MXPA99007641A - Shaving system including handle and replaceable cartridge - Google Patents

Abstract

A replaceable razor blade cartridge including a blade unit (16), and cartridge connecting structure for connecting the blade unit (16) to handle connecting structure of a handle (12), the cartridge connecting structure having inwardly directed surfaces (34) for mating with outwardly directed surfaces on the handle connecting structure, the blade unit (16) being pivotally connected to the cartridge connecting structure, the cartridge connecting structure including a latching member (44) that is movable to release the cartridge from the handle connecting structure prior to retraction of the cartridge connecting structure from the handle connecting structure.

Description

"SYSTEM FOR SHAVING, INCLUDING HANDLE AND REPLACEABLE CARTRIDGE" Background of the Invention The invention relates to shaving systems having disposable handles and cartridges. Shaving systems often consist of a handle and a disposable cartridge in which one or more razor blades are mounted in a protective plastic cover. After the razor blades of a cartridge become blunt due to use the cartridge is removed and replaced in the handle by a new cartridge. In some razors the blades are elastically mounted with respect to the cover of the cartridge and flex due to the force of contact with the skin during shaving. In some razors the connection of the cartridge to the handle facilitates the rotatable mounting of the cartridge with respect to the handle, so that the angle of the cartridge fits and can follow the contours of the surface being shaved. In these machines, the cartridge can be tilted to a rest position by means of a spring-loaded button (a cam follower), resting on the handle against a cam head in the protective cover of the cartridge. Summary of the Invention In one aspect, the invention generally discloses a disposable razor blade cartridge comprising a set of razor blades and a cartridge connecting structure for attaching the bundle of blades to a handle. The connection structure of the cartridge has internal surfaces that partially define a region where the handle is inserted and which engage with the external surfaces of the connection structure of the - REF .: 30977 handle in the handle. The connection structure of the handle also has an entrance that is attached to the region where the handle is inserted, and a nail that extends into that region. This nail has a blocking surface in the opposite direction to the connection inlet to hold the connection structure of the handle to the connection structure of the cartridge. In another aspect, the invention generally discloses a disposable razor blade cartridge comprising a set of razor blades that is rotatably attached to a cartridge connecting structure that has a latching mechanism that can be moved. to release the cartridge from the handle. In another aspect, the invention generally discloses a disposable razor blade cartridge having a set of razor blades and a connecting structure of the cartridge for connecting that bundle of blades with and for removing it from a handle by a movement as described above. along an axis of action. The connection structure of the handle comprises a latching mechanism that can be moved to release the cartridge from the handle before -removing the connecting structure of the handle cartridge along the coupling shaft. Certain applications of the invention have one or more of the following characteristics. In certain applications the hooking mechanism has a fingernail with a locking surface which prevents the connecting structure of the handle from separating from the connecting structure of the cartridge when it is in the hooking position and makes the connection structure easier. of the handle is separated from the connecting structure of the cartridge when it is in the reverse position. The latching mechanism comprises a coupling structure that can be moved from an initial position to a flexed position, and the locking surface moves from the latching position to the reverse position while the coupling structure Masito moves from the initial posjción to the posda? i Gex zeda. The nail can generally be pushed along a flexing axis transverse to the axis of the joint, and the nail has a cam surface on the side opposite the axis of flexion of the locking surface, and the cam surface It forms a greater angle with the axis of bending than the blocking surface. The trigger mechanism has a cantilever structure with a base region and a free end.; the nail is closer to the region of the base than the -coupling structure, and the coupling structure is closer to the lower end than the blocking surface. The connection structure of the handle on the handle has an ejector - which extends from the handle, and the coupling structure is aligned with the ejector. The coupling structure is at the free end of the cantilever structure, and the free end is curved in such a way that the nail is flexed in the direction transverse to the movement of the ejector when the coupling structure is activated by the ejector . -The angle of the blocking surface with the bending axis is between 0Q and -10Q; and the angle of the cam surface with the bending axis is between 30Q and 60Q. There are two nails, and two curved ends powered by the ejector. There are two slots that separate the cantilever structure from the adjacent portions of the cartridge connection structure. There are two notches that extend from the two grooves in the base region. The sections in the planes transverse to the coupling shaft that traverses the internal surfaces and the external surfaces that mate with those have asymmetric shapes to facilitate correct alignment during the coupling. In another aspect, the invention generally descs shaving machines with cartridges, such as those descd above, and with handles attached to the cartridges. In another aspect, the invention relates in general to methods for attaching disposable cartridges, such as those descd above, to handles, and for removing the cartridges from the handles by moving latching mechanisms to release the cartridges from the handles. The configurations of the invention may have one or more of the following advantages. The use of a latching mechanism allows the cartridge to be attached firmly to the handle, and is unlikely to be accidentally released during use. In addition, the cartridge can be soldered and removed from the handle without force when it is needed to be replaced. Other features and advantages of the invention will become apparent from the following description of its configurations and the claims. BRIEF DESCRIPTION OF THE FIGURES Fig. 1 is a perspective view of a razor according to the invention. Fig. 2 is a perspective view showing a handle and a disposable cartridge of the razor of Fig. 1, separated by -yes.

