Field

[0001 ] The present invention relates to a toaster. Background

[0002] A popular form of commercial toaster, such as used in hotel breakfast buffets and cafes and restaurants, i a conveyor toaster. Conveyor toasters utilise an endless conveyor belt formed of wires thai con vey slices of bread to be toasted through a toasting cavity wi th an upper heating element, arranged above the conveyor belt, and a lower heating element, typically arranged in the centre of the conveyor bel t, to simultaneously toast the upper and lower surface of the bread. Whilst the upper heating element may provide even toasting of the upper surface of each slice of bread, the lower hearing element is impeded by wire elements of the conveyor belt that are in direct contact with the lower surface of the bread, causing a shadowing effect on the lower surface of the bread and thereby preventing even toasting.

[0003] The use of a conveyor belt also requires bearings and belt tensioning mechanisms that must operate at temperatures of up to 300 ^e C, Servicing of these mechanisms, and the lower heating element which is typically positioned in the centre of the belt system, is typically very difficult due to lack of access of the relevant components from the exterior of the toaster.

Currently available conveyor toasters are also typically relatively noisy, as a result of clicking and creaking forms of noise generated by the typically urjlubricated wires of the conveyor belt and drive motor, which is typically a relatively noisy voltage controlled DC drive motor. This form of motor is also often unreliable.

[0004] Other forms of motor have also been utilised with conveyor toasters, with varying success. Brushless DC and AC speed controlled motors are being utilised, however these are typically quite expensive and require cooling to protect the delicate electronics of the electronic controls that are required. Voltage controlled shaded pole motors have also been utilised, however these motors typically lose torque when speed is reduced, which can lead to stalling of the conveyor belt at low drive speeds. The use of conveyor belts requires a speed controller device to enable adj ustment of the conveyor belt speed to accommodate different types of bread 9 and individual user preferences, to ensure that bread is toasted to the desired level. Conveyor toasters are also typically difficult to clean or to remove any bread that has been jammed inside the toasting cavity.

Summary of Invention

[0005] In a first aspect the present invention provides a toaster comprising:

a) a housing defining a toasting cavity extending between an upstream toasting cavity inlet and a downstream toasting cavity outlet; b) a conveyor mechanism mounted in said toasting cavity and longitudinally extending from adjacent said toasting cavity inlet to adjacent said toasting cavity outlet, said conveyor mechanism comprising:

(i) a first rack having a plurality of longitudinally extending and laterally spaced first rack elements, an upper surface of each of said first rack elements defining a first plane; and

(it) a second rack having a plurality of longitudinally extending and laterally spaced second rack elements interposed between said first rack elements, an upper surface of each of said second rack elements defining a second plane; c) an upper heating element arranged in said toasting cavity above said conveyor mechanism; d) a lower heating element arranged in said toasting cavity below said conveyor mechanism; and e) a drive mechanism configured to drive said second rack along a cyclic path having a conveying phase in which said second plane is disposed above said first plane and said second rack elements are displaced downstream and a return phase in which said second plane is disposed beneath said first plane and said second rack elements are displaced upstream.

[0006] h a preferred form, said first rack is fixed in relation to said housing. [0007] In a prefened form, said housing comprises a lid displaceable between a closed position defining an upper wall of said toasting cavity and an open position providing access to said toasting cavity.

[0008] Typically, said tipper element is fixed in relation to said lid.

[0009] In a preferred form, at least some of said first and second rack elements are each provided with a detent arrangement at an upstream end portion of the respective rack element for arresting disp lacement of bread fed into said toasting cavity through said toasting cavity inlet

[0010] In a preferred form, each of said first and second rack elements comprises a wire with said upstream end portion of each of at least some of said first and second rac k element being wound into a spring form to define said detent arrangement.

[003 1 ] Typically, each of said first and second racks comprises a rack frame with said wires being detachable mounted to the respective said rack frame.

[0012] Preferably, said first and second racks are removable from said housing with said lid in said ope osition.

[0013] In a preferred form, said toaster further comprises an inlet guide for guiding bread through said toasting cavity inlet into said toasting cavity, said inlet guide being upwardly inclined relative to said first rack.

[0014] In a preferred form, said toaster further comprises a toast collection cavity arranged beneath said toasting cavity and communicating with said toasting cavity through said toasting cavity outlet for passing toasted bread into said collection cavity.

[0015] Typically, said drive mechanism is user adjustable to adjust a stroke of said conveying phase.

[0016] Preferably, said stroke is adjustable by way of a control, such as a control knob, accessible from an exterior of said housing. [0017] In a preferred form, said drive mechanism comprises a motor and gear mechanism, said drive mechanism being configured to operate said motor at a constant speed with said gear mechanism being user adjustable to adjust said stroke of ^" said conveying phase.

[0018] In one form, said motor is a constant speed shaded pole motor.

[001 ] m a preferred form, said gear mechanism comprises a lifting arrangement configured to cyclically lift and lower said second rack and a conveying arrangement arranged to cyclically longitudinally displace said second rack in said conveying and return phases, wherein said conveying arrangement is operatively coupled to said lifting arrangement,

[0020] In a particular preferred form, said lift arrangement is driven by said drive motor and said conveying arrangement is driven by said lifting arrangement,

[0021 ] In one embodiment, said lift arrangement comprises a lift earn operatively coupled to said motor to be rotationally driven by said motor, a cam follower engaging said lift cam and a lift member attached to said cam follower, said lift member being restrained against longitudinal displacement such that, in use, said lift cam drives said lift member cyclically i a substantiall vertical direction.

