole which may be sealed with a plug 17, for example and in particular one made of plastic material. In the case of the drive shaft section 1, the cylindrical hub 101 is fixed at the end of this section or is made in one piece with it. Among the advantages of the invention, it will be evident that by using a reduced number of standard elements like the hubs 4, the radial arms 2 and the paddle blades 3, it is possible to assemble a great variety of agitators, differing by diameter, or by axial length, or by both said said parameters, or even by the number of paddle blades which may be assembled on the agitator.

Claims: Agitator for ice-cream making machines of the type comprising a plurality of radial paddle blades (3) which are connected by their opposite ends at equal angular intervals to the free ends of radial arms (2, 2') secured to a rotary drive shaft section (1) and to a connecting hub (4) coaxial with the said drive shaft section (1), in which the said paddle blades (3) are made of plastics material and in which the radial extension of the paddle blades (3) is considerably larger than, and more than twice as great as, the radial extension of the said supporting arms (2, 2'), and from half to two thirds of the total radial extension of the agitator is constituted by the radial extension of the paddle blades (3). Agitator according to Claim 1 or 2, characterized by the fact that the paddle blades (3) are formed from plates with a helical development disposed substantially radially with respect to the axis of rotation. Agitator according to one or more of the preceding claims, characterized by the fact that the paddle blades (3) are fixable in a removable way to the radial arms (2,2') of the shaft section (1) and of the connecting hub (4). Agitator according to one or more of the preceding claims, characterized by the fact that the paddle blades (3) are secured to the arms (2,2') by means of radial bolts (5) which are completely enclosed within the thickness of the plates forming the blades (3) and which are screwed into threaded radial holes (8) formed in the arms (2,2'). Agitator according to claim 5, characterized by the fact that the heads of the bolts (5) are accessible from the the radially outer side of the paddle blades (3) through radial cavities (6) which may be sealed with plugs (7). Agitator according to claim 6, characterized by the fact that the plugs (7) are made of plastics material and may be inserted by forcing into the cavities (6) Agitator according to one or more of the preceding claims, characterized by the fact that each paddle blade (3) carries one or more scraper elements (13) which are supported in such a way as to be urged under elastic pressure radially towards the exterior. Agitator according to one or more of the preceding claims, characterized by the fact that the paddle blades (3) and the corresponding arms (2,2') are provided with complementary centering means (9,10,11). Agitator according to claim 9, in which the said centering means comprises each a pair of coinciding radial holes (9,10) housing a centering pin (11).

Inventors: COCCHI GINO, COCCHI, GINO
Applicants: CARPIGIANI GROUP ALI SPA, ALI S.P.A. - CARPIGIANI GROUP
Application year: 1993
Main classification: A23G9
IPC codes: A23G9