Fig. 3 is a partial section, taken in 3-3 of Fig. 6, of a cartridge connecting structure of the disposable cartridge of Fig. 2. Fig. 4 is a partial section of a connecting structure of the container. Fig. 5 is a partial elevation view of the connection structure of the cartridge of Fig. 3. Fig. 6 is a partial section, taken in-d of Fig. 5, of the connection structure of the cartridge of Fig. 3. Figs. 7-11 are schematic partial sections of portions of the connection structure of the cartridge of Fig. 3, and portions of the connection structure of the handle of Fig. 4, at different times of coupling and decoupling. Description of the Preferred Embodiments. With respect to Figs. 1 and 2, the shaver 10 comprises a handle 12 and a disposable cartridge 14. As shown in Fig. 2, the cartridge 14 can be removed from the handle 12. The cartridge 14 has a bundle of razor blades 16. , with three blades bent by a spring 18, a shield 20 and a cover 22. The cartridge 14 also comprises an interconnection mechanism 24 on which the razor blade assembly 16 is rotatably mounted. The interconnection element 24 comprises of a base 27 that can be removed from, and firmly attached to, the asymmetric extension 26 on the handle 12, and two arms 28 that rotatably support the razor blade assembly 16 on its two sides. The base 27 acts as a connection structure of the cartridge, and the extension 26 acts as a connection structure of the handle. These two structures are connected to each other so as to attach a disposable cartridge 14 to a handle 12. The spring button 45 extends from the extension 26, passes through an opening in the upper part of the base 27 and acts against the surface. of cam 30 in the set of razor blades 16, such that it is inclined forward when in the rest position, as described in detail in the application mentioned above, which is embodied by reference. With respect to Figs. 3 and 4, the base 27 has a region 32 in which the handle is inserted which is partially defined by the internal surfaces 34. The coupling inlet 36 allows access to the region 32 where the handle is inserted. The internal surfaces 34 engage the external surfaces 38 in the extension 26 of the handle 12. The base -27 also has an inclined recess 40 where the inclined surface 42 is inserted in the handle 12. With respect to Figs. 3, 5 and 6, the base 27 has a latching mechanism 44 formed in its lower wall 46. As shown in Figs. 3 and 6, the latching mechanism 44 has a carti lever structure, and is fixed to the lower wall 46 in the region of the base 48 near the ends of the slots 50. The latch mechanism 44 tends to rotate on the shaft 52 (Fig. 6) when subjected to a force with an external component at the free end of the coupling mechanisms 54 (ie, to the left along the coupling shaft 76 in Fig. 3). The lower wall 46 also has notches 56 (Figs 3, 6) that extend towards the slots 50 to facilitate rotation of the latch mechanism 44.

Two claws 58 (Figs 3, 5 and 6) extend upwards of the latching mechanism 44 so as to interact with the depressions 60 formed in the lower surface of the extension 26 of the handle 12 (Fig.4). Each -nail has an anterior locking surface 62, an upper surface 64, and an inclined cam surface 66, which forms an angle of 455 with the coupling shaft 76 along which the Drolongation 25 is displaced when attached. ay removed from the base 27. Other angles can also be used, for example, between 30Q and 609. Similarly, the depressions 60 have front surfaces 68 that interact with the anterior locking surface 62, the upper surface 70 and the inclined rear surface 72, for receiving the upper surface 64 and the cam surface 66, respectively, of the fingers 58. The front locking surface 62 of the finger 58 forms an angle of 909 with the coupling shaft 76.

