FLOUR STOCK
Background of the Invention Sieveings for flour and similar powdery foodstuffs, particularly sieves of the type that are attempted to be held and handled by one hand, commonly include a container body with a sieve screen bottom, a stirring element above the screen, and a handle assembly, to retain the sieve and manipulate the agitator. Sieve of this type, to be practical, must allow the uninterrupted movement of the agitator mechanism in a smooth, comfortable manner and requires minimal effort on the part of the user. This can be difficult to achieve, particularly in the form of a sieve in which the reciprocal movement of the hand will move in an oscillating rotary motion of the agitator. Consideration should also be given to the durability of the sieve and the ability to operate its components freely while holding onto the flour debris, as an inherent byproduct of the sieve operation. Another potential difficulty with respect to known sieves arises due to the open nature of the bottom of the sieve. In other words, there will be a natural tendency for the flour to fall loosely through the bottom of the sieve, even when unloading is not desired, such as when the sieve is moved from one point of use to another or when the sieve is temporarily stored. sieve with at least a portion of its contents held there. SUMMARY OF THE INVENTION It is intended that the sieve of the present invention incorporates, in a commercially feasible and practical construction, advantages which improve only this sieve, avoiding the drawbacks of the known sieves, by the provision of a greater ease of operation and for the protection of the product, both during use and during periods when it is not used. The relationship between the components of a sieve, for its operating components and for its fixed components, must provide an operation that is both efficient and free of problems. Basically, the inventive sieve includes a vertically elongated cylindrical container, with a flared upper end portion, terminating in an upwardly directed mouth, adapted to receive a seal or seal that snaps there under pressure. The container includes an integral bottom wall in the nature of a screen sieve slightly displaced upwardly from the lower edge of the peripheral wall of the container, thereby defining an underlying chamber with a peripheral wall around it. The seal includes a central closed dome portion, displaced upward, which can be frictionally engaged, removably, within the bottom chamber for the selected closure of the bottom of the screen to prevent unwanted discharge when one wishes to retain temporarily flour inside the sieve. Two of these seals can be supplied when it is convenient to close both the upper and the bottom part of the container body. The operation components of the sieve include a stirrer or rotor, with a series of blades projecting radially, parallel to and closely superimposed on the inner face of the sieve for agitation and forced movement of the flour. The rotor includes a dependent central bifurcated tongue, which snaps into an opening in the hub, projecting upwards, of a crank wheel underlying the screen and coaxial with it. The crank wheel, in turn, includes a crank arm, which projects radially, with an elongated radial slot. The movement of the rotor is controlled by a trigger, manually gripped, pivotally mounted to a handle extending outward from one side of the container. The trigger mounts an elongated trigger bar, which extends therefrom and terminates in an elongated pulse arm, immediately underlying the bottom of the screen and supported, in a sliding manner, between the screen and the underlying wheel. The impulse arm includes a cam edge which, due to the flexible resilience inherent of the impulse arm, it is retained against the wheel hub as the impulse arm, through the action of the trigger, which moves there reciprocally. The pulse arm includes a dependent pin, which is received rotatably within the elongated slot of the crank arm of the wheel, whereby the reciprocal movement of the pulse arm effects a corresponding rotation of the wheel, which, at its Once, it is transferred in the reciprocal rotary movement of the rotor and the blades. The cam edge of the pulse arm includes a central lobe, positioned to selectively radially outwardly move the pulse arm and pin relative to and within the elongated slot of the crank arm, as the pulse arm moves to through its travel section, where there will normally be a slight resistance or hesitation in the action of the pin on the crank arm. This resistance, in the repetitive movement required for a continuous sifting operation, can be somewhat tiring and will cause some degree of difficulty. The location of the lobe in this area makes a corresponding displacement of the pivot pin, which is mounted in the groove, and a corresponding increase of the effective torsion arm, which has been found to smooth and effectively facilitate the operation and effort required for the sieve manipulation. In other words, at the point of maximum resistance, the torsion automatically increases, canceling the hesitation or increase in resistance, which would normally be felt by the sieve operator. This sieve, due to its reciprocal movement during normal use, will include a return spring of the trigger as well as end limits. Other features and advantages of the invention will become apparent from the more detailed description of the invention discussed below. