US20060163272A1 - Pusher apparatus for merchandise - Google Patents

Abstract

A pusher apparatus comprises a track, a pusher mounted on the track for movement along the track; a spring mounted on the pusher for urging the pusher along the track; an axle rotatably mounted on the pusher; and at least one wheel fixed to the axle for positively engaging the track. In one aspect of the invention, two of the said wheels are fixed to the axle to avoid canting of the pusher as it moves along the track. In another aspect of the invention, the spring is a coil spring contained within the pusher unit for driving rotation of the axle. Preferably, a rotary damper regulates the operation of the coil spring.

Description

TECHNICAL FIELD
• The invention relates to the field of pusher apparatus, i.e. apparatus for pushing a stack of items along a track. The main application for pusher apparatus is in merchandising of items for sale, whereby the front item of the stack of merchandise is always pushed to the front of the shelf. Pusher apparatus according to the invention may also operate vertically or at other angles and words such as “front”, “forwards” and “backwards” in this specification are not intended to limit its scope to horizontal operation. Pusher apparatus may clearly also be used in other situations where items are to be dispensed to a user, not necessarily for sale.
BACKGROUND
• It is known to use a pusher apparatus for automatically pushing items of merchandise to the front of a shelf, where they are more readily visible and accessible to a potential purchaser. This may particularly promote one type of merchandise, which is stacked on a pusher apparatus and therefore prominent at the front of the shelf, over adjacent merchandise that remains at the back of the shelf.
• A known pusher apparatus comprises a pusher unit that slides on a track. The pusher unit may be guided along the track by rails. The pusher unit is retracted against the force of a spring so that a stack of merchandise can be placed along the track. When the pusher unit is released, it urges the stack forwards until the front item of merchandise comes to rest against a lip at the front of the track. As each item of merchandise is removed, the remaining stack is urged forwards until the next item rests at the front of the track. Known springs in such pusher apparatus either have a concertina shape with one end attached to the back of the track and the other end attached to the pusher unit to push the pusher unit forwards; or have a coiled configuration with one end attached to the front of the track and the other end attached to the pusher unit to pull the pusher unit forwards.
• The known pusher apparatus suffers various problems. One is that of “racking”. If the merchandise being pushed is not centred on the pusher plate, there is a tendency for the pusher unit to cant to one side as it moves forwards. That can cause the pusher unit to wedge against the rails of the track, preventing further forward movement. The wider the pusher plate is, the greater is the potential turning moment of an off-centre load. This provides a practical limit to the width of the pusher plate and the size and weight of the merchandise that can be stacked on the apparatus.
• In the prior art, the speed of the pusher has also been a problem. The spring must be strong enough to push a full stack of merchandise against the force of friction between the stack and the track. When the same spring is acting on only a few items in the stack, it can accelerate them violently and push them too rapidly along the track There is a risk of injury to the fingers of a person who is loading the apparatus. There is also a risk that the rapidly moving items will be ejected from the front of the stack, causing them to fall and be damaged. To avoid the latter risk, the height of the retaining lip at the front of the track must be increased, which makes the items less visible and less accessible and requires a greater space above the shelf so that items can be lifted over the lip.
• Known pushers have been found not to work well in cold environments such as chiller or freezer cabinets. There is a problem with the build up of frost along the track, which impedes the sliding movement of the pusher unit. There is also a problem of ice adhering the pusher unit to the track.
SUMMARY OF THE INVENTION
• The invention provides pusher apparatus comprising: a track; a pusher mounted on the track for movement along the track; a spring mounted on the pusher for urging the pusher along the track; an axle rotatably mounted on the pusher; and at least one wheel fixed to the axle for positively engaging the track.
• Preferably, the track includes at least one line of slots or teeth along the track; and wherein each wheel is a cog bearing teeth for positively engaging the slots or teeth of the track.
• In a highly preferred embodiment, at least two wheels are fixed to the axle for simultaneous rotation. Because the two wheels positively engage the track, the two ends of the axle can only move simultaneously and the two sides of the pusher unit must advance in step along the track. Therefore the pusher unit does not cant to either side and the problem of racking is solved. To prevent relative rotational movement of the two wheels, the material of the axle must be sufficiently stiff under torsional stresses. For ordinary small and lightweight applications, plastics materials should suffice but for pushing heavy items with a wide pusher plate a stronger material such as steel may be required.