With respect to Fig. 4, the ejector 79 is releasably mounted in the recess 81 within the connection structure of the handle 12. This ejector is illustrated in the rest position in Fig. 4, and may be pushed forward slightly by pressing button 80 on handle 12 - (See Figs 2 and 9-11). With respect to Figs. 9-11, the button 80 has a lower extension 82 that is inserted into the opening 84 of the -eyector 79. By pressing the button 80 forwardly relative to the extension 26 on which it is mounted (i.e. left in Fig. 9), the ejector 79 moves forward, from the position of Fig. 9 to the position of Figs. 10 and 11. Fig. 11 shows the front surface of the extension 82 against the abutment surface 86 of the pro-extension 26.

Figs. 7-11 are sections showing the components of the handle 12 and the cartridge 14 interacting during connection and removal of the carriage 14 with / of the handle 12. The components of the handle-connection structure illustrated in these figures are part of a subset that includes the extension 26; the rest of the sub-assembly is inserted in the handle 12 and therefore is not illustrated in Fig. 2. With respect to Fig. 7, the extension 26 of the handle 12 is illustrated in an advanced position along the coupling axis 76. in the insertion direction 1 indicated by the arrow. It can be seen that the extension 26 is inserted into the region 32 where the handle of the base 27 is inserted. As shown in FIG. 7, the button 80 is in the rest position, and the lower inclined anterior surface 90 of the prologue 26 is about to come into contact with the cam surface 66 - of the nail 58. With respect to Fig. 8, while the extension 26 of the handle 12 continues to be displaced in the direction of insertion indicated by the fie 1, the inclined surface 90 of the extension 26 overlaps with the cam surface 66, and causes the latching mechanism 44 and, in particular, the nail 58 thereof, to move downward along the - Bending axle indicated by the arrow D which is perpendicular to the coupling axis 76 and the direction of insertion 1. The action of the inclined surface 90 on the cam surface 66 causes the latch mechanism 44 to be generally bent on the axis 52 in the base region. - (See Figs 6 and 8) In the position illustrated in Fig. 8, the lower portion of the inclined surface 90 is shown as superimposed on the upper surface 64 of the nail 58. Due to the surface inclined 90 and the cam surface 66, relatively smaller coupling forces are required to flex the latching mechanism 44 and to connect the cartridge 14 to the handle 12. With respect to FIG. 9, the extension 26 of the handle 12 is shown in the position in which it is attached to the base 27 of the cartridge 14. The inclined surface 90 is advanced beyond the nail 58, and the latching mechanism 44 is moved upward to the latching position in which the nail 58 fits within the depression 60 of the extension 26. In this position the cartridge 14 is firmly attached to the handle 12, and is little-likely to be accidentally released during use due to the action of the surface 68 on the handle 12, and the surface of blocking 62 on the cartridge 14. The surfaces 62 and 68 are perpendicular to the axis 76 to which the extension 26 needs to move relative to the base 27 to disconnect the two. In this way, it would be necessary to exert a very large force along the axis 76 to disconnect the carriage 14 from the handle 12 if the latching mechanism 44 is not released first.

With respect to Fig. 10, when the user wants to release the cartridge 14 from the handle 12, the button 80 is pushed relative to the extension 26 in the direction of disengagement indicated by the arrow U in Fig. 10. This causes the ejector 79 to move along the axis 76 in the ejection direction indicated by the arrow E. The ejector 79 pushes the coupling mechanisms 54 outwardly., and causes the nail 58 to move downward in the direction of flexion indicated by the arrow D, while the latching mechanism 44 is curved on the axis 52 in the region of the -base 48. This downward movement causes the nail 58 moves out of depression 60 and releases the extension 26 of hook mechanism 44, so that extension 26 moves relative to base 27 in the retraction direction indicated by arrow R. As shown in FIG. the -Fig. 10, the extension 82 of the button 80 is advanced from the position shown in Fig. 9. In Fig. 11, the button 80 continues to move forward, and the extension 82 is against the stop surface 85. The extension 26 it continues to move in the retraction direction R in such a way that the front inclined surface 90 moves downwardly on the camming surface 66. While the extension 26 continues to be removed from the base 27, the ejector 79 will eventually move backwards from coupling mechanisms 54, which allows latching mechanism 44, - to return to the uncoupling position at rest shown in Fig. 7. Other configurations of the invention are within the framework of the following claims. For example, the blocking surface 62 and / or the anterior surface 68 of the extension 26 could form an angle slightly smaller than 90s (eg, between 809 and 909) with respect to the coupling shaft 76 to allow the base 27 to be decoupling the extension 26 after being subjected to a force that is substantially greater than the forces to which the pieces would be subjected during a common shaving. This force could also be greater than the forces required to attach a cartridge 14 to a handle 12. When the nail locking surface extending inward from the base 27 is slanted, it can be avoided to use a latching mechanism that needs to be flexed before being removed, as described in the previous application; in this case, the base 27 will deform during the removal to allow the nail to move out of the depression in the extension of the handle. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention.