[0022] Typically, said conveying arrangement is mounted to said lift arrangement and restrained against displacement relative to said lift arrangement in a substantially vertical direction, such that, in use, said conveying arrangement is driven cyclically in a substantially vertical direction with said lift member.

[0023] In one embodiment, said conveying arrangement comprises a cycloid ring gear, a cycloid planet gear mounted on a shaft driven by said motor about a circular path with said cycloid ring gear such that said cycloid planet gea is driven about said cycloid ring gear, a drive pin mounted on said cycloid planet gear offset from said shaft and a conveying member, said conveying member and said drive pin together defining a Scotch yoke configured to convert cyclical displacement of said drive pin to cyclic longitudinal displacement of said conveying member.

[0024] Preferably, said drive mechanism further comprises an adjustment mechanism configured to adjust a stroke of longitudinal displacement of said conveying member. [0025] I on embodiment, said adjustment mechanism is configured to pivotaliy displace said cycloid ring gear and thereby rotate a path of travel of said drive pin.

[0026] In one form, said adjustment mechanism comprises a rotatably mounted control shaft having a gear engaging an adjustment rack gear operativeiy coupled to said cycloid ring gear to pivot said cycloid ring gear upo displacement of said adjustment rack gear.

Brief Description of Drawings

[0027] Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings wherein:

[0028] Figure 1 is a front isometric view of a toaster according to a first embodiment;

[0029] Fi gure 2 is a front isometric view of the toaster of Figure 1 with the lid in the open position;

[0030] Figure 3 is a front isometric view of the toaster of Figure 1 with the lid in the open position and the first rack removed;

[0031] Figure 4 is a front isometric view of the toaster of Figure 1 with the lid in the open position and the first and second racks removed;

[0032] Figure 5 is a front isometric view of the toaster of Figure 1 with the lid open, the lower heating element in a lifted position and the crumb tray removed;

[0033] Figure 6 is a rear isometric view of the first rack assembly of the toaster of Figure 1;

[0034] Figure 7 is a rear isometric view of the first rack assembly of Figure 6 with the first rack in a partially installed position;

[0035] Figure 8 is a rear isometric view of the second rack assembly of the toaster of Figure 1;

[0036] Figure 9 is a rear isometric view of the second rack assembly with the second rack in a partially installed position; ό

[0037] Figure 10 is a rear isometric view of the toaster of Figure 1 with the lid and first element rack removed;

[0038] Figure 1 1 is an enlarged fragmentary view of Detail A of Figure 10, depicting the first rack assembly mounting to the drive motor;

[0039] Figure 12 is a fragmentary isometric vie w of the conveying mechanism of the toaster of Figure 1 ;

[0040] Figures 13 a to 13f are each side elevation views of the conveying mechanism of Figure 12 new phases and cycle of motion of the second rack of the conveying mechanism.

[0041] Figures 14 to 18 are each fragmentary perspective views of the conveying mechanism of Figure 12 sequentially depicting the conveying of a piece of bread along the conveying mechanism.

[0042] Figure 19 is a fragmentary isometric view of a conveying mechanism with an alternative form of first and second rack elements;

[0043] Figure 20 is an isometric view of the dri ve mechanism of the toaster of Figur 1 in a fully assembled state;

[0044] Figure 21 is an isometric view of the drive mecha ism of Figure 20 in a partially assembled state;

[0045] Figure 22 is an isometric view of the drive mechanism of Figure 20 in a further partly assembled state;

[0046] Figure 23 is an isometric view of the drive mechanism of Figure 20 in a still further partly assem bled sta te;

[0047] Figure 24 is an isometric view from the rear of the lift cam and sun gears of the drive mechanism of Figure 20; [0048] Figure 25 is an isometric view of the drive mechanism of Figure 20 in another partly assembled state;

[0049] Figure 26 is an isometric view from the rear of the lift cam, sun gears, cam follower bearing and lif member of the drive mechanism of Figure 20;

[0050] Figure 27 is an isometric view of the drive mechanism of Figure 20 in a still further partly assembled state;

[0051] Figure 28 is an isometric view of the drive mechanism of Figure 20 in a yet further partly assembled state;

[0052] Figure 29 is an isometric view of the drive mechanism of Figure 20 in another further partly assembled state;

[0053] Figure 30 is an isometric view of the drive mechanism of Figure 20 in yet another further partly assembled state;

[0054] Figure 31 depicts the partly assembled arrangement of Figure 30, particularly depicting a maximum stroke of the drive pin;

[0055] Figure 32 depicts the partly assembled arrangement of Figure 30, particularly depicting a minimum stroke of the drive pin;

[0056] Figure 3.3 is a side elevation view of the drive mechanism of Figure 20 depicting a maximum stroke cycle;

[0057] Figure 34 is a side elevation view of the drive mechanism of Figure 20 depicting a minimum stroke Cycle;

[0058] Figure 35 is a front isometric view of a toaster according to a second embodiment; [0059] Figure 36 is an isometric view of an alternate dri ve mechanism in a fully assembled state; [0060] Figure 37 is an isometric view of the drive mechanism of Figure 36 in a partially assembled state;

[006 ] Figure 38 is an isometric view of the drive mechanism of Figure 36 in a still further partly assembled state;

[0062] Figure 39 is an isometric view from the rear of the lift cam and bevel gear of the drive mechanis of Figure 36;

[0063] Figure 40 is a partially sectioned isometric view of the drive mechanism of Figure 36 in another partly assembled state;

[0064] Figure 41 is an isometric view of the drive mechanism of Figure 36 in the partly assembled state of Figure 40;

[0065] Figure 42 is an isometric view from the rear of the lift cam, bevel gear, cam follower bearing and lift member of the drive mechanism of Figure 36.

