GB2563039A

GB2563039A - Bean Grinder Lid

Info

Publication number: GB2563039A
Application number: GB1708633.1A
Authority: GB
Inventors: John Nicholson Martin
Original assignee: NICHOLSON DESIGN CONSULTANTS Ltd
Current assignee: NICHOLSON DESIGN CONSULTANTS Ltd
Priority date: 2017-05-31
Filing date: 2017-05-31
Publication date: 2018-12-05
Also published as: EA201992429A1; GB201708633D0

Abstract

A bean grinder 1 comprises a reservoir 47, defined by a reservoir body, in communication with a set of grinding burrs, wherein at least one of the grinding burrs is driven by an electric motor 23. The grinder further comprises a cover 98 hingedly coupled to the reservoir body such that in a closed configuration the reservoir is covered by the cover and access to the reservoir is prevented, and in an open configuration access to the reservoir is permitted. The electric motor has an immobilising switch 97 having an operating position which permits the operation of the motor, and an immobilised position in which operation of the motor is prevented. The cover includes a switch engagement element 103 that positions the immobilising switch in the operating position when the cover is in its closed configuration. The switch may be biased to its immobilised position and may interrupt power to the motor in the immobilised position. The switch engagement element may comprise a rod which is received in apertures of the immobilising switch.

Description

BEAN GRINDER (LID)

The present invention relates to a bean grinder, particularly though not exclusively a coffee bean grinder.

In a coffee grinder, it is desirable to;

• Prevent, for safety reasons, user access to the grinding burrs of a bean grinder while the grinding burrs are in driven rotation.

• Allow, for ease of refilling, adjustment and cleaning, user access to the grinding burrs, bean funnel and adjustment collar of a bean grinder, while the grinding burrs are not in driven rotation.

• Prevent beans or fragments of beans from being ejected from the bean grinder during the grinding operation.

• Allow user visibility of both the beans waiting to be ground and the beans in the process of being ground.

The object of the present invention is to provide an improved bean grinder.

According to the invention I provide a bean grinder (1) comprising a driven burr (3) and a complimentary fixed burr (4) and funnel (47) mounted above the burrs for introducing a flow of beans (47) to the burrs. The funnel comprises an orifice (104), a tapered aperture (60) for delivering the beans, a threaded collar (48) for adjusting the axial separation of the burrs. Pivotally mounted by a hinge (102) positioned to one side of the funnel a lid (98) covering the entrance orifice (104) to the funnel. Advantageously the lid is provide with a magnetic latch (99) to ensure the lid is securely closed during operation and a lid projection (103) that acts on a plunger (101) which in turn activates a microswitch (97) to supply power to the drive motor (23). Thus the driven burr is only powered when the lid is in the closed and orifice covered position. The lid is pivotable to an open position where it freely rests. When the lid is in the open position free and easy access is possible to the funnel and burrs for cleaning and refilling and no power can be supplied to the driven burr because the plunger is not engaged by the lid projection. The interlock is made and rotational energy is supplied to the driven burr only when the lid is in the closed position i.e.

fully covering the funnel entrance orifice and the burrs.

Advantageously the interlock can use any combination of electronic, mechanical, magnetic or optical features to sense when the lid is closed and rotational power should be supplied to the driven burr.

Preferably the lid is made from clear polymeric material with good engineering properties such as polycarbonate, so as to both allow clear visibility of the funnel, its contents and the burrs and prevent access to the rotationally driven burrs during grinding i.e. access to the burrs is prevented when the lid is closed by completely covering the grind funnel orifice and access is allowed when the lid is open position.

To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which:

Figure lisa perspective view of a bean grinder;

Figure 2 is a side section view of the bean grinder of figure 1 taken along A-A Figure 3 is an enlarged side section detail view of the bean grinder of figure 1;

Figure 4 is a rear section view of the bean grinder of figure 1 taken along A-A;

Figure 5 is a perspective exploded view of the bean grinder;

Figure 6 is a horizontal section view of the bean grinder of figure 1;

Figure 7 is a perspective partial section view of the bean grinder of figure 1; Figure 8 is a detailed view of the base of the bean grinder of figure 1.

Referring to the drawings, a bean grinder 1 with a body 2 has an inner grinding burr 3 and a complementary outer grinding burr 4. The burrs are commercially available from Italmill Grinding Technology S.r.l for instance. The inner burr is carried on a shaft 5 journaled in a bearing 6 locating the axis A of rotation of the inner burr. The outer burr is transversely located in a recess 7 in a support 8. The bearing is carried concentrically with the recess, whereby the inner burr on the shaft and the outer burr in the recess are held at least substantially concentric.

To assure concentricity of the bearing 6 with the recess 7, it is carried in a bearing support plate 9, which is a clearance fit in the recess, thus transversely located in it. The outer race 10 of the bearing is a push fit in a seat 11 in the underside of the plate and captivated between the seat and a bottom 12 of the recess.

