Patent Publication Number: US-10787853-B2

Title: Integrated casement window operator and lock with anti-backdrive feature

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/548,260, filed Aug. 21, 2017, and entitled INTEGRATED CASEMENT WINDOW OPERATOR AND LOCK WITH ANTI-BACKDRIVE FEATURE, and also claims the benefit of U.S. Provisional Patent Application No. 62/660,135, filed Apr. 19, 2018, and entitled INTEGRATED CASEMENT WINDOW OPERATOR AND LOCK WITH ANTI-BACKDRIVE FEATURE, both said applications being fully incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The instant invention relates to casement windows, and in particular operators and locks for casement windows. 
     BACKGROUND 
     A casement window is a window that has a sash attached to a frame with hinges so that the sash can swing in and out to close or open the opening defined by the frame. Casement windows have certain advantages over sliding windows, such as double-hung or sideways sliding windows. In particular, sliding windows can be difficult to seal against air infiltration, since the sash must slide against the air sealing gasket or weather stripping. This often means that the sliding sash is not fitted as tightly, and the materials used for sealing selected so as to avoid excessive friction and wear. Casement sashes, however, can swing into contact with the seal, thereby avoiding any friction and causing minimal wear of the seal. 
     A drawback of casement windows, however, is that an operator typically must be used. An example of a typical operator used with a casement is disclosed in U.S. Pat. No. 7,464,619, said patent being hereby fully incorporated herein by reference. Such complex operators add expense and complexity to the window. Further, casement windows typically have separate locking systems to provide security against unauthorized access. These systems can add complexity to window operation as well as expense. These factors have led to casement windows being used less frequently in low-cost construction. 
     Prior attempts have been made to provide a simple integrated casement operator that incorporates both operation and locking functions in a single device. An example is the device described in. U.S. patent application Ser. No. 15/403,466, now U.S. Pat. No. 10,221,607, entitled INTEGRATED CASEMENT WINDOW OPERATOR AND LOCK, hereby fully incorporated herein by reference. Drawbacks of this device, however, are that it can be prone to back-driving thereby enabling unauthorized access through the window, and the hook arrangement for securing the locking point detracts from the aesthetic appearance of the device. 
     What is still needed in the industry is a simple casement operator that integrates the locking function in one device and that addresses the drawbacks identified above. 
     SUMMARY 
     Embodiments of the present invention address the need in the industry is a simple casement operator that integrates the locking function in one device and that addresses the drawbacks identified above including providing anti-backdriving features. According to an embodiment, an integrated casement window operator and lock includes a gear mechanism, the gear mechanism including a housing, a pinion gear rotatably mounted to the housing, and an arm assembly including an arm and a sash interface link. The arm defines a rack portion and an adjacent arcuate gear portion, and the arm is slidably and rotatably mounted to the housing with the pinion gear engaged with the rack portion and the arcuate gear portion. The pinion gear defines a star-shaped aperture therethrough, the star-shaped aperture defined by a plurality of inwardly facing surfaces, each of the inwardly facing surfaces comprising a pair of bearing surfaces on opposite sides of a central ridge. The gear further defines a pair of spaced-apart slots, the slots extending outwardly from a separate one of the pair of bearing surfaces of one of the inwardly facing surfaces. The housing defines an arc-shaped slot with notches at opposing ends of the arc-shaped slot. 
     The device further includes a pair of anti-backdrive pin assemblies, each of the anti-backdrive pin assemblies slidably disposed in a separate one of the spaced-apart slots of the gear and including an anti-backdrive pin, each of the anti-backdrive pins engaged in the arc-shaped slot. A handle defines a square-shaped shaft portion, the square-shaped shaft portion received in the star-shaped aperture of the gear, wherein the handle is selectively movable to rotate the pinion gear such that the arm is shifted between a window fully closed position and a window fully open position, wherein when the arm is in the fully closed position, the pin of a first one of the pair of anti-backdrive pin assemblies is engaged in one of the notches of the arc-shaped slot to inhibit backdriving of the arm, and when the arm is in the fully open position, the pin of a second one of the pair of anti-backdrive pin assemblies is engaged in the other one of the notches of the arc-shaped slot to inhibit backdriving of the arm. The square-shaped shaft portion of the handle is rotatable in the star-shaped aperture of the gear to shift the anti-backdrive assemblies out of engagement with the notches. 