• The spring may be a coil spring. In a preferred embodiment, the spring is coiled about the axle, one end of the spring being secured to the axle and the other end of the spring being attached to the pusher, whereby the coiling or uncoiling of the spring drives rotation of the axle. In this embodiment, the spring can be contained entirely within the housing of the pusher unit, where it is hidden from view and also protected from dirt that may accumulate on the track. The pusher may be started from any point on the track then retracted and, as the spring unwinds, it will naturally return to its starting point.
• In an alternative preferred embodiment, a first end of the coil spring is attached to a front end of the track and the second end of the spring is attached to the pusher, whereby the coiling of the spring draws the pusher along the track. In this embodiment the pusher is started from a fixed point at the end of the track and its forward movement ends when it returns to the fixed point. That is not necessarily when the spring is in a fully relaxed condition, which has the advantage that the spring may still provide a useful driving force even near the end of the track. The same embodiment may further comprise a second axle rotatably mounted on the pusher, wherein the spring is coiled about the second axle and the second end of the spring is attached to the second axle. By using separate axles for mounting the spring and the cogs, each axle can be designed optimally for its own function and it is not necessary to ensure that the number of turns on the spring matches the number of turns of the cogs.
• As an alternative, the coil spring need not be mounted on an axle, provided that it is constrained to coil appropriately within a suitable housing.
• The spring does not have to be located centrally on the track and if there is an independent spring axle, the independent axle need not be parallel to the gear axle. For example, the spring axle can have a vertical axis and the spring can run along a side wall of a channel in which the track is located.
• The gear axle does not have to be perpendicular to the length of the track. With an oblique gear axle, each individual slot should extend parallel to the gear axle to accommodate a component of motion of the gear tooth parallel to the axle as the pusher slides along the track.
• It is strongly preferred that the pusher apparatus comprises a rotary damper mounted on the pusher for regulating the rate of coiling or uncoiling of the spring. The damper allows the use of a spring strong enough to move the largest loads expected when the stack is full but prevents the pusher from moving too fast when only a light load is present. Therefore the problems of potential injury and of spilt merchandise are avoided. The damping effect of the rotary damper may be adjustable so that a single design of pusher apparatus can accommodate merchandise of widely differing weights. Other kinds of damper such as a linear damper arranged along the track could also be used.
• The pusher apparatus preferably includes a latch for retaining the pusher at a desired position along the track, so that the operator can have both hands free when loading a stack of merchandise. The latch may be releasable by trigger means located at the front end of the track. Alternatively, the latch may be releasable by applying rearward pressure to the pusher.
THE DRAWINGS
• FIG. 1 shows a pusher apparatus according to a first embodiment of the invention in vertical cross section on line I-I ofFIG. 2.
• FIG. 2 shows the pusher apparatus ofFIG. 1 in plan view, sectioned along line II-II ofFIG. 1.
• FIGS. 3 and 4 show the pusher apparatus ofFIG. 1 in a perspective view and illustrate the operation of the latch mechanism.
• FIG. 5 shows in perspective view a pusher apparatus according to a second embodiment of the invention.
• FIGS. 6, 7 and8 show the pusher apparatus ofFIG. 5 in plan view, side view and end view respectively, each view having part of the housing cut away to reveal the interior.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• The pusher apparatus shown in FIGS.1 to4 comprises anelongate track2, which in use rests on or is integral with a shelf (not shown) for displaying merchandise. Apusher unit4 is mounted on thetrack2 so as to be capable of sliding along thetrack2.Merchandise6 for display is stacked along thetrack2 and is engaged by apusher plate8 of thepusher unit4.
• Acoil spring10 is coiled about aspring axle12 that is rotatably mounted in thepusher unit4, one end of the spring being attached to a ring (not shown) freely rotatable on thespring axle12. The other end of the spring is attached at14 to thetrack2, near to the front end of thetrack2. As thepusher unit4 is drawn back along the track to the position shown inFIG. 1, thespring10 uncoils and lies flat along thetrack2. The natural tendency of thespring10 to coil up again draws thepusher unit4 forwards along thetrack2, pushing the items ofmerchandise6 on the track ahead of it, until the front item engages alip16 at the front end of thetrack2. When the front item of merchandise is removed from the shelf, thespring10 is free to re-coil further and thepusher plate8 pushes the remaining stack ofmerchandise6 forwards until the next item rests against thelip16 at the front of thetrack2.