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of the inventive sieve, with the upper and lower seals separated from each other.; Figure 2 is a vertical cross-sectional view through the sieve, with both seals mounted, taken substantially in a plane passing along line 2-2 in Figure 1; Figure 3 is a cross-sectional view, similar to Figure 2, with the stamps removed and the trigger in its retracted position; Figure 4 is a bottom perspective detail of the sieve, with portions in section and separated for purposes of illustration; Figure 5 is a detailed perspective view, with separate parts, of several of the operation components, illustrating their overall relation with respect to the bottom screen; Figure 6 is a horizontal detail in cross section, taken substantially in a plane passing along the line 6-6 in Figure 2 and illustrating the pulse arm both fully extended, with its trigger in its relaxed position, as, in silhouette lines, partially retracted; Figure 7 is a detail in cross section, taken substantially in a plane passing along line 7-7 in Figure 3, with the trigger in its fully retracted position; and Figure 8 is an enlarged perspective detail, illustrating the manner of mounting the pivot trigger to the handle. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more specifically to the drawings, the screen 10 includes a cylindrical body 12, vertically elongate, hollow, preferably of a constant diameter for the main portion of its height upwardly from the lower edge 14 of support . This body 12 comprises the container for the flour or similar material to be sifted. In order to facilitate the introduction of the flour to the body 12 of the sieve, its upper portion 16 is flared outwardly and upwardly and terminates in an annular mouth 18, which may be provided with a slight internal lip, to which a seal overlapped 20 can be releasably coupled, as will be described later. The actual sieve for the flour or the like is made through the sieve 22 of the sieve, which forms the bottom or bottom wall of the body 12 of the container and is integrally formed therewith, in a slightly spaced relationship upward to the supporting edge lower 14, to define a chamber 24, immediately below the sieve 22 of the sieve, to receive selected operating components. Looking at Figure 4 in particular, in which a portion of the screen of the screen forming the bottom is illustrated in perspective, it will be appreciated that this screen has multiple openings, defined by concentric arcuate or annular ribs, spaced radially, divided into arcuate grooves in length substantially equal by radially extending ribs of variable length, the screen being preferably molded integral with the body. of the container. The sieve 10 includes a handle 26 rigid and preferably integral, at its upper end, with the inclined portion 16 of the body 12 of the container. The handle forms an arc outwardly and downwardly from this upper end attached to the lower end outwardly, spaced from the lower end of the container 12 and including a common bottom edge with the lower edge 14 of the body, to define a broad support base for the sieve. The handle 26 has in cross-section a substantially U-shaped configuration, open to the inside towards the body 12 of the container and has the lower end portion made rigid by the opposite extensions 28, which extend between the lower end portion of the handle 26 and the wall of the container. Such extensions 28 extend parallel to each other to define an operating channel 30 therebetween, as a partial guide for the trigger 32, which will be described in the following. The extensions, which are, in fact, coplanar continuations directed to the interior of the lower portions of the opposite sides 34 of the U-shaped handle 26, are furthermore made rigid by squaring-type shoulders 36, directed laterally outwards, which extend and join the adjacent portions of the body wall. The trigger 32, also of generally U-shaped configuration, is received between the opposite sides 34 of the handle 26 inwardly relative to this handle, for selective pivotal removal of the handle and outward extension thereof. The pivotal mounting of the trigger 32 is effected, see in particular Figure 8, by a pair of opposed short axes 38 projecting laterally on the opposite sides of the trigger 32, adjacent to its upper end. These axes 38 are received rotatably within openings 40, defining corresponding sockets, on the opposite sides 34 of the handle 26. In order to limit the extension of the pivotal movement of the handle 32, the short shafts 38 include a central waist portion, defined by opposed angular notches 42, which receive the opposing angular projections 44, which extend into the ferrules 40 receiving the corresponding axes. The angle of the projections 44 is smaller than the angle of the notches 32 of the corresponding axes. As such, the rotation of the axes 38 and thus the pivotal movement of the trigger 32, is allowed before the opposite axis portions, which define the grips, which engage the projections 44. This limited movement, which may be approximately of 15s, defines the range of movement of the trigger. Note Figure 1 for a scale illustration of this relationship. Looking at Figures 2 and 3, which illustrate the trigger in its fully extended and retracted positions, respectively, it will be seen that an appropriate compression spring 46 is received within the handle configured in U, which looks opposite, and the trigger, with the opposite legs of the spring in contact respectively against the turning portion of the handle and the return portion of the trigger under slight compression to provide a constant action of resilient orientation that forces the trigger to its forward relaxed position, as in Figure 2. The spring 46 is a return spring which, after manual compression of trigger 32 towards handle 26, will automatically return this trigger, which generates a reciprocal movement, as appropriate, in a sifting operation of the type involved. The illustrated spring 