     In an embodiment, at least one biasing spring is arranged to urge the anti-backdrive pins into engagement with the notches. The at least one biasing spring may be a leaf spring. 
     In an embodiment, a pair of biasing springs is arranged to urge the anti-backdrive pins into engagement with the notches. Each one of the pair of biasing springs may be a coil spring, or the pair of biasing springs may be formed as a portion of an actuating ring. 
     In an embodiment, the anti-backdrive pin assemblies may include a follower portion and a pin portion. The follower portion may have a wedge-shaped end. 
     In an embodiment, the square-shaped shaft portion of the handle defines four faces, one of the four faces defining a pair of spaced apart notches, the wedge-shaped ends of the follower portions being engageable in the notches in the face. 
     In an embodiment, a casement window includes a frame defining an opening, a sash received in the frame and hinged to the frame to selectively close the opening, and a window operator and lock. The window operator and lock includes a gear mechanism, the gear mechanism including a housing, a pinion gear rotatably mounted to the housing, and an arm assembly including an arm and a sash interface link. The arm defines a rack portion and an adjacent arcuate gear portion, and the arm is slidably and rotatably mounted to the housing with the pinion gear engaged with the rack portion and the arcuate gear portion. The pinion gear defines a star-shaped aperture therethrough, the star-shaped aperture defined by a plurality of inwardly facing surfaces, each of the inwardly facing surfaces comprising a pair of bearing surfaces on opposite sides of a central ridge. The gear further defines a pair of spaced-apart slots, the slots extending outwardly from a separate one of the pair of bearing surfaces of one of the inwardly facing surfaces. The housing defines an arc-shaped slot with notches at opposing ends of the arc-shaped slot. 
     The operator further includes a pair of anti-backdrive pin assemblies, each of the anti-backdrive pin assemblies slidably disposed in a separate one of the spaced-apart slots of the gear and including an anti-backdrive pin, each of the anti-backdrive pins engaged in the arc-shaped slot. A handle defines a square-shaped shaft portion, the square-shaped shaft portion received in the star-shaped aperture of the gear, wherein the handle is selectively movable to rotate the pinion gear such that the arm is shifted between a window fully closed position and a window fully open position, wherein when the arm is in the fully closed position, the pin of a first one of the pair of anti-backdrive pin assemblies is engaged in one of the notches of the arc-shaped slot to inhibit backdriving of the arm, and when the arm is in the fully open position, the pin of a second one of the pair of anti-backdrive pin assemblies is engaged in the other one of the notches of the arc-shaped slot to inhibit backdriving of the arm. The square-shaped shaft portion of the handle is rotatable in the star-shaped aperture of the gear to shift the anti-backdrive assemblies out of engagement with the notches. 
