Patent Publication Number: US-11391067-B2

Title: Electronically controlled padlock

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a padlock assembly including a body, a shackle movable relative to the body, a lock mechanism that can retain the shackle in a closed position and an electrically controlled actuator mechanism including a hand engageable portion that is external to the body for adjusting the condition of the lock mechanism. 
     2. Description of Related Art 
     Padlocks are used in a wide variety of applications including security applications such as lockers, gates and doors. A typical padlock will include a shackle and a body which houses a lock mechanism. A key will be inserted into a keyway of the lock mechanism to release the shackle allowing removal of the padlock from a hasp or other such portion of the locker, gate or door. One problem with typical padlocks is the keyway can be susceptible to vandalism by jamming foreign objects therein preventing normal operation of the padlock. Furthermore adjusting the keying of the padlock can be time consuming and not particularly cost effective if performed on the site of the locker, gate of door. 
     More recently padlocks have been designed to operate with an electronic keying system that interacts with an electrical lock mechanism within the body. Padlocks that use an electrical motor to adjust the lock mechanism acting directly on the retention of the shackle can use relatively large amounts of power to adjust the condition of the lock mechanism. This power usage impacts on their serviceable life between replacement of a power source. Whereas padlocks that utilise a smaller motor to act indirectly on the shackle will save on power, but will require some form of coupling that is often susceptible to manipulation from outside the body. 
     A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims. 
     SUMMARY OF THE INVENTION 
     According to this invention there is provided a padlock assembly including a body, a shackle movable relative to the body between an open position and a closed position, a lock mechanism that when in an active condition can retain the shackle in the closed position and in an inactive condition can allow the shackle to move to the open position, an actuator mechanism including a hand engageable portion that is external to the body and is manually movable relative to the body, the actuator mechanism being electrically controlled to adjust between and operable condition and an inoperable condition, a coupling mechanism acting between the lock mechanism and the actuator mechanism, a first influencing arrangement that facilitates retaining the lock mechanism in the active condition, wherein when the actuator is in the operable condition movement of the hand engageable portion causes the condition of the lock mechanism to adjust from the active condition to the inactive condition. 
     The manner in which the first influencing arrangement functions to retain the lock mechanism in the active condition may take any suitable form. In a preferred form the coupling includes a drive member which is impeded from moving from a first position by the first influencing arrangement, however the drive member is movable from the first position when the actuator is operable. The first influencing arrangement may include any means for influencing or biasing the drive member includes at least one first magnet associated with the drive member urging the drive member to remain in the first position. It is further preferred that the first influencing arrangement includes at least one second magnet that is fixed relative to the body. The first influencing arrangement may also include at least one third magnet that is located between the at least one second magnet and the at least one first magnet when the drive member is in the first position. Where the at least one third magnet is included the at least one second magnet and the at least one third magnet can combine to attract the at least one first magnet. Alternatively the same magnetic force may be achieved by a stronger at least one second magnet only. A further alternative could include the at least one second magnet and the at least one third magnet combine to repel the at least one first magnet. 
     It is preferred that the at least one first magnet, the at least one second magnet and at least one third magnet each include four magnets equally spaced about an actuator axis about which the actuator rotates. Furthermore it is preferred that each of the first magnets, the second magnets and the third magnets are aligned and spaced radially from the actuator axis. However the number and location of each of the magnets may vary from this preferred configuration and could include the at least one first magnet, the at least one second magnet and at least one third magnet each include two magnets equally spaced about an actuator axis about which the actuator rotates. Furthermore, each of the second magnets and third magnets are aligned and spaced radially from the actuator axis, while the first magnets are radially spaced from the actuator axis and misaligned with the second magnets and third magnets when the drive member is in the first position. 
     The padlock assembly preferably includes a second influencing arrangement that facilitates retaining the hand engageable portion in a preferred position relative to the drive member. The actuator may take any form and in one form it includes a shaft that is locatable within the body, a distal end of the shaft being configured to accommodate the drive member. The second influencing arrangement preferably includes at least one fourth magnet associated with the shaft of the actuator. It is further preferred that the drive member includes a head portion and the second influencing arrangement includes at least one fifth magnet associated with the head portion of the drive member. It is still further preferred that the at least one fourth magnet is repulsed by the at least one fifth magnet. Alternatively, the actuator includes a shaft that is locatable within the body, a distal end of the shaft being configured to interact with the drive member. The second influencing arrangement includes at least one fourth magnet associated with the shaft of the actuator. The second influencing arrangement includes at least one fifth magnet associated with the drive member. The at least one fourth magnet is attracted to the at least one fifth magnet. The at least one fourth magnet and at least one fifth magnet may each include two magnets spaced about the actuator axis, however this may vary. Alternatively, the at least one fourth magnet include two magnets spaced about the actuator axis and the at least one fifth magnet include four magnets spaced about the actuator axis. It is further preferred that each of the two fourth magnets and two fifth magnets are on opposed sides of the actuator axis. 
     The distal end of the shaft may be configured to capture the head of the drive member so as to be rotatable relative thereto. 
     The lock mechanism may take any suitable form, and in one preferred form includes a cam having at least one cam surface, and at least one detent to interact with the at least one cam surface, and the shackle is configured with at least one recess for receiving the at least one detent when the shackle is in the closed position and the lock mechanism is in the active condition. The number of recesses in the shackle, detents and cam surfaces may clearly vary. The lock mechanism may include a biasing arrangement for biasing on the cam. The preferred form of biasing arrangement includes a spring and an abutment plate, one end of the spring acting on the cam and another end of the spring acting on the abutment plate, whereby the abutment plate is fixed from rotating about the actuator axis to bias on the cam when the when the lock mechanism is in the inactive condition. Clearly other forms of biasing arrangement are possible. 