46 can be easily assembled by the introduction through the open lower ends of the handle and the trigger with the apex of the spring, that portion between its compressible legs, being generally in alignment with the short axes and with the lower end of one of the legs of the spring engaged in a small retainer backrest 48 at the lower end of the front wall of the trigger 32. As will be appreciated, other forms of return springs may be used. The trigger 32 is intended as a manual resource for reciprocally activating the operative components that stimulate and increase the movement of the flour or the like through the bottom 22 of the sieve. These components include a rotor 50, having a central hub 52, with integral blades 54 projecting radially extending from the hub, preferably at equally spaced points completely around it. The diameter of the rotor 50, at the periphery defined by the outer ends of the blades 54, is slightly smaller than that of the bottom 22 of the sieve for effective sweeping of the blades over the entire usable surface of the bottom, during operation, as will be explained subsequently. To increase the effectiveness of the blades 54 in directing and in some cases forcing the flour or the like through the openings in the bottom of the sieve, the blades, as suggested in the drawings, may be of an oval cross-section or slightly elliptical, for its entire length. The rotor hub overlaps the axial central portion of the bottom 22 and its internal annular area, defined by a ring 56 that provides rigidity. In order to achieve a pulse ratio of the rotor 50 with the remaining operating components, the rotor includes a rectangular split tab 58, integral with the hub 52 and axially dependent therefrom, through the central opening 60 in the bottom 22 of the screen, defined by the inner ring 56. The tab 58, as seen better in Figure 5, includes parallel legs, which are provided with lower end portions, which snap, adapted for contact with a corresponding socket, in a known manner. A crank wheel 62 is placed immediately below the bottom 22 of the sieve, coaxially with it. This crank wheel 62 includes a cylindrical crank hub 64, central, projecting upwards, with a smooth periphery surface and a central rectangular cap 66, which opens upwards. This bushing 66 receives the tab 58 of the rotor and, as seen in FIGS. 2 and 3, includes internal backs to which the split locking ends of the tab are joined for a snap-fit of the rotor 52 on the wheel 62 of crank. The rectangular configuration of the tongue 58 and the bushing 66 provides a direct drive of rotation of the rotor in response to the rotation pulse of the crank wheel 62. This crank wheel 62 includes a crank arm 62, which extends radially outwardly. , having an elongated pin slot 70. The crank wheel 62 is completed by an integral, elongated, arched projection 72 adjacent to the outer periphery of the wheel, remote from the crank arm 68 and a height of approximately half that of the crank hub 64, for the sliding arm with the lower surface of the bottom 22 of the screen, whereby it acts in the form of a spacer between the cisco portion of the crank wheel 62 and the bottom of the screen to accommodate an elongated pulse arm 74. The arm of Impulse 75 is an integral extension of a relatively wide elongated trigger bar or plate 76 extending from the pulse arm 74 to an outer end, which is integral with the lower portion of the trigger 32. This bar 76 of The trigger is slidably received within the channel 30 defined between the handle and the body of the container. The channel 30, see Figures 3 and 4 in particular, opens directly through the side wall of the body 12 of the container into the underlying chamber 24, to allow free reciprocating sliding movement of the trigger bar 76 and the arm of the trigger. integral pulse 74. This pulse arm 74 is received in a relationship superimposed on the crank wheel 62 and includes a pivot pin 78, which is received rotatably within the elongated slot 70 of the crank arm, whereby the Reciprocal movement of the impulse arm 74 through manipulation of the trigger 32, will effect a corresponding rotation of the crank wheel 62 and the broken 50 with blades with it. This crank wheel 62, supported by the rotor 50, effectively supports the pulse arm 74 with the space between the disk of the crank wheel and the bottom 22 of the overlapping sieve, defined by the spacer or projection 72, which - like the desired sliding movement of the impulse arm 74. As suggested in Figures 6 and 7, the projection 72, or more particularly its opposite ends, can be used as stops defining the end positions of the impulse arm 74. As an additional resource to define the relaxed position of the trigger 32, a stop projection 80 can be formed integrally on the trigger bar 76 for contact against the external surface of the container body 12, as seen, for example, in Figures 1 and 2 Turning now more specifically to the impulse arm 74, it is particularly significant, in achieving the uniform and consistent desired operation of the sieve, that the relationship between the pulse arm 74 and the crank 62 and thus also the rotor 50, be such as to supply a transferuniform and consistent, of the impulse force between them, throughout the range of movement of the trigger and without requiring the use of excessive manual pressure or excessive return spring pressure. This is achieved by specifically defining the longitudinal inner edge 82 of the impulse arm 74 as the cam edge. This cam edge 82 engages the hub 64 of the crank wheel, which acts as a cam follower and is oriented slightly against its peripheral surface by the inherent resilient resilience of the pulse arm 74, through a range of longitudinal movement of the arm 