Screws 14 pulling the plate against the recess bottom 12 pass through this and engage in an intermediate member 15, itself held fast via screws 16 with a lower body portion 17 of the grinder. An upper body portion 18 has the outer burr support 8 formed in it, whereby the two sets of screws attach the body portions together. To ensure their local concentricity the intermediate member has a flanged rim 19 engaging in both these portions.

A drive mechanism 21 is provided for inner burr 3 and the shaft 5 which is the output shaft of a two stage epicyclic gearbox 22 driven by a motor 23 below it. These components are well known and will not be described in detail. The motor has a housing 24 having two lugs 25 extending down from it. Via elastomeric bushes 26, they engage in sockets 27 arranged in a lower end 28 of the lower body portion 17. The lugs react the torque generated between the burrs during grinding. The thrust generated in grinding is reacted as described below.

A grounds expulsion member 31 is provided between the inner burr 3 and the bearing support plate 9. It has three swept back radial fingers 32, which move grounds out radially. The fingers radiate from a hub 33, which although recessed to accommodate a boss 34 of the bearing support plate 9, in which the bearing 6 is accommodated, has a central sleeve 35 extending along the shaft 5, to abut the inner race 36 of the bearing. Grinding thrust downwards on the inner burr is reacted via the sleeve 35 and inner race 36 to the outer race 10 and the recess bottom 12. When a screw 37 holding the inner burr to the shaft is tightened, its compression of the sleeve 35 is reacted via the inner race to a circlip 38 mounted on the shaft 5 beneath the inner race 36.

Whilst the outer burr 4 is adjustable in its approach to the inner burr 3, as described below, the outer burr must not rotate. To ensure this, it has an upper attachment 41 fixed to it by screws 42 extending up through it. The attachment has a pair of tabs 43 extending radially which are received in slots 44 cut in the side of the support 8. The slots have blind bores 45, accommodating springs 46. The tabs and slots co-operate to hold the outer burr against rotating and the tabs and springs urge it upwards, i.e. urge the outer burr upwards away from the inner burr.

A grind adjustment funnel ring 47 acts down on the upper attachment 41 of the outer burr 4. It has a threaded collar 48 received in a threaded bore 49 of the upper body portion 18 above an outwards of the outer burr support 8. Screwing the funnel ring in urges the outer burr down and unscrewing allows it to rise. The funnel ring carries a setting ring 51. The two rings have co-operating lips 52,53, which hold the setting ring on the funnel ring. Inside, the setting ring has a series of indents 54. The funnel ring has a bore 55 at the level of these indents in which is accommodated a spring 56 and a detent ball 57. The arrangement allows the setting ring to be adjusted on the funnel ring and hold its adjustment. On a radial face at the top of the upper body portion, indicia 58 are moulded. In use, the funnel is wound in to bottom the outer burr, the setting ring is zeroed by aligning a mark 59 on the outside of setting ring with the zero of the indicia. The funnel ring is then backed off by the number of indicia corresponding to the required grinding separation of the burrs. The threading of the collar 48 and the bore 49 is fine, whereby friction in between the funnel ring and the upper bore portion holds the funnel ring in its adjusted position. This in turn allows the funnel ring to resist upwards thrust on the outer burr generated in bean grinding.

The funnel ring 47 has a tapered aperture 60 for funnelling beans 61 to the burrs.

The grounds from the burrs drops into the path of the swept back radial fingers 32 of the grounds expulsion member 31. They pass the grounds to a pair of vertically arranged openings 62 in the wall 63 of the burr support recess 7, at the lowest point of the bearing support plate 9. This slopes at a normal angle of 15° to horizontal, the axis A of rotation of the inner burr 3 and the drive mechanism 21 being at this angle to the vertical.

A spout 64 is provided for receiving the grounds. It has an inclination of 10° to the vertical in the opposite direction to that of the axis A. It provides a grounds path P from the grinder. It will be noted that the axis A and the path P form an invert V. The point of the V substantially at the burrs, although the true intersection of the axis A and the centre line of the spout is slightly above the burrs. Whist the spout is slightly more upright than the axis A, the bisector of the V is effectively vertical.

The spout 64 is generally circular in cross-section. At its upper end 65, it is shaped to abut the outer contour 66 of the recess 7, with a top pin 67 engaging in a recess 68 formed in the outer contour. A lug 69 engages the underside of the recess bottom 12 at a cut-out 70 in the intermediate member 15. A screw 71 bearing on the bearing support plate 9 passes through the bottom 12 and engages in the lug to positively locate the spout. It also passes through an aperture 72 in the lower body 17.

The lower body 17 has a base 81 fitted beneath it and projecting forwards to extend beneath the spout. The base 8land the body 2 are in invert 7 configuration.

