Abstract:
A dispenser for dispensing a fluid product includes an assembly of a collapsible reservoir and a pump, a housing for removably accommodating the assembly, and means for actuating the pump. The housing includes a tensioning element, or tensioning means, which is configured to counteract, or negate, compression of the collapsible reservoir as fluid is removed from the collapsible reservoir. By counteracting compression of the collapsible reservoir, the tensioning element, or tensioning means, may prevent trapping of fluid product in the collapsible reservoir.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority pursuant to the Paris Convention to European Patent Application 06075257.3, filed Feb. 7, 2006, the disclosure of which is hereby incorporated herein, in its entirety, by this reference. This application also claims the benefit of U.S. Provisional Application No. 60/771,483, filed Feb. 9, 2006, the disclosure of which is hereby incorporated herein, in its entirety, by this reference. 
     
    
     FIELD OF INVENTION  
       [0002]     The present invention relates to a dispenser for dispensing a fluid product and, more specifically, to a dispenser that includes a reservoir and an associated tensioning means for counteracting contraction of the reservoir when the reservoir is at least partially filled.  
       BACKGROUND OF RELATED ART  
       [0003]     Fluid product dispensers with collapsible reservoirs and pumps for drawing fluid from the collapsible reservoirs and dispensing the fluid are well known. An example of such a fluid product dispenser is described inter alia in U.S. Pat. No. 5,445,288. Such dispensers are, for example, employed in washrooms, toilets, kitchens, hospitals, surgeries, hair/beauty salons, workshops and factories. In many cases, such dispensers are mounted to a wall, often in the vicinity of a basin, bath, shower or toilet bowl; alternatively, such dispensers may be free-standing, and may be placed on a shelf, worktop or wash hand basin, or a trolley. In use, the actuating means are typically operated by hand, arm or elbow so as to dispense a quantity of fluid product. In many applications, a fluid product will be dispensed into the operator&#39;s hand or onto a carrier, such as a cloth, after which the fluid product is rubbed onto skin, or is applied from said carrier onto a surface to be treated, such as a metal or ceramic surface to be cleaned, for example.  
         [0004]     Because the reservoir in such a dispenser is collapsible, and because the pump withdraws liquid product from the reservoir without an air return (or substantial flow of other gas) back into the reservoir, the reservoir will steadily contract in upon itself as more and more of the liquid product is withdrawn by the pump. Such contraction tends to push liquid product out of the reservoir, helping to ensure that the reservoir is substantially emptied before it has to be replenished. However, despite this contraction effect, a certain amount of liquid product nevertheless tends to get trapped in the reservoir, particularly along folds, seams and/or gussets that may be present in the reservoir, or in internal corners; such product is essentially wasted, since it is discarded with the old reservoir once a new reservoir is loaded into the housing. The quantity of liquid product wasted in this manner depends inter alia on the viscosity of the liquid product.  
         [0005]     This wastage problem can become particularly significant in the case of relatively viscous liquid products such as thick soap or detergent solutions, especially those containing a suspended granulate solid; liquid products containing such a granulate solid often contain chemicals that deliberately increase their viscosity, so as to prevent the particles of the granulate solid from settling or floating out of homogeneous suspension. Many such liquid products can have viscosities of the order of 10 4  to 10 5  times as high as that of a watery soap solution typically used in conjunction with a foam or spray pump, for example. In tests, it has been observed that, even when the employed reservoir is a thin-walled plastic foil bag (see, e.g., U.S. Pat. No. 5,732,853), as much as 6 to 8% of the initial load of liquid product can get trapped in the reservoir when high-viscosity liquid products are used; this percentage is significantly higher when the employed reservoir is a relatively stiff-walled collapsible container, as in the abovementioned U.S. Pat. No. 5,445,288, for example.  
         [0006]     The trapping of liquid product within collapsible reservoirs is somewhat undesirable for a number of reasons. For example, the liquid products concerned often contain relatively expensive chemicals, e.g., to keep them aseptic, prevent clotting, maintain the correct buoyancy level for suspended granulates, effectively dissolve various types of dirt, etc. As a result of the use of these chemicals, the products can cost on the order of about $100 per gallon (or about          20 per liter). Wasted liquid product can therefore translate to relatively significant sums of wasted money.  