Description of Embodiments

[0066] Referring firstly to Figures 1 to .5 of the accompanying drawings, a toaster according to a first embodiment has a housing 100 which includes a housing body 110 and a housing lid 120 that is pivotably mounted to the rear of the housing body Ϊ 10 so as to be displaceable between a closed position, as show n Figure 1, and an open position, as shown in Figure 2. A catch may be provided to hold the lid 120 in the closed position. The housing body 1 10 has a pair of opposing housing side walls 111, a removable housing rear wall 112 and. a control, enclosure 113 at the upper from of the housmg body 110, As best shown in Figures 4 and 5, a removable crumb tra 1 14 is removably mounted within the housing body 1 10. The crumb tray 1 14, housing side walls 1 1 1 , housing rear wall 1 12 and control enclosure 1 13 together define a toasting cavity 1 15. The housing lid 1 0, when in the closed position, defines the upper wall of the toasting cavity 115. The toasting cavity extends between a toasting cavity inlet 1 16, defined between the housing lid 120 and the drive enclosure 1 13 , and a toasting cavity outlet 1 7 adjacent the housing rear wall 1 12. [0067] An upper heating element .1 18 is provided in the top of the toasting cavity 115, here being mounted on the underside of the housing lid 120, as best depicted in Figure 2. A lower heating element 1 19 is mounted in the bottom of the toasting cavity 115, directly above the crumb tray 1 14, as best depicted in Figures 4 and 5. As best depicted in Figure 5, the lower heating element 119 is pivotally mounted to the housing side walls 1 1 1 so as to provide easy access for complete cleaning of the interior of the housing body .1 1 .

[0068] A toast collection cavity 121. is arranged beneath the toasting cavity 1 15, and

communicates with the toasting cavity via the toasting cavity outlet 11 . The toast collection cavity 121 has a concavely curved floor 122 extending downwardly from the toasting cavity outlet 1 17 to the front of the toast collection cavity 121 at the front of the toaster.

[0069] Referring to Figure 2, a conveyor mechanism. .130 is mounted in the toasting cavity . 15 and longitudinally extends between a conveyor upstream end 131 located adjacent to and below the toasting cavity inlet 1 16 and a conveyor downstream end 132 located adjacent the toasting cavity outlet 1 17, The conveyor mechanism 130 is mounted in the toasting cavity 1 15 between the upper and lower heating eleme ts 11 S, 1 19 such that the upper heating element 1 18 is arranged above the conveyor mechanism 130 and the lower heating element 119 is arranged below the conveyor mechanism 130. The conveyor mechanism 130 comprises a first rack assembly 140 and a second rack assembly 160.

[0070] The first rack. assembly 140, depicted in isolation in Figure 6, comprises a first rack mount 141 and a first rack 150. An inlet guide 145 is also formed with the first rack assembly 140, here being integrally formed with the first rack 150 and upwardly inclined relative to the first rack 150.

[0071] The first rack mount 141 has opposing baffle plates 142 that are fixedly mounted against the housing side wails 1 1 1 within the toasting cavity 1 .15, The baffle plates 142 are provided with a pair of longitudinally extendin downstream mounting slots 143 extending longitudinally from the downstream (rear) end of each of the baffle plates 342 and a pair of downwardly extending upstream mounting slots 144 extending downwardly from adjacent the upstream (front) end of each of the baffle plates 142. A compression spring 148 is mounted in the upstream end of the each of the downstream mounting slots 143. [0072] The first rack 150 has a peripheral first rack frame 151 , a pair of downstream mounting pins 152 laterally projecting from the first rack frame 151 adjacent the downstream end of the first rack frame 151 , and a pair of upstream mounting pins 153 laterally projecting from the first rack frame 15 ! adjacent the upstream end of the first rack frame 151. The first rack 1 0, together with the integrally formed, inlet guide 145, is mounted in the first rack mount 141 by inserting the downstream mounting pins 152 into the downstream mounting slots 143. as depicted in Figure 7, and then displacing the first rack 150 forward, against the springs 148, until the upstream mounting pins 153 are aligned with the upstream mounting slots 144. The first rack 150 is then pushed downwards so as to push the upstream mounting pins 1 2 into the upstream mountin slots 144. The springs 148 urge against the downstream mounting pins 152 so as to firmly lock the first rack 150 (and inlet guide 145) into place. As will be appreciated, the first rack 150 is thus fixed in the housing 100. The first rack 150 is removable by pushing the first rack 150 forward against the action of tire springs 148 and upwardly to first remove the upstream mountin pins 153 from the upstream mounting slots 1 4 before displacing the first rack 150 rearwardly to remove the downstream mounting pins 152 from the downstream mounting slots 143 . The first rack 1 0 may then be removed from the housing .100 with the lid 120 in the open position.

[0073] The first rack 150 has a plurality of laterally spaced first rack elements 155 longitudinally extending between upstream and downstream first rack mounting fingers 156, 157 at opposing ends of the first rack frame 151, corresponding to the conveyor upstream and downstream ends 131, 132. i the arrangement depicted, seven laterally spaced first rack elements 155 are provided, in the arrangement depicted, each of the first rack elements 155 is in the form of a steel wire. The upstream end portion of each of the first rack elements 1.55 is wound into the form of a spring 158 to define a detent arrangement for arresting displacement of bread inserted into the toasting cavity 115 through the toasting cavity inlet 1 16, as will be further described below. The upper part of each winding of the spring 158 forms a detent to engage the bread. Each of the first rack elements 155 is detachably mounted on the first rack mounting fingers 156, 157 for simple replacement of damaged first rack elements 155, it is envisaged, however, that the first rack elements 155 may be permanently fixed to the first rack frame 1 1. Spring tension of the spring .158 of each first rack elemen t 155 retains each first rack element 155 in place and maintains tension in each first rack element 155. I I

