Abstract:
A cordless electric condiment grinder includes a hollow housing elongated to extend between a base for supporting the grinder uprightly and an opposing top, the top of the housing having a bulbous form to define a condiment reservoir. A rotary grinding mechanism is disposed in a lateral opening in the top of the housing and a tilt switch controls operation of the grinding mechanism, allowing freshly ground condiment to be dispensed automatically upon rotating the grinder through an acute angle and thus is particularly suited for use by people with limited dexterity.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to grinders for condiments such as pepper or salt, and particularly to grinders driven by electric motors 
       BACKGROUND OF THE INVENTION 
       [0002]    Hand-held cordless electric grinders provide a convenient and fast method for dispensing freshly ground pepper, salt, or other condiments. A conventional grinder of this type has an elongate housing which defines a grip by which the grinder is held and which has first and second longitudinally opposing ends. A battery compartment at the first end of the housing provides power to an electric motor connected via a speed reduction geartrain to a drive shaft. The drive shaft extends through a condiment reservoir to a grinding mechanism at the second end of the housing. In an upright design the second end may be supported on a table, or a like horizontal surface, when not in use. However, a drawback of this is that, following use, the impact caused by placing the grinder upon a table tends to dislodge condiment particles from or through the grinding mechanism which drop from the grinder and, for instance, may soil a table cloth. 
         [0003]    An inverted design is therefore preferable, in which the first end is adapted to be supported upon the table so that the second end is uppermost and a recess is provided in the housing to catch any particles dislodged following use. However, an inverted grinder of this type has ergonomic drawbacks as it is necessary to rotate the grinder approximately 180° to dispense the ground condiment and this can be troublesome for people having reduced mobility of the forearm and wrist. Moreover, operating a switch to initiate grinding at the same time as rotating the grinder in this manner can pose further difficulties to disabled people. One object of the invention is to provide a condiment grinder which addresses these drawbacks. 
         [0004]    There is a continuing need for improvements to electric condiment grinders of this type. In particular there is a need for designs that are able to be manufactured more cost-effectively. The grinder should have an efficient geartrain with a low weight and inertia and which can be readily installed. It should also be compact with coaxial drive and driven shafts, quiet in operation, while being able to operate at high motor speeds. It is a further object of the present invention to address the above needs or more generally to provide an improved condiment grinder. 
       DISCLOSURE OF THE INVENTION 
       [0005]    According to one aspect of the present invention there is provided a condiment grinder comprising: 
         [0006]    a hollow housing elongated to extend between a base for supporting the grinder uprightly and an opposing top, the top of the housing defining a condiment reservoir; 
         [0007]    a filling opening in the reservoir for loading condiment; 
         [0008]    a lateral opening in the housing, the lateral opening in communication with the reservoir; 
         [0009]    an electric motor within the housing; 
         [0010]    a battery holder within the housing, the battery holder having contacts for engaging the terminals of batteries received therein; 
         [0011]    a switch electrically connected to the contacts for selectively supplying power to the motor; 
         [0012]    a rotary grinding mechanism for grinding the condiment, the grinding mechanism being disposed in the lateral opening to dispense ground condiment therethrough, and 
         [0013]    transmission means for transmitting torque from the motor to the grinding mechanism. 
         [0014]    Preferably the top and the base of the housing are relatively broad and are separated by a waist portion adapted to provide a grip for holding the grinder, the base has a planar surface for supporting the grinder upright and the top has a convex surface. 
         [0015]    Preferably a recess in the housing extends about the lateral opening, the recess having peripheral walls, the grinding mechanism being completely recessed within the housing and a lower section of the peripheral walls being upwardly concave to catch any condiment particles dislodged from or through the grinding mechanism when the grinder is generally upright. 
         [0016]    Preferably the switch is a tilt switch for automatically actuating the motor when the grinder is tilted from an upright position to direct the lateral opening downwardly. 
         [0017]    Preferably the grinding mechanism includes a rotor and stator cooperating for grinding the condiment therebetween, the stator being fixed in the lateral opening, the rotor being mounted to a drive shaft extending through the reservoir, the transmission means includes an epicyclic geartrain driven by the motor and a bevel gear pair connected between the epicyclic geartrain and the drive shaft. Preferably the motor and epicyclic geartrain are generally disposed within the waist portion. 
         [0018]    Preferably one bevel gear of the bevel gear pair, the epicyclic geartrain and an output shaft of the motor are coaxial with a first axis, the first axis being inclined acutely to a longitudinal axis of the waist portion and the other bevel gear of the bevel gear pair is coaxial with the drive shaft to rotate about a second axis orthogonal to the first axis. 
         [0019]    Preferably the epicyclic geartrain includes a plurality of spur gear epicyclic gearsets, each gearset comprising planet gears meshed with a sun gear, the planet gears of each gearset supported upon a planet carrier, the gearsets stacked within a common ring gear with the sun gears coaxial, adjacent sun gears and planet carriers of adjacent gearsets being rotationally fast for transmitting torque between the adjacent gearsets. 