The base 81 has a two part stand 82 for a grounds collection cup 83. With the cup on the stand, beneath the bottom 84 of the spout, the invert V configuration of the axis A and the grounds path P, taking account of the tall/thin configuration of the drive mechanism 21 and the lower body 17 closely following the drive mechanism below the spout aperture 72, the arrangement allows the cup to collect the grounds 85.

In development of the bean grinder, which will normally be used for grinding coffee, whilst little grounds remained neither in the burrs nor at the bottom of the burr support recess, there was a tendency for grounds to hang up in the spout especially during certain weather conditions. This appears to be an electrostatic effect, due to the manner in which the grounds collect on the spout, particularly at the bottom 84 and spout aperture 72.

Surprisingly it was found that by making the stand 82 of wood, and indeed by providing wooden feet 86, the electrostatic grounds hang up disappeared.

Consistently I have ground say lOgm of beans and collected lOgm of grounds (the exact weights depending on the weight of an integer number of coffee beans). This effect was achieved with a steel grounds cup, a plastics material spout and a metallic body.

The two part stand comprises a cover 87 over most of the hollow base 81, and 5 held in place by a screw 88 having a head 89 left proud, and a circular saucer 90 with a blind central bore formed in its base for location on the screw head 89.

The rear of the hollow base has inside a cable control moulding 91 with an aperture 92 opening outwards for a power cable 93 and a clamp 94 for the cable as it passes up into the lower body portion. The arrangement allows the cable to be inserted into the base for storage and withdrawn for use.

The cable extends in the lower body to a printed circuit board 95 accommodated alongside the gearbox 22. It has a switch 96 for initiating supply of power to the motor. The printed circuit board has an interlock micro-switch 97. The upper body has a lid 98 pivotally mounted at the rear by a hinge 102 for closing over the funnel ring 47. The lid carries a magnet 99 and the upper body a steel insert 100. These hold the lid closed over the funnel for use of the grinder. In this fully closed position, a lid projection 103 feature on the lid 98 depresses a plunger 101 and the micro-switch makes contact to allow the grinder to operate when the switch 96 is activated. When the lid 98 is opened and before a point when access can be gained to the tapered aperture 60, the lid projection feature 103 disengages from the plunger 101 and the micro-switch breaks contact to prevent the grinder to operate when the switch 96 is activated.

The materials of the components of the bean grinder can be chosen as at will.

I envisage that the body portions, the base, the grounds expulsion member and the bean funnel will be of light alloy. The spout, the setting ring, the intermediate member and the bearing support plate will be of polymeric material. The lid will be of transparent polymeric material to allow visibility of the tapered aperture, setting ring and grinding burrs. The wooden parts will of course be of wood.

The invention is not intended to be restricted to the details of the above described embodiment. For instance, the setting indicia could be provided on the setting ring with the zeroing mark being provided on the upper body portion or the burrs could be flat burrs rather than conical burrs or the motive power source could be human hand.

Claims

CLAIMS:

1. A coffee bean grinder comprising a reservoir in communication with a set of grinding burrs, wherein the grinding burrs are driven to rotate by an electric motor; the reservoir is defined by a reservoir body; the grinder further includes a cover

5 hingedly coupled to the reservoir body and having a closed configuration in which the reservoir is covered by the cover and access to the reservoir is prevented, and an open configuration in which access to the reservoir is permitted; the electric motor includes an immobilising switch having an operating position which permits the operation of the motor, and an immobilised position in which operation of the motor is prevented;

10 the cover includes a switch engagement element; and wherein the switch engagement element positions the immobilising switch in the operating position when the cover is in its closed configuration.

2. A coffee bean grinder according to Claim 1, wherein the immobilising switch is biased to its immobilised position.

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3. A coffee bean grinder according to Claim 1 or Claim 2, wherein the immobilising switch interrupts power to the electric motor when in its immobilised position.

4. A coffee bean grinder according to any of Claims 1 to 3, wherein the switch engagement element comprises a projecting rod and the immobilising switch defines an apertures which is sized and configured to receive therein the projecting rod.

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5. A coffee bean grinder according to any of Claims 1 to 4, wherein the reservoir includes an opening and the cover covers the entirety of the reservoir opening when in its closed configuration.

6. A coffee bean grinder according to any of Claims 1 to 5, wherein the cover is transparent.

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7. A coffee bean grinder according to any of Claims 1 to 6, wherein the cover and/or the reservoir body includes a latch configured to releasably retain the cover in its closed configuration.

8. A coffee bean grinder according to any of Claims 1 to 7, wherein the grinding burrs are variable to vary the output of ground coffee beans; the grinder includes a

30 manual controller which controls the grinding burrs; and the cover further covers the manual controller when in its closed configuration.

Intellectual

Property

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