[0074] As described above, the inlet guide 145 is here integrally formed with the first rack 150, although it is envisaged that the inlet guide 145 might be formed separate to the first rack 150 and separately mounted w thin the housing body 1.10. As shown in Figure 1, the inlet guide 145 extends from the upstream end of the first rack 150 through the toasting cavity inlet 3 16 and forms an inclined ramp for feeding bread onto the conveying mechanism 130 at the conveyor upstream end 131. The inlet guide 145 is in the form of a guide rack, formed with a plurality of laterally spaced wires 146, fixed to an inlet guide frame 147 that is formed with the first rack frame 1 1. Additional intermediate wires (not depicted) may be located between each pair of adj acen t wires 146 of the inlet gu i de 145.

[0075] The second rack assembly 160. depicted in isolation in Figures 8 and 9, comprises a second rack mount 161 and a second rack 170. The second rack mount 161 has a cross-member 62 located at the upstream end of the second rack mount 161 and a pair of opposin carrier arms 163 that extend to the downstream end of the second rack mount 1.61. A pair of upstream rack mounting brackets 164 are provi ded at the upstream end of the carrier arms 163 , w it a pair of downstream rack mounting brackets 165 being provided at the downstream end of the carrier arms 163. Adjustment screws 167 on each of the carrier arms 163 allow for adjustment of the level of the upstream and downstream mounting brackets 164, 165, to ensure the second rack 170 is level relative to the first rack 150.

[0076] The second rack 170 has a second rack frame 171 with a pair of upstream mounting pins 172 laterally projecting from the second rack frame 1.71 adjacent the upstream end of the second rack frame 171, and a pair of downstream mounting pins 173 laterally projecting from the second rack frame 171 adjacent the downstream end of the second rack frame 171 . The second rack 1.70 is mounted in the second rack mount 161 by inserting the upstream mounting pins 172 into the upstream mounting brackets 164, as depicted in Figure 9, and then displacing the second rack 170 forward., against springs 1 6 that act between the cross-member 162 and the second rack frame 171 to urge the second, rack 170 rearwardly. The second rack 170 is then pivoted about the upstream mounting pins 172 until the downstream mounting pins 1 73 are engaged with, the downstream mounting brackets 1 5, with the action of the springs 1 6 firmly locking the downstream mounting pins 1 3 within the downstream mounting brackets 165. The second rack 170 is removable by pushing the second rack 1 70 forward against the action of the springs 166 and upwardly to first remove the downstream mounting pins 173 f om the downstream mounting brackets 165 before displacing the second rack 170 rearwardly to remove the upstream, mounting pins 172 from the upstream mounting slots 164. The second rack 170 may then be removed from the housing 1.00 with the lid 120 in the open position. The second rack 170 is, however, mounted beneath the first rack 150, so the first rack 1 0 must first be removed to provide access to the second rack 170. An alternative arrangement of the mounting brackets and mounting pins is also envisaged that mounts the second rack by first inserting downstream mounting pins into downstream mounting brackets and then pivoting the second rack about the downstream mounting pins until the upstream mounting pins engage the upstream mounting brackets.

[0077] The second rack 170 has a plurality of laterally spaced first second rack elements 175 longitudinally extending between upstream and downstream second rack mounting fingers 1 76, 177 at opposing ends of the second rack frame 171 , corresponding to the conveyor upstream and downstream ends 131, 132. In the arrangement depicted, eight laterally spaced second rack elements 175 are provided. In the arrangement depicted, each of the second rack elements 175 is of identical form to the first rack el ements 155, particularl y being in the form of a steel wire with the upstream end portion of each of the second rack elements 175 being wound into the form of the spring 178 to define a detent arrangement for arresting displacement of bread inserted into the toasting cavity 1 15 through the toasting cavity inlet 1 16. Each of the second rack elements 175 is removably mounted on the second rac mountin fingers 176, 177 for simple replacement of damaged second rack frame elements 175. As with the first rack elements, spring tension of the spring 178 of each second rack element 1 5 retains each first rack element 175 in place and maintains tension in. each first rack element 175.

[0078] The second rack mount 161 is mounted in the toasting cavity 1 15 by w ay of a drive arm 360 secured to the cross-member 162. The drive arm 360 forms part of a dri ve mechani sm 200 mounted within the control enclosure 113, a depicted in Figures 10 and 1 1 . The drive mechanism 200 drives the second rack 1.70 along a cyclic path which will be described below.

[0079] As best depicted in Figure 5, when the first and second rack mounts 141,161 are installed in the toasting cavity 1 1 5, the carrier arms 163 extend along and adjacent to the baffle plates 142. The second rack mount 161 is mounted in the toasting cavity 115 beneath the upstream and downstream mounting slots 144, 143 tonned in the baffle plates 142 such that, when the first and second, racks 150, 170 are installed, the second rack mount 161 is mounted beneath the first rack 150. Figure 12 depicts a segment of the first and second racks 150, 170 when, instal led, showing the second rack elements 175 interposed between the first rack elements 155. The configuration of the first and second rack frames 151. { 71 is such that the second rack elements 175 may be raised and lowered between the first rack elements 1.55 between a lowered position in which a second plane defined by the upper surface of each of the second rack elements 175 is disposed below a first plane defined by the upper surface of each of the first rack elements 155, and a lifted position in with the second plane is disposed above the first plane. This is particularly achieved in the embodiment depicted by way of the configuration of the upstream and downstream fingers 156, 157 of the first rack frame 151 mounting the first rack elements 155 and the configuration of the upstream and downstream fingers 176, 177 of the second rack frame 171 mounting the econd rack elements 175.