     The above summary is not intended to describe each illustrated embodiment or every implementation of the subject matter hereof. The figures and the detailed description that follow more particularly exemplify various embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Subject matter hereof may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying figures, in which: 
         FIG. 1 a    depicts a casement window and integrated operator according to an embodiment of the invention; 
         FIG. 1  is a partial exploded view of the integrated operator depicted in  FIG. 1   a;    
         FIG. 2  is a side elevation view of the integrated operator depicted in  FIG. 1  in a window open position; 
         FIG. 3  is a side elevation view of a portion of the housing of the integrated operator depicted in  FIG. 1 ; 
         FIG. 4  is a side elevation view of the integrated operator of  FIG. 1  in a window closed position with the gear portion free to rotate; 
         FIG. 5  is a side elevation view of the integrated operator of  FIG. 1  in a window closed position with the gear portion engaged with the anti-back-drive mechanism engaged to prevent rotation; 
         FIG. 6  a side elevation view of the gear portion of the integrated operator of  FIG. 1 ; 
         FIG. 7  is a side elevation view of the gear portion of the integrated operator of  FIG. 1  with the anti-back-drive mechanism engaged to prevent rotation; 
         FIG. 8  is a side elevation view of the gear portion of the integrated operator of  FIG. 1  with the anti-back-drive mechanism disengaged; 
         FIG. 9  is an isometric view of the rear side of the cover of the integrated operator of FIG.  1 ; 
         FIG. 10  is a partial side sectional view of the cover of the integrated operator depicted in  FIG. 9 ; 
         FIG. 11  is an isometric view of the integrated operator of  FIG. 1  with the cover depicted in phantom; 
         FIG. 12  is a partial sectional view of the integrated operator of  FIG. 11  depicting the engagement of the cover with the housing; 
         FIG. 13  is a partial side elevation view of the integrated operator of  FIG. 1  depicting the engagement of the housing with a window profile; 
         FIG. 14  is a partial side elevation view of the integrated operator of  FIG. 1  depicting the engagement tabs of the housing in a retracted position; 
         FIG. 15  is a partial side elevation view of the integrated operator of  FIG. 1  depicting the engagement tabs of the housing in an extended position; 
         FIG. 16  is a rear isometric view of the integrated operator of  FIG. 1  with the engagement tabs in a retracted position; 
         FIG. 17  is a rear isometric view of the integrated operator of  FIG. 1  with the engagement tabs in an extended position; 
         FIG. 18  is a partial isometric view of the integrated operator of  FIG. 1  with a portion of the housing depicted in phantom to show engagement of the arm in a slot in the housing; 
         FIG. 19  is a partial isometric view of a portion of the housing of the integrated operator of  FIG. 1 ; 
         FIG. 20  is an isometric view of the handle assembly of the integrated operator of  FIG. 1 ; 
         FIG. 21  is a partial sectional view of the integrated operator of  FIG. 1 ; 
         FIG. 22  is an exploded view of an alternative embodiment of an integrated operator in which the anti-backdrive pins are urged by a single leaf spring; 
         FIG. 23  depicts the gear portion of the embodiment of  FIG. 22 ; 
         FIG. 24  is a plan view depiction of the gear portion of another alternative embodiment of the invention; 
         FIG. 25  is an exploded view of the embodiment of  FIG. 24 ; 
         FIG. 26  is an isometric view of the handle shaft of the embodiment of  FIG. 24   
         FIG. 27  is a partial isometric view of the embodiment of  FIG. 24 , with the gear portion omitted to show the actuating rings of the device; 
         FIG. 28  is a partial isometric view of the embodiment of  FIG. 24  depicted in the window closed and locked position; 
         FIG. 29  is a close up view of the gear portion of the mechanism depicted in  FIG. 28 ; 
         FIG. 30  is a partial isometric view of the embodiment of  FIG. 24  depicted in the window closed and unlocked position; 
         FIG. 31  is a close up view of the gear portion of the mechanism depicted in  FIG. 30 ; 
         FIG. 32  is a partial isometric view of the embodiment of  FIG. 24  depicted in the window open and secured in place by the anti-backdrive pins; 
         FIG. 33  is a close up view of the gear portion of the mechanism depicted in  FIG. 32 ; 
         FIG. 34  is a partial isometric view of one of the housing halves of the embodiment of  FIG. 24  with the gear omitted to show the actuating ring securement to the housing half; and 
         FIG. 35  is a partial isometric view of one of the housing halves of the embodiment of  FIG. 24  with the gear and actuating ring omitted. 
     
    
    
     While various embodiments are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the claimed inventions to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     In  FIG. 1 a   , there is depicted a typical casement window  10  with an integrated operator and lock  12  according to an embodiment of the invention. Casement window  10  generally includes frame  14  and sash  16 . Frame  14  defines opening  18 . Sash  16  is mounted to frame  14  with hinges (not depicted), and can be selectively swung to open and close opening  18 . 