• Agear axle20 is also mounted in thepusher unit4 so as to be freely rotatable. Fixed to thegear axle20 are twocogs22, which therefore rotate simultaneously when thegear axle20 rotates. When thepusher unit4 rests on thetrack2, the teeth of eachcog22 engage a line ofslots24 in the track in a rack-and-pinion arrangement As shown, the ends of the cog teeth are rounded to engage withrectangular slots24. However any suitable shape of cog teeth may be used with complementary teeth or slots in the track, as is well known. Because the twocogs22 are connected together by therigid gear axle20, the two sides of thepusher unit4 must move forwards simultaneously and thepusher unit4 is unable to cant to one side, which caused the racking problem in the prior art. Because of this resistance to racking, thepusher plate8 in the apparatus ofFIGS. 1 and 2 can be considerably enlarged and the apparatus can be used for bulky and heavy items ofmerchandise6.
• Rotation of thegear axle20 is controlled by arotary damper18 mounted in thepusher unit4. Therotary damper18 is preferably a one-way damper so that thepusher unit4 may be easily retracted for filling the shelf but the forward movement of thepusher unit4 under the influence of thespring10 is controlled by thedamper18. The damping level of therotary damper18 should be selected so that when the shelf is full and thespring10 is fully stretched, themerchandise6 does not move forwards at too high a speed, which might cause it to tip over thelip16 at the front of thetrack2. On the other hand, thespring10 must be able to overcome the resistance of thedamper18 and the friction of the moving parts against thetrack2 in order to move the final item ofmerchandise6 when thespring10 is almost fully coiled and at its weakest. Therotary damper18 acts by a viscous fluid which resists the movement of vanes or valves (not shown) driven by rotation of thegear axle20. If the pusher apparatus is to be used in a cold environment such as a freezer, the fluid becomes more viscous and the damping effect is increased.
• The pusher apparatus is also provided with a latch, which holds thepusher unit4 at the retracted position (shown inFIG. 3) along thetrack2, against the bias of thespring10, to allow for ease of filling the shelf withmerchandise6. Thelatch26 is connected by arod28 running beneath thetrack2 to atrigger30, by which thelatch26 may be released (as shown inFIG. 4) to allow thepusher unit4 to move along thetrack2.
• An alternative latch (not illustrated) may be a double-action latch fixed to the rear end of thetrack2. When thepusher unit4 is first pushed back against the latch, it latches and holds the pusher unit stationary against the bias from thespring10. Thepusher unit4 may be pushed back a second time to release the latch. A still further alternative (not illustrated) may be to mount the latch entirely on thepusher unit4. However, that is then more difficult to access when thepusher unit4 is retracted and the shelf is full of merchandise.
• Another embodiment of the invention, which is better suited to small and lightweight merchandise such as cigarette packets, is illustrated in FIGS.5 to8. Atrack52 of π-shaped cross section may be mounted in a channel or between walls on a shelf (not shown) where merchandise is to be displayed. Apusher unit54 is mounted so as to be slidable along thetrack52. Thepusher unit54 haslugs56 for engagingflanges58 on thetrack52 to prevent thepusher unit54 from being lifted off thetrack52.
• Mounted for rotation in thepusher unit54 is anaxle60. One end of theaxle60 engages arotary damper62 and the other end engages abearing64. Fixed to theaxle60 is acog66. When thepusher unit54 is mounted on thetrack52, the teeth of thecog66 engage a line ofslots68 along thetrack52 in a rack-and-pinion arrangement. As shown, the ends of the cog teeth are rounded to engage withrectangular slots68. However any suitable shape of cog teeth may be used with complementary teeth or slots in the track, as is well known.
• Acoil spring70 is coiled around theaxle60. One end of the coil spring is fixed to theaxle60 and the other end to a mounting72 on the housing of thepusher unit54. Thereby, when thespring70 coils or uncoils, theaxle60 rotates within thepusher unit52 in the manner of a clockwork mechanism. The rate of rotation of theaxle60 is controlled by therotary damper62.
• In use, thepusher unit54 is mounted at the front end (not shown) of thetrack52 with thecoil spring70 in its relaxed state. Thepusher unit54 is then pushed back along thetrack52 causing thecog66 to rotate theaxle60 and coil thespring70 more tightly. A stack of merchandise items may then be placed on thetrack52 in front of thepusher unit54 and behind a front product stop (not shown). The product stop may be integral with, attached to or adjacent to thetrack52. When thepusher unit54 is released, thespring70 attempts to uncoil and it urges thepusher unit54 forwards along thetrack52 until the front item of merchandise rests against the product stop at the front of thetrack52. As each item of merchandise is removed, thespring70 uncoils further and thepusher unit54 moves the stack of merchandise forwards so that an item is always presented at the front of the shelf. When the last item is removed and thepusher unit54 reaches the front of thetrack52 once more, thecoil spring70 is then back in its relaxed state and the forward movement ceases.
• This embodiment of the invention is capable of working with tracks that bend upwards or downwards or (within certain limits of curvature) sideways, which may allow the design of attractive and unusual merchandising displays.
• One or more hybrids between the two illustrated embodiments of the invention are also possible. For example, thespring70 contained wholly within thepusher unit54 of the second embodiment may be combined with the twin cogs22 andtrack2 of the first embodiment to resist racking. In that case, thecogs22 and thespring70 will share a common axle.