         [0020]    This invention provides a grinder which is ergonomically efficient in operational use. It is particularly well-suited to use by people having reduced mobility of the forearm and wrist, who are able to operate the grinder simply by grasping and rotating it through a small angle, preferably of 40° to 50°. Moreover this is achieved with a design able to catch any condiment particles dislodged from or through the grinding mechanism when the grinder is generally upright. It has a simple construction employing a number of common parts for reduced manufacturing costs. It includes modular components with a low weight and inertia, it is compact, relatively efficient and quiet in operation, and is able to operate at high motor speeds. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: 
           [0022]      FIG. 1  is a side elevation of an exemplary embodiment of the grinder of the invention; 
           [0023]      FIG. 2  is a schematic central longitudinal cross section along line AA of  FIG. 1 ; 
           [0024]      FIG. 3  is a schematic fragmentary longitudinal cross section of the housing of the grinder of  FIG. 1 ; 
           [0025]      FIG. 4  is a transverse cross section along line BB of  FIG. 2 , and 
           [0026]      FIG. 5  is a schematic of the gear train of the grinder of  FIG. 1 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Referring to  FIGS. 1-5  of the drawings, a hand-held cordless electric grinder according to an exemplary embodiment of the invention includes a hollow housing  10  having an asymmetrical waisted form, with an elongate waist portion  11  which provides a grip for holding the grinder. The waist portion  11  separates the base  12  from the bulbous top  13  which both have relatively broader dimensions. The base  12  has a planar face  14  for supporting the grinder upright on a horizontal surface, the face  14  extending orthogonally to a longitudinal upright axis  15  of the waist portion  11 . 
         [0028]    A battery holder  16  is provided in the housing  10  below an electric motor  17  having a shaft  46  rotating about the drive axis  18  which is inclined acutely to the axis  15 . The battery holder  16  has contacts  40  for abutting the battery terminals (not shown). The battery holder  16  and motor  17  are fixed inside a tubular mounting assembly  19 , to one axial end of which the battery holder  16  is fixed. The battery holder  16  is located near the base  12 , such that with batteries in place the centre of gravity is lowered for stability. 
         [0029]    Mounted to the battery holder  16  is a tilt switch  20  which is electrically connected in a circuit (not shown) between the contacts  40  and the motor  17  to control operation of the motor depending upon the inclination of the grinder. The tilt switch preferably has a differential angle of 40°-50° and in the preferred embodiment shown is a roller ball type. 
         [0030]    An epicyclic geartrain  21  driven by the motor  17  supplies torque through a shaft  22  to a bevel gear pair  23 ,  24 . The shaft  22 , bevel gear  23  and geartrain  21  are coaxial with the motor axis  18 . The bevel gear  23  is meshed with bevel gear  24  to transmit the torque through 90° to a drive shaft  25  extending through a condiment-receiving reservoir  27  bounded by the external walls in the bulbous top  13  and an internal wall  29 . 
         [0031]    The motor  17 , battery holder  16  and epicyclic geartrain  21  are received in a recess  28  in the housing  10  separated from the condiment reservoir  27  by the internal wall  29 . 
         [0032]    The outer end of the shaft  25  drives a grinding mechanism  56 . The shaft  25  is rotationally fast with the grinding rotor  26  which cooperates with, and is generally received within, a grinding stator  30  for grinding the condiment therebetween. The grinding mechanism  56  is of a unidirectional type, which has helical teeth (not shown) and thus operates best in one direction. An adjuster nut  31  received on a threaded tip  32  of the shaft  25  engages and moves the rotor  26  axially for adjusting the size of the annular discharge opening  33  between the rotor  26  and stator  30 , and hence the fineness of the ground condiment. The stator  30  is fixed in a lateral opening  41  in bulbous top  13  in which the reservoir  27  is formed. An upper opening  44  in the reservoir  27  is provided for loading condiment and is closed by a closure  45 . 
         [0033]    The lateral opening  41  in the housing  10  is provided in the top  13 . The components of the grinding mechanism, including the rotor  26 , stator  30  and adjuster nut  31  are completely recessed within the housing  10 . Ground condiment from the discharge opening  33  passes out through the recess  34  in use. The recess  34  extends about the lateral opening  41  and has annular peripheral walls  37  and a rim  35  lying in a plane  36  inclined acutely to the upright axis  15  and the lateral opening  41  extends centrally through the recess  34 . The lower section of the walls  59  is upwardly concave to catch any condiment particles dislodged from or through the grinding mechanism  56  when the grinder is generally upright. 
         [0034]    The epicyclic geartrain  21  includes four spur gear epicyclic gearsets  111 - 114  mounted coaxially. Each of the gearsets  111 - 114  comprises planet gears P 1 , P 2 , P 3 , P 4  meshed with a respective sun gear S 1 , S 2 , S 3 , S 4  and supported upon a planet carrier C 1 , C 2 , C 3 , C 4 . The planet carriers C 2 , C 3 , C 4  are of common construction, each integrally formed and rotationally fast with a respective one of the sun gears S 1 , S 2 , S 3 . The planet carriers C 1 , C 2 , C 3 , C 4  include three integral parallel, equally angularly spaced shaft portions for supporting the three planet gears P 1 , P 2 , P 3 , P 4 . The gearsets  111 - 114  are stacked within a non-rotating ring gear R, with which all the planet gears P 1 , P 2 , P 3 , P 4  mesh. At the output of the geartrain  21  a coupler  50  transmits torque from the carrier C 1  to the shaft  22 , while at the input to the geartrain the motor shaft  46  is rotationally fast with the sun gear S 4 . 
         [0035]    In use, pepper may be placed in reservoir  27 . Grasping the waist portion  11  and tilting the grinder about 40°-50° from the horizontal to incline the recess  34  downwardly is sufficient to cause the motor  17  to be actuated by operation of the tilt switch  20 . Torque is thus transmitted through the epicyclic geartrain  21 , shaft  22 , bevel gear pair  23 ,  24 , and shaft  25  to the grinding mechanism  56 . Condiment drops from the reservoir  27  into the grinding mechanism  56  and thus passes in ground form through the lateral opening from which it is dispensed. The tilt switch  20  opens when the grinder is supported upright when not in use, to stop the motor. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.