[0080] Cyclic displacement of the second rack 170 will no be described with reference to Figures 13a to 13f _s which depict the first and second racks 150, 170 of the conveying mechanism 130 with the second rack 170 shown i different phases of the cycle through which it is driven by the dri ve mechanism 200. A shown by the sequence of arro ws at the left of each of Figures 3 a to 13f, the cyc lic path of motion of the second rack 170 is substan tially rect ilinear, defined by the sequential phases of a conveying phase, lowering phase, return phase and lifting phase. Figure 13a depicts the second rack 170 at the end of the lifting phase begimiing of the conveying phase. At this point, the second rack 170 is in a lifted position in which the second plane, defined by the upper surface of each of the second rack elements 175, is disposed above the first plane, defined by the upper surface of each of the first rack elements 155. The second rack 170 is also in an upstream position with the upstream end of the second rack 170 located upstream of the upstream end of the first rack 150. As depicted in Figure 13b, the second rack 170 is then driven through the conveying phase, where it is displaced downstream whilst in the lifted position. At the end of the conveying phase/beginning of the lowering phase, as depicted in Figure 13c, the second rack 170 remains in the lifted position and is at a downstream position where the downstream end of the second rack I 70 is downstream of the downstream end of the first rack 150. The second rack 170 is then driven through a lowering phase in which the second rack 170 is lowered to a lowered position, as depicted in Figure 1 3d, where the second plane, defined by the upper surface of the second rack elements 175, is disposed below the first plane, defined by the upper surface of each of the first rack elements 155. As depicted in Figure 13e, the second rack 170 is then driven through a return phase in which the second rack 170 is retained in the lowered position and driven to the upstream position as depicted in Figure 12f at the end of the return phase. The second rack 170 is then dri ven through a lifting phase in which the second rack 170 is lifted to the lifted position, as depicted in Figure 13a, This cycle is repeated whilst the drive mechanism 200 is operating.

[0081] Operation of this cyclic displacement of the second rack 170 in conveying a piece of bread 50 along the conveying mechanism 130 through the toasting cavity 1 15 will now be described with reference to Figures 14 through 18, which depict the pat of a piece of bread 50 being fed onto the conveying mechanism 1.30 in the toasting cavity 1 15 via the inlet guide 145. Only one first rack element 155 and one second rack element 175 are shown in each of these figures for clarity.

[0082] Figure 14 depicts the second rack element 175 at the beginning of the return phase (equivalent to the position shown in Figure 13d) with the second rack element 175 i the lowered position. A piece of bread 50 sliding down the inlet guide 145 engages the spring 158 of the first rack element 155, thereby arresting the slide of the piece of bread 50. Specifically, the lower edge of the piece of bread 50 rests between adjacent windings of the spring 158. This prevents the piece of bread 50 from rapidly advancing part-way along the conveying mechanism 130 under the action of gravity, instead ensuring the piece of bread is conveyed along the entire length of the toasting cavi ty 115 at a constant speed under the controlled action of the conveying .mechanism 1 0. The second rack element 175 is driven upstream along the return phase and then lifted in the lifting phase, engaging the lower edge of the piece of bread 50 as the upper surface of the second rack element 175 lifts to the plane of the upper surface of the first rack element 1 5, as depicted in Figure 15. As the second rack element 175 continues to be lifted in the lifting phase, the upper surface of the second rack element 175, particularly the spring 178, Sifts above the upper surface of the first rack element 155, l ifting the piece of bread 50 w ith the second rack element 175 off the first rack element 155. as depicted in Figure 16. Subsequent driving of the second rack element 1.75 downstream through the conveying phase conveys the piece of bread 50 downstream wi th the second rack element ί 75. The second rack element 175 is the lowered in the lowering phase and the piece of bread 50 is re-engaged with the first rack element 155 as depicted in Figure 17.

[0083] The distance that the piece of toast 50 has been moved along the first rack element 155 in this single cycle of movement of the second rack element 175 is equal to the stroke of the conveying phase of the second rack element 175. Cyclic movement of the second rack element .175 is continued, again lifting the piece of bread 50 from the first rack element 155 in the nex t lift phase and further conveying the piece of bread 50 further downstream i n the successive conveying phases. As the upper edge of the piece of bread 50 passes off the inlet guide 145 and onto the upstream end of the conveyor mechanism 130, the piece of bread 50 lies flat on the conveying mechanism 130, as depicted in Figure 18.

[0084] With each successive cycle of displacement of the second rack element 175, the piece of bread 50 is picked up by the second rack element 175 and conveyed downstream a distance equal to the stroke of the conveying phase. The piece of bread 50 is thus conveyed along the conveying mechanism 130 through the toasting cavity 1 15, where the upper and lower hearing elements 1 1 8, 1 1 toast the upper and lower surfaces of the piece of bread 50. Once the piece of bread 50 reaches the conveyor downstream end 132, it passes through the toasting cavity outlet 17 under the action of gravity along the curved floor 122 of the toast collection ca vity 121. The degree of toasting of die piece of bread 50 is determined by the speed of the conveying

mechanism. This is determined by the cycle time of the cyclic displacement of the second rack elements 175 and the stroke of the conveying phase of the second rack elements 175. As will be discussed in further detail below, the drive mechanism 200 is adjustable to adjust the stroke of the conveying phase, thereby allowing adjustment of the degree of toastin wit hout adj usting the cycle time of the cyclic displacement of the second rack elements 1 5.