Claims (12)

1. Pusher apparatus comprising:

a track;

a pusher mounted on the track for movement along the track;

a spring mounted on the pusher for urging the pusher along the track;

an axle rotatably mounted on the pusher; and

at least two wheels fixed to the axle for simultaneous rotation, wherein each wheel positively engages the track.

2. Pusher apparatus according toclaim 1, wherein the track includes at least one line of slots along the track; and wherein each wheel is a cog bearing teeth that positively engage the slots of the track.

3. Pusher apparatus according toclaim 1, wherein the track includes at least one line of teeth along the track; and wherein each wheel is a cog bearing teeth that positively engage the teeth of the track.

4. Pusher apparatus according toclaim 1, wherein the spring is a coil spring.

5. (canceled)

6. Pusher apparatus according toclaim 4, wherein a first end of the spring is attached to a front end of the track and a second end of the spring is attached to the pusher, whereby coiling of the spring draws the pusher along the track.

7. Pusher apparatus according toclaim 6, further comprising a second axle mounted on the pusher, wherein the second end of the spring is coiled about the second axle

8. Pusher apparatus according toclaim 4, further comprising a rotary damper mounted on the pusher for regulating the rate of coiling or uncoiling of the spring.

9. Pusher apparatus according toclaim 8, wherein the rotary damper includes means for adjusting a damping effect of the rotary damper

10. Pusher apparatus according toclaim 1, further comprising a latch for retaining the pusher at a desired position along the track

11. Pusher apparatus according toclaim 10, further comprising trigger means located at the front end of the track, wherein the latch is mounted on the track and is operable by the trigger means to release the pusher from the desired position.

12. Pusher apparatus according toclaim 10, wherein the latch is mounted on the track and is operable to release the pusher from the desired position by applying rearward pressure to the pusher.

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