COFFEE-GRINDER

Abstract: Coffee-grinder of the type with grinding group having coaxial toothed wheels (12) with a rotating toothed part with respect to a fixed toothed crown (123) with internal charging of the grains and peripheral discharge of the fine ground coffee (116), characterised in that: said fixed toothed crown (123) is substantially spiral-like flat with decreasing pitch towards the periphery and fixed on an overhanging fixed supporting means (112-1231) said rotating toothed part is made up of two parts: a substantially flat counter-crown (122) toothed like the fixed one, spiral-like with decreasing pitch towards the periphery (122') for grinding the beans into an always finer size (123'-122') and a pinion (121) having a star-like pyramidal shape (121') with a fin-like shaped toothing which extends with grooves becoming always less deep towards the periphery of the lower base (121') which substantially develops for the whole height of said fixed crown (123) and counter-crown (122).

Description: 1 DESCRIPTION COFFEE-GRINDER Technical Field The present invention has for object a coffee-grinder especially to grind coffee into grains ready for use in coffee machines. Background Art In prior art, coffee-grinders to be generally used associated to a proportioning device, on the side of the espresso coffee machine, to deliver the ground coffee to said coffee machine, are known. These coffee-grinders are generally made up of two generally conical and/or more or less flat annularly shaped toothed wheels, one of which turns while the other remains fixed, forcing the coffee grains to be crushed and then to be finely pulverized before flowing into the proportioning device. The prior art drawbacks substantially are that the grinding is rough or in any event not regular enough. Purpose of the present invention Purpose of the present invention is that of avoiding the aforementioned drawbacks and substantially improving the grinding operations. Essence of the invention The problem is solved as claimed by means of a coffee-grinder of the type with grinding group having coaxial toothed wheels with a rotating toothed part, with respect to a fixed toothed crown, operating by internal charging of the grains and peripherally externally discharging the finely ground coffee, characterised in that: - said fixed toothed crown is substantially spiral-like flat with decreasing pitch towards the periphery and fixed on an overhanging fixed supporting means ; - said rotating toothed part is made up of two parts: - a substantially flat counter-crown similarly toothed to the fixed one, spiral-like with decreasing pitch towards the periphery to grind the beans progressively finer; - on the inside of said fixed crown and said counter-crown, a pinion having a star-like pyramidal shape with a fin-shaped toothing which extends with grooves becoming always less deep towards the lower base periphery, which substantially develops for the entire height of said fixed crown and counter-crown, and whose toothing is aimed, with the upper wide pitch, at crushing the grains against the upper teeth of said fixed crown, to then convey them towards the annular mouth having a substantially horizontal "V" shaped section, for the subsequent grinding between said fixed crown and rotating counter-crown together with said pi nion . Advantages of the new solution In this way, one has the advantage of obtaining a perfect grinding with the highest yield, quality and regularity of the ground product. Description of at least one form of embodiment of the invention These and other advantages will appear from the following embodiments with the aid of the enclosed drawings, whose details are not to be considered limitative but only supplied as examples. Figure 1 is a sectional view of the coffee-machine mounted on a coffee proportioning device together forming a grinder-proportioning device. Fig. 2 is an enlarged view of the coffee-grinder grinding group. Fig. 3 is an even larger view of the grinding group. Fig. 4 is a partial sectional top view of the grinding group. As claimed, the innovation concerns a coffee-grinder of the type with grinding group having coaxial toothed wheels (12) with a rotating toothed part with respect to a fixed toothed crown (123) with internal charging of the beans and peripheral discharge of the fine ground coffee (1 16), characterised in that: - said fixed toothed crown ( 123) is substantially spiral-like flat with decreasing pitch towards the periphery and fixed on an overhanging fixed supporting means ( 1 12-1231 ); - said rotating toothed part is made up of two parts: - a substantially flat counter-crown (122) toothed like the fixed one, spiral-like with decreasing pitch towards the periphery ( 122') to grind the beans into an always and progressively finer size (123' - 122'); - inside of said fixed crown and said counter-crown, a pinion (121) having a star-like pyramidal shape (121 ') with a fin-like shaped toothing which extends with grooves becoming always less deep towards the periphery of the lower base (121 "), which substantially develops for the whole height of said fixed crown (123) and counter-crown (122), and whose toothing is aimed, with the upper wide pitch (121 ') at crushing the beans against the upper teeth of said fixed crown (123'), to then convey them towards the annular mouth having a substantially horizontal "V" shaped section, for the subsequent grinding between said fixed crown (123) and rotating counter-crown (122) together with said pinion (121). More in detail, according to the figures: 1 indicates the coffee-grinder and 2 indicates the proportioning device which receives the ground coffee from the periphery (1 16) of the grinding group ( 12) of the coffee-grinder. The coffee-grinder has a hopper for the coffee (1 10) which determines a mouth of the coffee in grains which must be ground (1 1). The hopper (1 10) rests on a support (1 1 1 ) which in turn rests on a counter-support ( 1 12) which supports a conveyance funnel (1 14) to the grinding group ( 12). The whole is contained in a cylinder-like support (113) with side opening ( 1 16) for the pouring of the powdered ground coffee into the proportioning device (2). The cylinder-like support (1 13), is embedded in the containing carter which makes up the coffee-grinder cover (1 15 ). The cylinder-like support ( 1 13) is fixed to a vertical electric motor structure ( 13) supported by underlying uprights ( 15), able to be disassembled. The rotor (135) of the electric motor (13) completed by the stator (134), has a fan (14) on the lower side, and on the upper side extends with a motor axis (131 ), which by means of a key (133) locks said star-like toothed pinion (121 ) of the grinding group (12). The motor axis (131 ), also keys with said key (133) a supporting rotating washer ( 132), with labyrinth seal ( 1321 ), which supports by screw locking (1220) said counter-crown (122). From Figure 4 it may be noticed that: - said pinion has an eight-point star-like toothing. The toothing of the crowns is substantially realised with a 6° pitch.