[0085] Figure 1 depicts the first and second racks 150, 170 with alternate forms of first and second rack elements 155% 175'. The upstream end portions of the alternate first and second rack elements 155', 175' are provided with an alternate form of detent arrangement in the form of serrations 158', 178' formed in the upper surface of each of the first and second rack elements 155 175'. It is envisaged that the detent arrangements may also take other forms that will arrest displacement of the bread as it passes onto the conveying mechanism 130 from the inlet guide 145.

[0086] The drive mechanism 200 is depicted in a fully assembled form in Figure 20, and in various states of disassembly in Figures 21 to 30.

[0087] Referring firstly to Figure 20 _s the drive mechanism 200 comprises a motor 210, a gear mechanism 300 and an adjustment mechanism 230. The gear mechanism 300 comprises a lifting arrangement 310 that is configured to cyclically lift and lower the second rack 170, through the lifting and lowering phases, and a conveying arrangement 350 that is configured to cyclically longitudinally displace the second rack 170 in the conveying and return phases. The conveying arrangement 350 is operatively coupled to the lifting arrangement 310, Specifically, die motor 210 directly drives the lifting arrangement 310, converting rotational output of the motor 210 into a reciprocating substantially vertical motion output. The lifting arrangement 310 also provides rotational output which is converted by the conveying arrangement 350 into a reciprocating longitudinal motion which is transferred directly to the second rack by way of the drive arm 360 of the conveying arrangement. The reciprocating substantially vertical motio output of the lifting arrangement 310 provides reciprocating substantially vertical motion of the conveying arrangement 350, which is in turn transferred to the second rack 170 by way of the drive arm 360.

[0088] The motor 2 0 and vaiious elements of the lifting arrangement 3.10 are depicted i n Figures 23 t 27 at successive stages of assembly of the lifting arrangement 310.

[0089] Firstly referring to Figure 21 , the motor 210 is in the form of a constant speed motor., here specifically in a form of constant speed shaded pole motor. The motor 210 rotational! y drives a motor output shaft 211 that is machined in t he form of a helical gear. The motor 210 also drives a fan 212 that assists in coolin of the motor 210.

[0090] The lifting arrangement 310 includes a primary reduction gear 3 1 1 that is rotationally driven by the output shaft 211. The primary reduction gear 31 1 acts to step down the rotational speed of the output shaft 21 1. A sun gear 312 is mounted concentrically with the primary reduction gear 311 and rotates in unison with the primary reduction gear 311. Refening next to Figure 22, a motor plate 313 is fixedly mounted to the body 213 of the motor 210 at its output end. The primary reductio gear 31 1 and sun gear 3 12 (omitted from Figure 22) are mounted on a primary shaft 314 that is supported by a rear wall of the motor plate 313. The primary reduction gear 31 1 and motor output shaft 21 1 are housed within a recess 315 formed in the face of the motor plate 313. The wall extending about the opening of the recess 315 defines a stationar ring gear 316 that is concentric with the primary shaft 314. The primary reduction gear 31 1 and sun gear 312 are depicted in Figure 21 without the motor plate 313 for clarity purposes. Next referring to Figure 23., the sun gear 312 lies in the same plane as the stationary ring gear 316 and a set of three planet gears 317 are located in the annular cavity defined between the sun gear 312 and stationary ring gear 316. The planet gears 3.17 each engage both the sun gear 312 and the stationary ring gear 316. The primar reduction gear 311 , sun gear 312, stationary ring gear 316 and planet gears 317 together define a planetary primary gear assembly 321 of the li fting arrangement 310.

[0091] Next referrmg to Figure 24, the three planet gears 317 are each mounted on shafts 318 pressed into the rear face of a lift cam 31 , The lift cam 31 is depicted in place, co vering the planet gears 317, in Figure 25. The lift cam 319 is mounted on the primary shaft 314 which extends through an aperture 320 in the lift cam 31 , as best shown in Figure 24. A cam follower bearing 325 engages the upper surface of the lift cam 319 and moves up and down with the profile of the lift cam 319 as it rotates. Rotation of the lift cam 31.9 is generated by rotation of th motor output shaft 21 1 _} which in turn rotates the primary reduction gear 3 1 and sun gear 312, which in turn, moves the planet gears 337 in an orbiting motion about the sun gear 3 12. Orbiting motion of the planet gears 317 causes the lift cam 319 to rotate about the primar y shaft 314.

[0092] Referring next to Figure 26, the cam follower bearing 325 is mounted to the rear face of a lift member 326 of the lifting arrangement 3 10, by way of a fastener 327 extending through the cam follower bearing 325. The lift member 326 comprises a lift member body 328 with generall vertically extending and parallel primary guide rails 329 formed on the upper and lower portions of the opposing side edges of the lift member body 328. The lift member 326 further comprises a pair of opposing upper and lower flanges 330 projecting laterally from the upper and lower edges of the lift member body 328. The upper and lower flanges 330 define downwardly and upwardly facing, longitudinally extending, secondary guide rails 331 respectively. The primary and secondary guide rails 329, 33 1 are mutually substantially perpendicular.