Claims (35)

1. In the foregoing, the invention is claimed as property contained in the following: claims: 1. A disposable razor blade cartridge, comprising: a set of razor blades, and a connecting structure of the cartridge for attaching that set of razor blades to a connecting structure of the handle in a handle; said connection structure of the cartridge has inwardly facing surfaces engage with surfaces that are directed outwardly in said connection structure of the handle; said connection structure of the cartridge has a region that receives the handle defined partially by the surfaces that go inwards as well as a connection entrance - which is attached to the region receiving the handle; said connecting structure of the cartridge includes a nail extending into the receiving region of the handle and having a locking surface in the opposite direction to the connecting inlet for holding the connecting structure of the handle with the connecting structure of the cartridge.
2. 2. A disposable razor blade cartridge, characterized in that it comprises: a set of razor blades, and a connecting structure of the cartridge for attaching said set of blades to the connecting structure of the handle, and that assembly of The leaves are rotated to the connecting structure of the cartridge; the connecting structure of the cartridge has a latching mechanism that moves to release said cartridge from said handle connection structure.
3. 3. A disposable razor blade cartridge, characterized in that it comprises a set of razor blades, and a connection structure of the cartridge for attaching said set of blades to a connection structure of the handle and for removing it from it by a movement along a coupling axis; the connecting structure of the cartridge has a latching mechanism that moves to release the cartridge from the connecting structure of the handle, before retracting the connecting structure of the cartridge from the connecting structure of the handle cartridge along the axis of the cartridge. coupling
4. 4. The cartridge of claim 1, characterized in that the set of razor blades is attached rotatably to the connection structure of the cartridge.
5. 5. The cartridge of claim 1, characterized in that the - connection structure of the cartridge has a latching mechanism that is moved to release the cartridge from the connection structure of the handle, and -the nail is in the mechanism of hitch.
6. 6. The cartridge of claim 3, characterized in that the latch mechanism has a blocking surface that prevents said handle connection structure from being released from the cartridge connecting structure when in the hooked position, and facilitates that the connection structure of the handle is released from the connection structure of the cartridge when it is not in the engaged position.
7. 7. The cartridge of claim 6, characterized in that the coupling mechanism comprises a coupling structure that moves from an initial position to a flexed position; the locking surface moves from the engaged position to the inverse position while the coupling structure moves from the initial position to the flexed position.
8. 8. The cartridge of claim 7, characterized in that the blocking surface is in a nail of the hooking mechanism.
9. 9. The cartridge of claim 8, characterized in that the -nail moves generally along an axis of transverse bending to the coupling axis, and the nail has a cam surface on the opposite side of the bending axis. of the blocking surface, the cam surface - forms a greater angle with the axis of bending than the blocking surface.
10. 10. The cartridge of claim 7, characterized in that the latching mechanism has a cantilever structure with a base region and a free end.; the locking surface is closer to the region of the base than the coupling structure, and the coupling structure is closer to the free end than the blocking surface.
11. 11. The cartridge of claim 7, characterized in that the connection structure of the handle has an ejector extending from there, and the coupling structure is aligned with the ejector when the handle is attached to the cartridge.
12. 12. The cartridge of claim 10, characterized in that the connection structure of the handle has an ejector extending therefrom, and the coupling structure is aligned with the ejector when the handle is attached to the cartridge.
13. 13. The cartridge of claim 12, characterized in that the coupling structure is at the free end, and the free end is curved in such a way that the blocking surface is flexed in -direction transverse to the movement of the ejector when the structure The coupling is activated by the ejector.
14. 14. The cartridge of claim 6, characterized in that the connection structure of the cartridge has internal surfaces that are coupled with external surfaces in said connection structure of the handle; wherein said connection structure of the cartridge has a region where the handle is partially defined by the surfaces that are directed inwards as well as an entrance that is attached to the region where the handle is inserted, and the coupling shaft passes. through the entrance of acé plamiento; and wherein said latching mechanism has a nail extending from within the region where the handle is inserted; the blocking surface is located on that nail, in the opposite direction to the coupling inlet, for holding the connecting structure of the handle to said connecting structure of the handle to said connecting structure of the cartridge.