74. This surface or cam edge 82 has an effective length by the arm 74, ie that length which is at the edge in contact with the hub 64 through the entire interval of longitudinal reciprocal movement of the arm 74. In order to achieve the desired uniform operation, which allows the use of a constant manual pressure to pull the trigger and a resulting constant action of the spring, to return this trigger, the cam edge 82 is centrally between the ends of its length effective, provided with a central lobe 84, with gradually tapering sides. This lobe 84 is configured to maintain constant contact with the outer peripheral surface of the hub 64 as the impulse arm 74 reciprocates through the central length of its movement and will make a constant, laterally deflected outward increase, which it places the arm 74 as this arm moves and rotates the crank wheel through the central critical zone of movement, thus accommodating what will normally be an increased resistance to or hesitation in movement. This hesitation is avoided by the constantly increasing torsion resulting from the lateral displacement of the impulse arm 74 relative to the axis of the crank wheel 62. The arm, through the lobe 84, moves laterally outwardly relative to the crank wheel, as the central zone approaches both the retraction movement and the extension of the impulse arm 74. Conform to the apex of the central lobe 84 is brought into contact with the peripheral surface of the crank hub 64, the pin 78 of the driving arm, confined by the slot, is at its maximum lateral distance from the hub 64 and the central axis of the crank wheel 62. Thus, the maximum torque is achieved to transfer the force between the arm 74 and the wheel 62. This, in turn, allows the passage of the arm and the movement of the crank wheel with minimal effort on the part of the user of the wheel. device in the manual action of the trigger and the return spring in the reciprocal movement of return of the trigger and the impulse arm. The use of the cam rim and the uniformity of its operation substantially reduces the operating stresses in the impulse arm. The lateral flexion of the substantially rigid impulse arm, effectively controlled by the cam edge, allows the uniform movement of the pin 74 of the pulse arm without the slot 70 of the crank arm, to increase the operation without the restriction sought, particularly in those situations in which the trigger is manipulated repeatedly. Similarly, the increased efficiency of the operating relationship between the pulse arm 74 and the return wheel 62 allows the use of a lighter or weaker return spring 46. This is also essential for the effective use of the sieve in that the manual pressure to overcome the resistance of the spring is reduced, allowing a more uniform and effortless manipulation of the trigger. All these factors contribute significantly to a convenient, efficient and practical kitchen utensil. Referring again to Figures 1 and 2, and the possibility of storing the sieve 10 with remaining food products therein, the upper seal 20 includes an internal dependent flange 90., which is received inside the open mouth, directed upwards, of the body 12 of the container and retained in a frictional and releasable manner by contact with a lip directed slightly inward at the wedding rim or rim 18. This relationship will be noted better in Figure 2. The seal 20 is also configured with a central, cylindrical 92 dome projecting upwards, with a concave upper panel 94, directed upwards. This dome 92 has a peripheral wall 96 which is adapted for telescopic frictional reception and contact within the lower portion of the wall of the body 12, which defines the chamber 24 for the components of the impulse arm and the crank wheel, under the bottom sieve 22. When so assembled, again with reference to Figure 2, it will be appreciated that the dependent flange 90 provides an effective wide stable base, while the lower end of the sieve body is sealed against any undesired discharge through the sieve screen. As suggested in Figures 1 and 2, the assembly can actually include two seals 20 for a complete closure of the container body. Alternatively, a single seal can be supplied for selective use in closing the upper part of the container, such as, for example, in the sifting of particularly fine or powdered materials, or closing the bottom of the container to temporarily stop the discharge.
It is intended that all the components of the sieve of the invention be formed of suitable synthetic resinous materials, compatible with food, in each case incorporating the degree of stiffness and resilient flexibility required for the desired movement. In this aspect, note, as an example, Figure 3, in which the trigger bar 76, while having sufficient rigidity to longitudinally transfer the forced movement of the trigger 32, is capable of a slight degree of lateral flexion to accommodate the inclination inherent upward of its end in contact with the trigger. A similar relationship exists between the force that transmits the stiffness of the impulse arm 74 and the flexible lateral resilience required to accommodate the desired uniform lateral movement and the torsional increase and the corresponding subsequent decrease. The foregoing is illustrative of the characteristics of the invention and, in particular, of the novel concept of increasing the effective operation of a manual sieve, varying the torsion as a resource to reduce the effort required to achieve uniform operation. While only one embodiment illustrating the features of the invention has been presented, it will be appreciated that other embodiments, as they fall within the scope of the following claims, are also considered within the scope of the invention.