[0093] The Sift member 326 is depicted in position on the face of the motor p late 313 in Figure 27. Primary guide bearings 332 are mounted on rite face of the motor plate 313 and engage the generally vertically extending primaiy guide rails 329 formed on the lift member body 328, The primary guide bearings 332 act to restrict motion of the lift member 326 to a generally vertical up and down motion aligned with the orientation of the primaiy guide rails 329, and substantiall perpendicular to the longitudinal orientation of the secondary guide rails 3 1. Accordingly, movement of the cam follower bearing 325 as it follows the profile of the rotating lift cam 319 is also restricted to a generally vertical up and down motion, resulting in reciprocating cyclic up and down motion of the lift member 326, which motion is transferred to the second rack 170 by way of the conveying arrangement 350 which, together with the adjusting mechanism 230. will now be described with reference to Figures 28 to 30 and Figure 20,

[0094] Firstly referring to Figure 28, the conveyi g arrangement 350 includes a secondary shaft 351 that is pressed into an aperture 333 formed in the face of a cylindrical boss 334 projecting front the face of the lift cam 319, The secondary shaft 351 is offset from the primary shaft 3 14 about which the lift cam 31.9 rotates. Accordingly, as the lift cam 319 rotates, the secondary shaft 351 orbits about the primary shaft 314. Stili referring to Figure 28, a roller bearin 231, forming part of the adjustment mechanism 230, is mounted about the boss 334 projecting from the front face of the lifting cam 319. Next referring to Figure 29, a cycloid ring gear 352, which forms part of both the conveying mechanism 350 and the adjustmen mechanism 230, is mounted on tlie roller bearing 231. The roller bearing 231 allows free relative rotation of t he boss 334 within the cycloid ring gear 352. The cycloid ring gear 352 is prevented from rotating with tlie boss 334 and lift cam 319 by way of a projection 232 extending from the radially outer surface of the cycloid ring gear 352 extending into the recess 233 of a guide 234 which will be described in further detail below.

[0095] Next referring to Figure 30, the conveying mechanism 350 further comprises a cycloid planet gear 353 mounted on the secondary shaft 351, which together with the cycloid ring gear 352 forms a cycloid gear assembly. The cycloid planet gear 353 engages tlie cycloid ring gear 352. Orbital motion of the secondary shaft 351 about the primary shaft 314 results in rotation of the cycloid planet gear 353 in mesh with the cycloid ring gear 352 such that the cycloid planet gear 353 rotates as it is driven along the cycloid ring gear 352. A driving pin 354 is mounted on the cycloid planet gear 353, offset from the secondary shaft 351 . A bearing 355 is mounted on the driving pin 354. Preferably the effective diameter of tlie cycloid planet gear 353 is half of the effective diameter of the cycloid .ring gear 352, This results in the path of travel of the drive pin 354 being linear.

[0096] Referring back to Figure 20, depicting the complete drive mechanism 200, the conveying arrangement 350 is completed b a conveying member 356 that, together with the driving pin 354, forms a Scotch yoke mechanism that provides linear longi tudinal displacement of the conveying member 356. Specifically, the conveying member 356 comprises a conveying member body 357 with secondary guide bearings 358 mounted toward opposing edges of the upper and lower ends of the conveying member bod 357. The secondary' guide bearings 358 engage the secondary guide rails 331 of the flanges 330 of the lift member 326, thereby limiti ng motion of the conveying member 356 relati ve to the lift member 326 to movement in the longitudinal direction. A general vertically extending slotted yoke 359 is formed on the conveying member body 357 with the drive pi 354 and bearing 355 bearing within the slot defined by the slotted yoke 359. The longitudinal component of cyclic motion of the dri ve pin 354 is converted to longitudinal motion of the conveying member 56, which is transferred to the second rack 150 by way of the drive arm 360 t hat extends from the c onveying member body 357.

[0097] Accordingly, the rotational output of the motor 210 is converted to generally vertical motion of the lifting member 326 by the lifting arrangement 310, which in turn is transmitted to the second rack 170 by virtue of the conveying member 356 being vertical ly fixed in relation to the lifting member 26 by engagement of the secondary guide bearings 3 8 on the secondary guide rails 331. Rotational output of the motor 210 is further converted to longitudinal motion of the conveying member 356, via the lifting arrangement 310 and conveying arrangement 350, which in turn is directly transferred to the second rack 170 b way of the drive arm 360.

[0098] The stroke of the convey ing phase of motion of the second rack 170 is defined by the longitudinal extent of motion of the drive pin 354. This stroke can be adjusted by the adjusting mechanism 230, by pivoting the cycloid ring gear 352 by way of the projection 232 extending from the cycloid ring gear 352, The pivotal displacement of the cycloid ring gear 352 is achieved by way of an adjusting knob 235 located on the front of the control enclosure 1 13 (as depicted in Figure 1). The adjusting knob 235 is mounted on the end a control shaft 236 having an adjustment gear 237 mounted on its end. The adjustment gear engages an adjustment rack 238 to which is mounted the guide 234 having the recess 233. Rotating the control knob 235 in an anti-clockwise direction results i the adjustment rack 238 being driven upwardly, which in turn pivots the cycloid ring gear 352 in an anti-clockwise direction toward the position depicted in Figures 30 and 31. Rotating the control knob 235 in a clockwise direction drives the adjustment rack 238 downwardly, which results in pivoting of the cycloid ring gear 352 in a clockwise direction toward the position shown in Figure 32.

[0099] Pivoting the cycloid ring gear 352 has the effect of rotating the path of the drive pin 354. With the control knob 235 turn to its fully anti-clockwise position, corresponding to the adjustment rack 238 in its highest position, as depicted in Figure 31, the path of motion of the drive pin 354 is as marked "A" in Figure 31. This provides a maximum longitudinal stroke marked "X" which, in a preferred embodiment, is approximately 24mm , This stroke equates to the stroke of the conveying phase of the second rack 170 and results in the maximum speed of the conveying mechanism 130.