         [0007]     As another example of the undesirability of wasted liquid product within a collapsible reservoir, the presence of substantial quantities of trapped liquid product in a depleted reservoir will generally mean that that reservoir will have to be treated as chemical refuse rather than as simple plastic residue. This obviously puts a greater potential strain on the environment. As a result, more elaborate disposal procedures are necessary, with an attendant increase in costs.  
         [0008]     It should also be noted that many jurisdictions are currently considering stringent legislation to force manufacturers to package their wares in an environmentally responsible manner. However, as a possible alternative to such legislation, some governments are willing to first evaluate the results that can be achieved by self-imposed waste-reduction covenants in various branches of industry. Manufacturers would generally prefer to have to work with such self-imposed covenants than with more explicit legislation, and are thus eagerly seeking measures to reduce waste.  
       SUMMARY OF THE INVENTION  
       [0009]     For purposes of clarity and consistency, the following terms as used throughout this text and the appended claims:  
         [0010]     The term “fluid” may be interpreted to include a liquid, a suspension of a granulate solid in a liquid, a gel, and a foam, for example.  
         [0011]     The term “product” may be interpreted to include soap (including shower gel), detergent, and exfoliating scrub, as well as mixtures of these substances, for example.  
         [0012]     The “liquid product” may be dispensed directly through the pump, or may first be mixed with another substance, such as air or another gas, another liquid, or a granulate solid, for example.  
         [0013]     The term “pump” refers to any type of pump suitable under the circumstances. The pump in question may employ a piston, bellows, and/or membrane, for example.  
         [0014]     A dispenser according to the present invention may include a housing for removably accommodating an assembly that includes a collapsible reservoir and a pump. The collapsible reservoir is configured to contain a liquid product. The pump is connected to the reservoir and is configured to dispense a fluid product using the liquid product as an input. When the assembly is accommodated in the housing, the pump may be located at the underside of the reservoir. The liquid product may be withdrawn by the pump from the reservoir without a substantial gas flow back into the reservoir. The dispenser may further include actuating means for actuating the pump so as to dispense fluid from the pump to the exterior of the assembly. In addition, a dispenser that incorporates teachings of the present invention may be configured to help reduce waste of liquid product, such as liquid product that may otherwise be trapped in a collapsible reservoir.  
         [0015]     The collapsible reservoir of a dispenser of the present invention may have a relatively flat form when empty and a relatively bulged form when at least partially filled, whereby bulging of the reservoir along a first direction occurs as a result of corresponding contraction of the reservoir along a complimentary second direction. To counteract, or negate, this contraction, the dispenser (e.g., the housing thereof) may include tensioning means for applying an external force to the reservoir which is tensile along the second direction.  
         [0016]     Since bulging of a collapsible reservoir may be caused by the act of (partially) filling an empty reservoir that is relatively flat to start off with, a constant attempt to negate this bulging may thus amount to a constant attempt to revert the reservoir to flatness and emptiness. Stated another way, the tensioning means in the housing according to the invention may actively squeeze liquid product out of the reservoir, rather than just passively relying on gravity to cause as much liquid product as possible to migrate toward the pump. By applying a tensile force along the second direction, the bulging of the reservoir is pulled inward in a substantially homogeneous manner, thus decreasing the risk that excessive crumpling of the reservoir will occur, and therefore reducing the attendant risk of liquid product getting trapped in the internal folds, corners, etc., arising from such crumpling.  
         [0017]     In an embodiment of a dispenser according to the invention, the tensioning means may include suspending means for suspending the reservoir by a first extremity so that it hangs under the force of gravity, the pump being attached to a second extremity of the reservoir located opposite the first extremity. Because the reservoir is hung up in the housing rather than, for example, sitting on a retaining shelf, the weight of the reservoir and its contents apply a tensioning force to the reservoir along the vertical direction (second direction), thus serving to counteract the (net) outward bulging of the reservoir in the horizontal direction (first direction).  