     Integrated operator and lock  12  is depicted in  FIGS. 1-21 . Integrated operator and lock  12  generally includes gear mechanism  20 , handle  22 , and cover  24 . Gear mechanism generally includes housing  101 , comprised of housing halves  100 ,  102 , pinion gear  104 , and arm assembly  106 . Housing half  100  defines channel  108  and guide pin  110 . Housing half  102  can define a channel (not depicted) corresponding to channel  108  and an aperture  109  corresponding to guide pin  110 . 
     Housing half  100  further defines arc-shaped channel  112 , and housing half  102  defines a corresponding arc-shaped channel (not depicted). Mating pins  114  defined by housing half  100  are received in apertures  116  in housing half  100 . Arc shaped channel  112  has notches  118  at each end. 
     Gear  104  defines teeth  120  along a portion of periphery  122 . Star-shaped aperture  124  is defined through the center of gear  104  by inwardly facing surfaces  123 . Referring to  FIGS. 6 and 23 , corners  126  of aperture  124  are relieved, forming a central ridge  128  in each of sides  130 ,  132 , of aperture  124 . Parallel slots  134  extend outwardly from aperture  124  toward periphery  122 . Bearing surfaces  135  are formed on opposite sides of central ridge  128 . 
     An anti-backdrive feature is provided through anti-backdrive assembly  134   a . Anti-backdrive assembly  134   a  generally includes anti-backdrive pins  136 , biasing springs  142 , and follower blocks  144 . Anti-backdrive assemblies  134   a  are received in slots  134 , with anti-back-drive pins  136  extending outwardly from each face  138 ,  140 , of gear  104 . Biasing springs  142  are provided to bias anti-back-drive pins  136  toward aperture  124 . Biasing springs  142  can be coil springs as depicted in  FIG. 1 , or can be any other type of biasing element that is effective to bias pins  136 , such as leaf spring  143  depicted in  FIGS. 22 and 23 . Follower blocks  144  are provided on the inner end of each slot  134  and are slidable in slots  134  with anti-back-drive pins  136 , with, or against, the bias of springs  142 . Anti-back-drive pins  136  ride in arc-shaped channel  112  of housing half  100  and/or housing half  102 . 
     Arm assembly  106  generally includes arm body  146  defining elongate aperture  148 . Gear teeth  150  are defined along a portion of peripheral edge  152 . Guide pin  154  extends outwardly and rides in channel  156  of housing half  100 . Guide pin  110  of housing half  100  extends through elongate aperture  148 . Arm extension  158  is fixedly coupled to arm body  146  with rivets  160 , and defines boss  162 . 
     Handle  22  generally includes finger grip portion  164  and square shaped shaft  166  presenting bearing faces  168 . Square shaped shaft  166  extends through star-shaped aperture  124  of gear  104  and is secured in place with screw  170  and washer  172 . It will be appreciated that bearing faces  168  contact central ridges  128 , but that the star-shape of aperture  124  enables shaft  166  to rotate slightly in each direction within aperture  124  before bearing faces  168  contact bearing surfaces  135 . In a preferred embodiment, the amount of this rotation is about 7.5 degrees. 
     Integrated operator and lock  12  is assembled with gear  104  rotatably received between housing halves  100 ,  102 , as depicted in  FIG. 1 . Anti-back-drive pins  136  are received in arc-shaped channel  112 . Arm assembly  106  is received between housing halves  100 ,  102 , with guide pin  110  through elongate aperture  148  and guide pin  154  engaged in channel  156 . Gear teeth  150  are meshed with teeth  120  of gear  104 . 