[00100] When the control knob 235 is turned to its maximum clockwise position, corresponding to the lowest position of the adjustment rack 238, as depicted in Figure 32, the path of motion of the drive pin 254 is rotated to a near vertical path as marked "B" in Figure 32, providing a minhnu longitudinal stroke marked "Y" which, in a preferred embodiment, is approximately 3mm. This defines tlie minimum stroke of th conveying phase of the second rack 170, providing the minimum speed of the conveying mechanism 130. As will be appreciated, adjusting the speed of tlie conveying mechanism 130 via the adjustment mechanism 230 has no effect on the vertical stroke of the lifting member 326 and thus the extent of lifting and lowering of the second rack 170 in the lifting and lowering phases of motion.

[00101] The motion output b the drive mechanism 200 when in the maximum and minimum stroke positions is reflected in Figures 33 and 34 respectively. It can be seen that, whilst the longitudinal stroke varies significantly between the maximum and minimum stroke positions, the vertical stroke is not affected. The speed of conveying of bread through the toasting cavity 1 15 can thus be readily controlled without affecting the vertical motion of the second rack elements 1.75 required to lift bread from the first rack elements 155 and without adjusting the speed of the motor 210. It may also be noted from Figures 33 and 34 that the longitudinal displacements of the conveying and return phases are slightly inclined from the horizontal, with the up and down motion of the lifting and lowering phases being offset from the vertical by an equivalent angle, providing a substantially rectilinear motion. The motion paths are inclined as a result of the conveying mechanism 130 being slightly inclined, lower toward the front. This is purely for aesthetic purposes.

[00102] The toaster is provided with a control system that controls operation of the upper and lower heating elements ί 18, 119 and the drive mechanism 200 based on a sensor, mounted in the housing body 110 adjacent the toasting c avity inlet 1 16., that detects the presence of bread passing through the toasting cavity inlet 1 16 into the toasting cavity 1 15. If the upper and lower heating elements i 18, i. 19 are not heated at the time of first sensing a piece of bread fed into the toasting cavity inlet 116, the upper and lower heating elements 1 18, 1 19 are energized and operation of the motor 210 of the drive mechanism 200 is delayed until the heating elements 1 18, 1.19 and toasting cavity 1 15 reach a desired steady state heating state. This is to ensure consistent toasting of the first piece of bread toasted and subsequent pieces of bread following the first piece. Both the drive moto 210 and heating elements 1 18, 119 are also shut down to save energy a predetermined time after the last piece of bread is sensed entering the toasting cavity 1 15 by the sensor.

[00 i 03] Whilst the toaster has been described in relation to a unit having a si gle conveying mechanism 130 and associated drive mechanism 200, it is envisaged that the toaster may be formed as a double unit, having two side by side conveying mechanisms 30, each having its own associated drive mechanism 200. One side of the toaster can then be adjusted to provide a fast conveying speed through the toasting cavity, suitable for toasting light breads and, for example, fruit loafs, and the other side of the toaster may be adjusted to operate at a slower conveying speed, more suitable for toasting darker breads.

[00104] A modified form of the toaster described above, constituting a toaster according to a second embodiment, is depicted in Fi ure 35. The toaster of the second embodiment is substantially identical to the toaster of the first embodiment, with the addition of a reflector 124 mounted to the underside of the lower heating element 119 in the toasting cavit 115. The reflector 124 serves to reflect radiant heat from the lower heating element 1 19 upwardly toward the conveyor mechanism 1.30 and away from the toast collection cavity 121. The toaster of the second embodiment further has a guar d 125 mounted in the button of the toasting cavity 1 15, below the crumb tray 1 14, The guard 125 serves to protect the fingers of a user inserted into the collection cavity 121 to retrieve toast from touching the crumb tray 1 14.

[00105] An alternati ve form of drive mechanism 700 is depicted in a fully assembled form in Figure 36 and in various states of disassembly in Figures 37 to 42. The dri ve mechanism 700 is similar to the drive mechanism 200 described above. In particular, the drive mechanism 700 shares the same motor 210 and substantially identical adjustment mechanism 230 to that described above in relation to the drive mechanism 200. The gear mechanism 800 of the drive mechanism 700 also shares a substantially identical conveying arrangement 350 to tha described above in relation to the drive mechanism 200, but has an alternate form of lifting arrangement 810 configured to cyclically lift and lower the second rack 170, whilst providing an identical path of motion of the second rack 170 to that provided by the drive mechanism 200.

[00106] Referring specifically to Figure 37 to 40, the primary reduction gear 31 1 , sun gear 312, stationary ring gear 316 and planet gears 317 that define the planetary primary gear assembly 321 of the lifting arrangement 310 of the drive mechanism 200 described above are replaced by a primary gear assembly 821 in the form of a worm gear assembly. The primary gear assembly 821 includes a worm gear 81 1 that is dri ven by the motor output shaft 21 1 , rotating about an axis perpendicular to that of the motor output shaft 211. The worm gear 811 has a set of driven teeth 83 la driven by the motor output shaft 21 and a set of bevel driving teeth 81 lb. The primary gear assembly 821. further comprises a bevel gear 817, as best depicted in Figures 38, 39 and 42. The bevel gear 817 is driven by the driving teeth 81 lb of the worm gear 81 1. The primar gear assembly 821 acts to step down the rotational output of the motor output shaft 211. The bevel gear 817 is fixed to the rear face of a lift cam 319 that is

substantially identical to that of the lift cam 319 of the drive mechanism 200 described above and operates in the same manner. Replacement of the planetary primary gear assembly 321 of the drive mechanism 200 with the worm primary gear assembly 821 of the drive mechanism 700 simplifies tooling and reduces the level of gear noise in the dri ve mechanism 700. The remaining components of the dri ve mechan ism 700 are substantially identical to those of the dri ve mechanism 200.

[00107] A person skilled in the art will appreciate other possible modifications and variations to the toasters described above.