         [0018]     In some embodiments of a dispenser according to the invention, the suspending means may include a drum that can be rotated about a substantially horizontal axis. Such a drum may be rotationally/torsionally biased (e.g., using a spiral spring, elastic belt, etc.) in a first rotational sense, and the top of the reservoir may be hung on the drum in such a manner that the weight of the reservoir (including any liquid product therein) exerts a moment on the drum in a second rotational sense opposite to the first rotational sense. It has already been set forth above that, as the empty reservoir is filled, it starts to bulge outward along a first direction, which causes an attendant contraction of its length along a complimentary second direction; conversely, as the reservoir is emptied, the tensile force applied by the tensioning means according to the invention causes the reservoir to expand along the second direction in response to an attendant decrease of the bulge along the first direction. In a situation as set forth in the preceding paragraph, in which the top (first extremity) of the reservoir were simply hung from a fixed point, this lengthening would tend to cause the lowest point (second extremity) of the reservoir to move steadily downward as the reservoir was emptied; however, since the pump is attached to this lowest point, and since it is generally desired to keep the pump and its connection to the reservoir at a fixed level/posture, such steady downward motion may be undesirable. The biased drum set forth at the start of this paragraph addresses this issue in that, as the reservoir empties, its weight decreases, as a result of which: 
        the moment exerted by the reservoir in the second rotational sense reduces, so that;     the drum can relax in the first rotational sense, as a consequence of which;     the upper portion of the reservoir is “rolled onto” the drum, thus taking up the slack caused by the expansion of the reservoir along the second direction, and, thus;     the lower portion of the reservoir can remain at a steady level in the dispenser.        
 
         [0023]     In tests of such a dispenser according to the invention, the inventor used a thick soap solution comprising a suspended granulate solid; commercially available examples of such a solution/suspension include Deb SWARFEGA™, Stockhausen STOKO SOLOPOL™ and CWS ABRASIVA™. The viscosity of this (thixotropic) solution/suspension was measured to be on the order of 10 5  centipoise in static measurements, and of the order of 4×10 3  centipoise in dynamic measurements. The employed reservoir was a plastic foil bag having two major opposing flat surfaces, which were sealed together at the head and foot and were joined at the sides by foil sheet parts with a central longitudinal folding seam; in this manner, the reservoir could collapse flat in a concertina-like fashion. This reservoir was suspended from a drum arrangement as set forth in the preceding paragraph. It was observed in this instance that as little as 0.9 to 2% of the initial load of viscous liquid product got trapped in the reservoir, which represents an improvement of a factor of at least three (and, in many cases, a factor of eight or more) compared to the results obtained using a non-inventive dispenser (see “BACKGROUND OF RELATED ART” above).  
         [0024]     The pump may include a liquid inlet valve for admitting liquid product into the pump from the reservoir, the influx of liquid product through the valve occurring along a flow axis; and the housing comprises clamping means for clamping the pump in a given posture, whereby the pump is thus postured by the clamping means that the flow axis is substantially horizontal. When the pump is actuated so as to dispense fluid, the liquid inlet valve may shut tightly so as to minimize migration of liquid product from the pump back into the reservoir. In the case of a liquid product containing a suspended granulate solid, a build-up of granulates within the liquid inlet valve (e.g., between a ball bearing/flap member/top hat member and a corresponding valve seat, or in the throat of a duckbill valve) can prevent the valve from shutting properly, and this can result in the creation of a substantial dead volume upstream of the valve. However, by ensuring that the flow axis into the valve is substantially horizontal, such an accumulation of granulates in the valve may be minimized. It is believed that if a buoyancy imbalance arises and granulates start to precipitate out of suspension, they will either sink downward (parallel to the direction of gravity) or float upward (anti-parallel to the direction of gravity). In the event of a vertical flow axis through the valve, a sinking effect would tend to cause a forward accumulation of granulates at the entrance side of the valve, whereas a floating effect would tend to cause a similar backward accumulation at the exit side of the valve, either of which would eventually lead to incorrect operation (jamming) of the valve. However, by arranging the flow axis to be horizontal (or, at least, substantially horizontal), the component of gravity along the flow axis is zero (or, at least, substantially zero), thus, it is currently believed, avoiding the accumulation effects described above.  