15. 15. The cartridge of claim 14, characterized in that the latching mechanism comprises a coupling structure that moves from an initial position to a flexed position; the locking surface moves from the engaged position to said inverse position while said assembling structure moves from the initial position to the flexed position.
16. 16. The cartridge of claim 15. characterized in that the nail moves generally along a transverse axis of flexion to said coupling axis, and said nail has a cam surface on the opposite side of the flexure axis. of said blocking surface; said cam surface forms a greater angle with the axis of flexion than said blocking surface.
17. 17. The cartridge of claim 9, characterized in that the angle of said blocking surface with the bending axis is between O9 and 109.
18. 18. The cartridge of claim 16, characterized in that the angle of the blocking surface with The axis of flexion is between O9 and 109.
19. 19. - The cartridge of claim 17 or 18, characterized in that the angle of the cam surface with the bending axis is between 309 and 609.
20. 20. The cartridge of claim 15, characterized in that - the latching mechanism has a Cantilever structure with a base region and a free end; the locking surface is closer to the base region than the coupling structure, and the coupling structure is closer to the free end than the blocking surface.
21. 21. The cartridge of claim 20, characterized in that the connection structure of the handle has an ejector extending therefrom, and the coupling structure is aligned with said ejector when the handle is attached to said cartridge.
22. 22. The cartridge of claim 21, characterized in that the ejector travels along said coupling axis, and said coupling structure is at said free end; said free end is curved in such a way that said nail is bent in the transverse direction when it is driven by said ejector.
23. 23. - The cartridge of claim 22, characterized in that it comprises two nails.
24. 24. The cartridge of claim 23, characterized in that - there are two curved ends driven by the ejector.
25. 25. The cartridge of claim 20, characterized in that it comprises two grooves that separate the cantilever structure from the adjacent portions of said cartridge connecting structure.
26. 26. The cartridge of claim 25, characterized in that there are two notches extending from the two grooves in said region of the base.
27. 27. The cartridge of claim 1, characterized in that the connection structure of the cartridge has a coupling axis that passes through that coupling axis and into said region where the handle is inserted, and in which a cross section passes through. said surfaces that are directed inwards in a plane transverse to said coupling axis is asymmetric.
28. 28. The cartridge of claim 7, characterized in that the coupling structure has two portions that are adapted to be attached by an ejector on said handle.
29. 29. The cartridge of claim 7 or 28, characterized in that the hooking mechanism has a second locking surface that -blocks the retraction of said connection structure of the handle of said cartridge-connection structure when in the position of hooking, and allows the retraction of said connecting structure of the handle of said cartridge connecting structure when it is not in hooked position.
30. 30.- A razor, characterized in that it comprises a handle with a connection structure of the cartridge with surfaces that are directed towards the outside and a depression in that surface that is directed towards the outside and a disposable cartridge that has: a set of razor blades, and a connecting structure of the cartridge for attaching that set of razor blades to said connecting structure of the handle of a handle; said cartridge connection structure has inwardly facing surfaces that mate with outwardly directed surfaces; said connection structure of the cartridge has a region where the handle is partially defined by said surfaces that are directed inwards as well as an entrance that is attached to the region where the handle is inserted; said connection structure of the cartridge has a nail that extends inside the region where the handle is inserted and inside said depression and has a blocking surface in the opposite direction to said connection inlet to hold said connection structure of the handle with said connection structure of the cartridge.
31. 31. A razor characterized in that it comprises: a handle with a connecting structure of the cartridge, and a discarded cartridge having: a set of razor blades, and a connecting structure of the cartridge for attaching that joint of leaves to a connection structure of the handle, and that set of leaves is attached rotatably to the connection structure of the cartridge; the connection structure of the cartridge has a latching mechanism that moves to release the cartridge from the connection structure of the handle.