     In use, integrated operator and lock  12  is mounted on frame  14  of window  10  with end  174  of arm extension  158  coupled to sash  16 . In a window closed and locked position as depicted in  FIGS. 5, 18, and 21 , boss  162  of arm extension  158  is drawn into channel  108 , thereby inhibiting arm  106  from swinging outward and locking sash  16  in a closed position in frame  14 . As depicted in  FIG. 7 , one of anti-back-drive pins  136  is lodged in notch  118  by the bias of spring  142 , thereby preventing rotation of gear  104  to open sash  16 , except as initiated by rotation of handle  22  as will be described below. 
     When handle  22  is rotated in a counter-clockwise direction as depicted in  FIG. 8 , square shaped shaft  166  rotates within star-shaped aperture  124  until a bearing face  166  contacts a bearing surface  135 . Another bearing face  168  of shaft  166  bears against follower block  144  and urges anti-back-drive pin  136  out of notch  118  and into arc-shaped channel  112  against the bias of spring  142 . As handle  22  is rotated further in the counter-clockwise direction, gear  104  rotates with anti-back-drive pins  136  riding in arc-shaped channel  112 . As gear  104  rotates, arm assembly  106  is urged downwardly through the mesh of gear  104  with gear teeth  150 . Once boss  162  emerges from channel  108 , sash  16  is no longer locked within frame  14 . As handle  22  is rotated further, and gear  104  reaches curved portion  170  of arm  106 , arm  106  swings outwardly, guided by guide pin  154 , as depicted in  FIG. 2 , urging sash  16  to an open position. When in the fully open position, the other of anti-back-drive pins  136  drops into the other of notches  118  urged by the other of springs  142 , thereby preventing rotation of gear  104  until handle  22  is rotated in the clockwise direction. To close sash  16 , the direction of rotation of handle  22  is reversed. 
     It will of course be appreciated that integrated operator and lock  12  may be mounted so as to reverse the direction of movement of arm  106  from downward to upward, and the direction of rotation of handle  22  from counter-clockwise to clockwise during the opening operation. Also, it will be appreciated that although a square handle shaft and star-shaped gear aperture are described hereinabove, the same principles and functional operation can be effected with other shapes of each. Also, auxiliary arm  178  can be coupled to arm  106  to effect operation of additional remote locking points. 
     Another feature of embodiments of the invention is depicted in  FIGS. 13-17 . In particular, housing  101  can be mounted in hollow member frame  14  by means of mounting tabs  180 , driven by fasteners  182 . With tabs  180  in a retracted position as depicted in  FIG. 14 , integrated operator and lock  12  can be inserted through an aperture cut in a hollow frame member. Once in place, fasteners  182  are tightened as depicted in  FIG. 15 , simultaneously extending and moving tabs  180  upward so as to clamp a wall  184  of hollow frame  14  between tab  180  and flange  186 , thereby securing housing  101  in place. This feature increases the number of window profiles which the integrated operator and lock  12  will fit, from single wall aluminum profiles to vinyl profiles that have two walls that are spaced apart. 
     In  FIGS. 9-12  a further feature of embodiments of the invention is depicted. In particular, snap-on cover  190  can be provided which has spring hooks  192 . Spring hooks  192  can engage with notches  194  to enable cover  24  to snap on and off housing  101 . 
     A further embodiment including an alternative anti-backdrive arrangement is depicted in  FIGS. 24-35 . In this embodiment, anti-backdrive assemblies  200  generally include follower blocks  202 , anti-backdrive pins  204 , and actuator rings  206 ,  208 . Follower blocks  202  have wedge-shaped ends  210 , and anti-backdrive pins  204  are carried in the opposite end of follower blocks  202 . As described for the embodiments above, anti-backdrive assemblies  200  are received in slots  134  of gear  104 , with anti-back-drive pins  204  extending outwardly from each face  138 ,  140 , of gear  104  and riding in arc-shaped channel  112  of housing half  100  and/or housing half  102 . 