         [0025]     As indicated in the opening paragraph, when the assembly of reservoir and pump is accommodated in the housing, the pump is located at the underside of the reservoir. For example, a throat may be provided at (or proximal to) the lowest point of the reservoir, and this throat may be connected to the liquid inlet valve of the pump (see previous paragraph) using a duct; see, e.g., the abovementioned U.S. Pat. No. 5,732,853. The inventor has observed that, in the case of viscous liquid products as alluded to above, the distance H between the liquid inlet valve of the pump and the point at which the pump is attached to the reservoir is preferably kept as short as possible; for example, in the previous sentence, said duct is ideally kept as short as possible (without sacrificing practicality). In this manner, pressure loss in the head H is kept to a minimum, so that the ability of the pump to suck liquid product out of the reservoir is optimized. This helps achieve a further reduction in the amount of liquid product trapped in the reservoir.  
         [0026]     The actuating means of a dispenser of the present invention may include at least one of: 
        an actuating organ movably connected to the housing and serving to cooperate with said pump, whereby the pump can be actuated by manually moving the actuating organ;     a detector, for detecting that a member onto which fluid is to be dispensed has been offered to a dispensing head of the pump; and     an electric actuator, for actuating the pump on the basis of a signal output from the detector.        
 
         [0030]     Other features and advantages of the present invention will become apparent to those of ordinary skill in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0031]     The invention will now be elucidated in more detail on the basis of the accompanying schematic drawings, which depict examples of various aspects and features of the present invention, and in which:  
         [0032]      FIG. 1  renders a perspective view of an example of a dispenser;  
         [0033]      FIG. 2  renders a longitudinal cross-sectional view of the subject of  FIG. 1 , taken along the line A-A′; and  
         [0034]      FIG. 3  renders a longitudinal cross-sectional view of a dispenser according to an embodiment of the current invention. 
     
    
       [0035]     In the drawings, corresponding elements are denoted by corresponding reference symbols.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0036]      FIG. 1  renders a schematic perspective view of part of a dispenser  10  for dispensing a fluid product.  FIG. 1  shows a housing  12 , which can be mounted to a wall of a washroom, for example. The housing  12  accommodates an assembly C that includes a collapsible reservoir  20 , for containing a liquid product, and an attached pump  22 ; these items are only visible in  FIG. 2 , and will be discussed later in more detail. Actuating means  14  are movably connected to the housing  12 , and can be actuated so as to operate said pump  22 . Also shown are an inspection window  16 , which allows the amount of liquid product in the reservoir  20  to be seen from outside. An aperture  18  allows insertion of a tool with the aid of which the housing  12  can be unlocked and opened, allowing access to the assembly C (including reservoir  20  and pump  22 ) located within. The housing  12  is made from any suitable rigid material, such as metal or a plastic, for example.  
         [0037]      FIG. 2  renders a cross-sectional view of the subject of  FIG. 1 , taken along the line A-A′. The reservoir  20  is now visible, and is here embodied as a flexible plastic container. The liquid product contained in the reservoir  20  may, for example, include soap, shower/bath gel, detergent, exfoliating scrub, or mixtures of (certain of) these products.  
         [0038]     A pump  22  is attached to the underside of the reservoir  20 , so as to be able to draw liquid product from within the reservoir  20 ; since the pump  20  does not replace such withdrawn liquid product by air (or another gas), the reservoir  22  collapses inward as more and more liquid product is withdrawn therefrom. The pump  22  may be any suitable type of pump for the application in question, such as a liquid pump, spray pump or foam pump, for example, and may operate on the basis of a movable piston, bellows and/or membrane, for example. In operation, the pump  22  may directly dispense the liquid contained within the reservoir  20 , or may first mix it with air to form a spray or foam, for example. The pump  22  dispenses a fluid product from the nozzle  24 . More information with regard to pumps suitable for use in this type of application can, for example, be gleaned from U.S. Pat. No. 5,271,530 and U.S. Patent Application Publication 2004/0149777, and from the website www.airspray.nl, the disclosures of each of which are incorporated herein, in their entireties, by this reference.  