32. 32. A razor, comprising; a handle with a connection structure of the cartridge, and a disposable cartridge that has: a set of razor blades, and a connecting structure of the cartridge for attaching and removing that set of blades to / from a connecting structure of the handle by a movement along a coupling shaft. said connection structure of the cartridge has a latching mechanism that can be moved to release said cartridge from the connection structure of the handle, before removing said connecting structure from the cartridge of the connecting structure of the handle along said axis of connection. coupling
33. 33. The razor of claim 32, wherein the latching mechanism has a locking surface that prevents the connecting structure of said handle from being released from said connecting structure of the cartridge when in the engaged position. and it facilitates that said connection structure of the handle is released from said connecting structure of the cartridge when it is not in the engaged position.
34. 34. The razor of claim 33, wherein said engaging mechanism comprises a coupling structure that moves from an initial position to a flexed position, said block-surface moving from the engaging position to the inverse position while said coupling structure moves from the initial position to the flexed position.
35. 35.- The razor of claim 34, characterized in that the locking surface is in a nail of the hooking mechanism. 3 - The razor of claim 35, characterized in that the nail moves generally along an axis of flexion transverse to the coupling axis, and said nail has a cam surface on the opposite side of the axis of flexion of said locking surface, the cam surface forms a greater angle with said axis of bending than the blocking surface. 37.- The razor of claim 34, characterized in that the hooking mechanism has a cantilever structure with a base region and a free end; the blocking surface is closer to the region of the base than the coupling structure, and the coupling structure is closer to the free end than the blocking surface. 38.- The razor of claim 34, characterized in that the connection structure of the handle has an ejector extending therefrom, and said coupling structure is aligned with the ejector when said handle is attached to the cartridge. 39.- The razor of claim 34, characterized in that the connection structure of the handle has an ejector, and the coupling structure has two portions that are actuated by the ejector. 40. The razor of claim 34 or 39, characterized in that the latch mechanism has a second locking surface that blocks the retraction of the handle connecting structure from the connecting structure of said cartridge when it is in the position of engaging che, and allows the retraction of said connection structure of the handle of said connection structure of said cartridge when it is not in the engaged position. 41. A method for attaching a cartridge to a handle, characterized in that it comprises: providing a cartridge of disposable razor blades having a set of razor blades, and a connecting structure of the cartridge for attaching that set of razor blades to a connection structure of the handle of a handle; said connecting structure of the cartridge has surfaces that are directed inwards that engage surfaces-which are directed outwards; said connection structure of the cartridge has a region where the handle is partially defined by the internal surfaces as well as an entrance that is attached to the region where the handle is inserted; said connection structure of the cartridge has a nail extending inside the region where the handle is inserted and has a blocking surface in the opposite direction to the connection inlet to hold the connecting structure of the handle with the connecting structure of the handle. --cartucho, and connect a handle to this cartridge. 42. A method for removing a cartridge from a handle, characterized in that it comprises: providing a cartridge of disposable razor blades having a set of razor blades, and a connecting structure of the cartridge for attaching that set of blades to a connection structure of the handle, and that set of leaves is attached rotatably to the structure-connection of the cartridge; said connecting structure of the cartridge has a latching mechanism that moves to release the cartridge from the connecting structure of the handle, and a handle connected to that cartridge; move the latching mechanism to release that cartridge from the handle; and remove the cartridge from the handle. 43.- A method for attaching a cartridge to a handle, characterized in that it comprises: providing a disposable razor blade cartridge having a set of razor blades, and a connecting structure of the -cartridge to attach and remove that assembly of leaves to / from a handle connection structure by a movement along a coupling shaft; The connection structure of the cartridge has a latching mechanism that moves to release said cartridge from said connecting structure of the handle before removing said connecting structure from the cartridge of said connecting structure of the handle cartridge along said axis. of coupling, and a handle attached to that cartridge; moving said hooking mechanism to release said cartridge from the handle and then removing said cartridge from the handle while rowing to see the connecting structure of the cartridge of said handle connection structure along said coupling axis.