     As best depicted in  FIGS. 34 and 35 , actuator rings  206 ,  208 , generally include circular body portion  211 , which defines a pair of opposing leaf spring arms  212 ,  214 . Between each spring arm  212 ,  214 , and inner body portion  216  are slots  218 ,  220 , respectively with notches  222 ,  224 , defined at the outer ends of the slots. Each actuator ring  206 ,  208 , is fixed in rotational position relative to a respective housing half  100 ,  102 , with boss  226  and indexing key  228 . 
     In this embodiment, as depicted in  FIGS. 26 and 27 , square-shaped shaft  166  of handle  22  has notches  230  defined in one of bearing faces  168 . Notches  230  are shaped to receive wedge-shaped ends  210  of follower blocks  202 , and to facilitate shifting of follower blocks  202  as further described below. 
     In use, with the integrated operator in the closed and locked position as depicted in  FIGS. 28 and 29 , spring arm  214  urges one of the anti-backdrive pins  204  into notches  224  and  118 , thereby engaging wedge-shaped end  210  of the coupled follower block  202  into one of the notches  230  in square-shaped shaft  166  of handle  22 . In this position, arm assembly  106  cannot be back-driven to rotate handle  22 , and thereby unlock and open the window, since the anti-backdrive pin  204  is held in both notches  224  and  118  against rotation and is urged into engagement therewith by spring arm  214 . 
     From this position, as depicted in  FIGS. 30 and 31 , when handle  22  is rotated counter-clockwise relative to the figures, wedge-shaped end  210  slides along the tapered surfaces of notch  230 , thereby urging follower block  202  outward against the bias of spring arm  214 . Accordingly, anti-backdrive pin  204  is shifted out of engagement with notches  224  and  118  and into arc-shaped channel  112 , where the handle and mechanism can be freely shifted in either direction with handle  22 . 
     As depicted in  FIGS. 32 and 33 , further counter-clockwise rotation of handle  22  will cause arm assembly  106  to swing outward, thereby opening sash  16  of casement window  10 , and will cause the other of anti-backdrive pins  204  to contact and thereby be guided and urged by spring arm  212  into engagement with notch  222  and notch  118  at the other end of arc-shaped channel  112 . In this position, arm assembly  106  cannot be back-driven by wind or other forces to rotate handle  22 , since the anti-backdrive pin  204  is held in both notches  222  and  118  and is urged into engagement therewith by spring arm  212 . When it is desired to close casement window  10 , handle  22  can be rotated clockwise, thereby reversing the sequence described above. 
     Advantages of various embodiments of the invention can be as follows:
         A positive detent provided by the anti-backdrive pin assemblies in the window open and closed positions can provide an audible click when the operator is in the fully open position and in the fully closed and locked position.   The anti-backdriving feature can prevent wind buffeting from slamming the window shut when the device is in the fully open position.   The described mounting method enables the operator to be applied to a wide variety of window profiles.   The described mounting method enables screws to be driven into a window from the same side as the operator is installed in the cut out.   The described mounting method enables access to the screw heads in the case of a hardware failure where the window has become stuck shut without cutting into the window frame profile.   The lock-up feature within the body of the operator rather than a hook on the gear arm and lug on bracket reduces chance of the keeper missing the securing lug.   The lock-up feature within the body of the operator rather than the hook on the gear arm and lug on bracket means operator fits wider variety of window profiles.   The cover and handle can be removable for easy change of aesthetics, and the cover can snap on and off without tools.   Handle is screwed on using standard fastener which holds the handle tighter, with less slop, than a spring.   The anti-backdrive feature works in both directions. It prevents unauthorized entry in the locked position and also keeps the window from slamming shut in the open position, as for example due to wind.
 
Various embodiments of systems, devices, and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the claimed inventions. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the claimed inventions.
       

     Persons of ordinary skill in the relevant arts will recognize that the subject matter hereof may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the subject matter hereof may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the various embodiments can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted. 
     Although a dependent claim may refer in the claims to a specific combination with one or more other claims, other embodiments can also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of one or more features with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended. 
     Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein. 
     For purposes of interpreting the claims, it is expressly intended that the provisions of 35 U.S.C. § 112(f) are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.