         [0039]     As can be seen in  FIG. 2 , the actuating means  14  in this instance are hinged to the housing  12  via a hinge joint  26 . This, together with the gap  28  below the actuating means  14 , ensures that the actuating means  14  can be swung in and out of the housing  12 . An arm  30  connects the actuating means  14  to the pump  22  in such a manner that, when the actuating means  14  are swung into the housing  12  about hinge point  26 , arm  30  operates pump  22  so as to dispense a dose of fluid product through the nozzle  24 . Biasing means, such as spring  32 , ensure that the actuating means  14  are urged back into their swung-out position when released. In many applications, a user depresses the actuating means  14  using his hand palm, lower arm or elbow, for example, and collects the fluid product dispensed from the nozzle  24  in his hand or on a carrier (such as a cloth or tissue); in such applications, the nozzle  24  will generally face substantially downward.  
         [0040]     The pump  22  is removably mounted to a bracket  36  that protrudes from the back wall  34  of the housing  12 . This back wall  34  can be provided with screw-holes, magnets, or other means for mounting it to a wall or other surface. Also protruding from the back wall  34  is a lug  38 B, which grips a cooperating lug  38 A; however, using a tool inserted through aperture  18 , these two lugs  38 A,  38 B can be disengaged, allowing the housing  12  to be opened, e.g., so as to replace the reservoir  20  and/or pump  22  located inside (this may involve replacing either the entire assembly C as a whole, or replacing the reservoir  20  or pump  22  as parts).  
         [0041]     As is evident from  FIG. 2 , the bracket  36  not only supports the pump  22 , but also indirectly supports the reservoir  20  from beneath. The reservoir  20  is, therefore, free to sag downward and bulge sideways. Such free sagging/bulging is conducive to the formation of folds and corners in which liquid product can be trapped as the reservoir  20  collapses in upon itself.  
         [0042]      FIG. 3  renders a longitudinal cross-sectional view of a dispenser  10  according to an embodiment of the current invention. As in the example shown in  FIG. 1 , the dispenser  10  includes a housing  12  for removably accommodating an assembly C comprising a collapsible reservoir  20  and a pump  22  that is connected to the reservoir  20 . In addition, the dispenser  10  of  FIG. 3  includes tensioning means T, the operation of which will now be explained.  
         [0043]     The reservoir  20  in the current case is a plastic foil bag includes two major opposing surfaces  20   a  that are sealed together at a first extremity (head) E 1  and a second extremity (foot) E 2 , and are joined at the sides by an arrangement of foil sheet parts  20   b  with a central longitudinal folding seam  20   c . Due to this construction, the reservoir  20  may collapse (substantially) flat in a concertina-like manner, whereby the parts  20   a  and  20   b  fold toward one another, hinging inward about the folding seam  20   c . Consequently, the reservoir  20  has a relatively flat form when empty and a relatively bulged form when at least partially filled, whereby bulging of the reservoir along a first direction (the outward arrows F) occurs as a result of corresponding contraction of the reservoir along a complimentary second direction (the inward arrows G). In a particular example, the plastic foil of the parts  20   a  and  20   b  may, for example, include polyethene (PE), polyamide (PA), polyethene terephthalate (PET), polypropene (PP), ethene-vinyl alcohol polymer (EVOH), or combinations (e.g., sandwiches/laminates) of these materials.  
         [0044]     The housing  12  includes tensioning means T for applying an external force to the reservoir  20 , which force is tensile along the second direction G. By tensing/stretching the reservoir  20  along the direction G (which amounts to pulling extremities E 1  and E 2  away from one another, i.e., opposite to the indicated arrows G), the outward bulging of the reservoir in the direction of the arrows F is counteracted. As here depicted, the tensioning means T include suspending means  46  for suspending the reservoir  20  so that it hangs/dangles in the housing  12  under the force of gravity; this contrasts with the situation in  FIG. 2 , in which the reservoir  20  is supported from beneath. Such hanging suspension of the reservoir  20  under its own weight applies a basic tensile force to the reservoir along the second direction G.  
         [0045]     As here depicted, the suspending means  46  take the form of a lug in the housing  12 , which lug cooperates with (for example) a hook or a hole provided through the sealed extremities of the faces  20   a  of the bag  20 . However, as an alternative to such an arrangement, the skilled artisan could also easily conceive other suspending means  46  for suspending the reservoir  20 , e.g., using clamping jaws, Velcro, adhesive tape, etc. In general, suspending the reservoir  20  along a line (or a distribution of points) has been observed to give more satisfactory results than suspending the reservoir  20  at a single point (or relatively confined area).  