Claims: Claims 1. Coffee-grinder of the type with grinding group having coaxial toothed wheels (12) with a rotating toothed part with respect to a fixed toothed crown ( 123), operating by internal charging of the grains and peripherally externally discharging the fine ground coffee ( 1 16), characterised in that: - said fixed toothed crown ( 123) is substantially spiral-like flat with decreasing pitch towards the periphery and fixed on an overhanging fixed supporting means ( 1 12- 1231 ); - said rotating toothed part is made up of two parts: - a substantially flat counter-crown (122) toothed like the fixed one, spiral-like with decreasing pitch towards the periphery ( 122') for grinding the grains into an always finer size (123' - 122'); - on the inside of said fixed crown and said counter-crown, a pinion (121) having a star-like pyramidal shape ( 121 ') with a fin-like shaped toothing which extends with grooves becoming always less deep towards the periphery of the lower base (121 ") which substantially develops for the whole height of said fixed crown (123) and counter-crown (122), and whose toothing is aimed, with the upper wide pitch (121 ') at crushing the grains against the upper teeth of said fixed crown (123'), to then convey them towards the annular mouth having a substantially horizontal "V" shaped section, for the subsequent grinding between said fixed crown (123) and said rotating counter-crown ( 122) together with said pinion ( 121 ). 2. Coffee-grinder according to claim 1., characterised in that its has a hopper for the coffee (1 10) which determines a mouth of the coffee in grains which must be ground (1 1 ), the hopper (1 10) resting on a support (1 1 1 ) which in turn rests on a counter-support (1 12) which supports a conveying funnel ( 1 14) to the grinding group ( 12). 3. Coffee-grinder according to the previous claims, characterised in that it comprises a cylinder-like support (1 13) which includes said grinding group (12), which is embedded in the containing carter (1 15) which makes up the coffee-grinder cover ( 1 ), such cylinder-like support ( 1 13) being fixed to a vertical electric motor structure ( 1 3) supported by underlying uprights ( 1 5), able to be disassembled, and in which the rotor (135) of said electric motor (13) completed by the stator (134), has a fan (14) on the lower side and on the upper side extends with a motor axis (131), which by means of a key (133) locks said star-like toothed pinion (121 ) of the grinding group 12 and a supporting rotating washer (132), which supports by screw locking (1220) said counter-crown (122). 4. Coffee-grinder according to the previous claims, characterised in that said pinion ( 121 ) has an eight-point star-like toothing (121 '). 5. Coffee-grinder according to the previous claims, characterised in that the crowns toothing is substantially realised with a 6° pitch. 6. Grinder-proportioning device involving a coffee-grinder according to any of the previous claims.

Applicants: SAN MARCO SPA, LA SAN MARCO S.P.A.
Application year: 1999
Main classification: A47J42
IPC codes: A47J42