         [0046]     In a refinement of the tensioning means T, the suspending means  46  are provided on the cylindrical surface of a drum  40  that can be rotated about a substantially horizontal axis; in the drawing, the drum  40  is fitted on a substantially horizontal axle  42  provided at one end of an arm  44  that extends outward from the back wall  34  of the housing  12 . This drum  40  is rotationally/torsionally biased about the axle  42  (using biasing means that have not been depicted in the figure, but that may include a spiral spring or elastic belt, for example) such that the drum wants to roll in the direction of the arrow H (first rotational sense), which is opposite to the moment (in the second rotational sense) exerted on the drum  42  by the weight of the reservoir  20  (including the weight of any liquid product within the reservoir  20 ). This has two effects, namely: 
        it results in an additional tensioning/stretching force on the reservoir  20  along the second direction G;     it causes the upper portion of the reservoir  20  to be rolled onto the drum  40  as the reservoir  20  empties, thus taking up the slack that arises as a result of the relaxation of the reservoir along the second direction G, and, consequently, ensuring that the second/lower extremity E 2  of the reservoir  20  remains at a substantially constant horizontal level in the housing  12 .        
 
         [0049]     At the second/lower extremity E 2  of the reservoir  20  is a collar  21   a  providing flow access to the inside of the reservoir  20 . The pump  22  is attached to the reservoir  20  at this point (e.g., by clamping) so that an inlet duct  21   b  of the pump  22  fits into the collar  21   a  (see, e.g., the construction set forth for this purpose in the abovementioned U.S. Pat. No. 5,732,853, the entire disclosure of which is hereby incorporated herein, in its entirety, by this reference). Within the pump  22  is a non-return liquid inlet valve  23  for admitting liquid product into the pump  22  from the reservoir  20 , the influx of liquid product through the valve  23  occurring along a flow axis I. With the aid of clamping means  13  provided as part of the housing  12 , the pump  22  is held/postured in such a manner that the flow axis I is substantially horizontal.  
         [0050]     The inventor has observed that, in the case of relatively viscous liquid products (e.g., products with a viscosity in the range 10 3  to 10 5  centipoise: see above), the distance H between the liquid inlet valve  23  of the pump  22  and the point  21   a  at which the pump  22  is attached to the reservoir  20  is preferably kept as short as possible; in the current case, this implies that the inlet duct  21   b  should have a minimum (practicable) length. In this manner, pressure loss in the head H is kept to a minimum, so that the ability of the pump  22  to suck liquid product out of the reservoir  20  is optimized.  
         [0051]     It should be noted that the pump  22  shown in  FIG. 3  may also be tilted upward from horizontal. If one decides to use the pump  22  at such an above-horizontal angle, then one should generally ensure that: 
    the lower part of the reservoir  20  in the vicinity of the second extremity E 2  is not kinked, which might cause an undesirable restriction in the flow of liquid product out of the reservoir  20 ;     the head H referred to in the previous paragraph does not have to be made disadvantageously long in order to accommodate the upward tilt of the pump  22 .    
 
         [0054]     As here depicted, the actuating means  14  merely include a cap on the pump  22 , which cap can be operated by hand. However, more elaborate actuating means can also be employed as an alternative to this simple arrangement, as set forth above.  
         [0055]     A further embodiment of a dispenser  10  according to the present invention is identical to that described above with respect to  FIG. 3 , except as regards certain details of the tensioning means T. In this further embodiment, instead of rotationally biasing the drum  40 , it can instead be used as a rotating pulley or a static sliding guide, and a spring or hanging counterweight (neither of which is depicted) can be used to tension the extremity E 1  of the reservoir over this pulley/guide. Alternatively, instead of using a drum  40 , the reservoir  20  can be hung from a spring or other resilient member (not depicted), which will pull the reservoir  20  upward as it becomes lighter (due to removal of liquid product therefrom).  
         [0056]     Although the foregoing description contains many specifics, these should not be construed as limiting the scope of the present invention, but merely as providing illustrations of some of the presently preferred embodiments. Similarly, other embodiments may be devised which do not depart from the spirit or scope of the present invention. Features from different embodiments may be employed in combination. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions and modifications to the invention as disclosed herein which fall within the meaning and scope of the claims are to be embraced thereby.