     The coupling may take any suitable form and in one form includes a driven member that has a distal side configured to drivingly engage with the cam so that rotation of the driven member causes rotation of the cam against the action of the spring. It is further preferred that the driven member includes a proximal side configured to drivingly engage with the drive member so that rotation of the drive member causes rotation of the driven member. Alternatively, the drive member includes a distal side configured to drivingly engage with the cam so that rotation of the driven member causes rotation of the cam against the action of the spring. 
     The actuator preferably includes an interlocking mechanism that is electrically controlled so that the actuator is adjustable between an operable condition and an inoperable condition. The interlocking arrangement may take any suitable form and in a preferred form includes a catch movable between an extended position and a retracted position with the actuator adopting the operable condition when the catch is in the extended position. It is preferred that the interlocking arrangement includes a biasing member for biasing the catch towards the extended position and a selectively operable blocking mechanism for blocking the catch from moving towards the retracted position. It is further preferred that the selectively operable blocking mechanism includes a blocking member and an electrical adjuster which adjusts the orientation of the blocking member relative to the catch between a blocked position and an un-blocked position. Alternatively, the interlocking arrangement includes an electrical adjuster that is operable to move a movable member between an extended position and a retracted position whereby the actuator adopts the operable condition when the movable member is in the extended position and the movable member interacts with a recess in the coupling when it is in the extended position. It is further preferred that the padlock assembly include an electronic authorisation arrangement for receiving and processing a signal from an authorisation key, and controlling operation of the electrical adjuster on receipt of an authorised key. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It will be convenient to hereinafter describe a preferred embodiment of the padlock according to the invention. The particularity of the illustrations and the associated detailed description is merely illustrative of one embodiment of the invention and is not intended to be limiting on the scope of the claims. 
         FIG. 1  illustrates an isometric view of a preferred embodiment of the padlock. 
         FIG. 2  is an exploded isometric view of the padlock from  FIG. 1  from one perspective. 
         FIG. 3  is an exploded isometric view of the padlock from  FIG. 1  from an opposite perspective. 
         FIG. 4  is a cross-sectional view of the padlock from  FIG. 1  with the lock mechanism in an active condition, and the actuator in an operable condition. 
         FIG. 4A  is an exploded view of area A from  FIG. 4 . 
         FIG. 5  is the cross-sectional view of the lock assembly shown in  FIG. 4  with the lock mechanism in an inactive condition, the shackle in an open position. 
         FIG. 5B  is a detailed view of area B from  FIG. 5 . 
         FIG. 6  is a side elevation view of the drive member and actuator, with the actuator being in an inactive condition. 
         FIG. 7  is a side elevation view of the actuator and drive member with the actuator rotating relative to the drive member from the position illustrated in  FIG. 6 . 
         FIG. 8  is a cross-sectional view through the actuator and drive member through XIII of  FIG. 7 . 
         FIG. 8C  is a detailed view of the area C from  FIG. 8 . 
         FIG. 9  is a cross-sectional view through IX from  FIG. 8 . 
         FIG. 9D  is a detailed view of the area D from  FIG. 9 . 
         FIG. 10  is a side elevation view of the actuator and drive member with the actuator in the operable condition and the drive member rotated from the position illustrated in  FIG. 6 . 
         FIG. 11  is a cross-sectional view through XI from  FIG. 10 . 
         FIG. 11E  is a detailed view of area E from  FIG. 11 . 
         FIG. 12  is a cross-sectional view through XII from  FIG. 11 . 
         FIG. 12F  is a detailed view of area F from  FIG. 12 . 
         FIG. 13  is an exploded isometric view of an alternate embodiment of the padlock from  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     Referring to  FIG. 1  there is shown a preferred embodiment of a padlock assembly  1  including a body  2  and shackle  3 . The shackle  3  is movable relative to the body  2  between a closed position as illustrated in  FIG. 1  and an open position (see  FIG. 5 ) so as to allow for the padlock to be attached to a hasp (not shown) or other such facility.  FIG. 1  also illustrates a hand engageable portion  4  in the form of a knob forming part of an actuator mechanism  5 , the hand engageable portion  4  can be rotated about an actuator axis X-X in order that a shackle  3  can be released to move to the open position. However in order to provide the padlock assembly  1  with some form of security the actuator  5  is adjustable between an operable condition and an inoperable condition in a manner that will be described in greater detail by reference to latter illustrations. However it is preferred that the padlock assembly  1 , and in particular the actuator  5  house some form of electronic authorisation means  6  such as a microprocessor, control electronics and antennae for interacting with some form of proximity security card  7  or other RFID security device to limit operation of the actuator to authorised users only. 
     Referring now to  FIG. 2  which illustrates a substantially U-shaped shackle  3  with a relatively long leg  8  and a relatively short leg  9  spaced apart by a curved portion  10 . Both the long leg  8  and short leg  9  each include a relatively deep recess  12 ,  11  formed therein at a position spaced from the curved portion  10 . The long leg  8  also includes a planar surface  13  adjacent the deep recess  12  extending towards a free end of the long leg  8  and terminating in a relatively shallow annular recess  14 . A compression spring  15  is also provided to act in between the long leg  8  of the shackle  3  and the body  2  for urging the shackle  3  towards the open position. The body  2  includes a pair of spaced apertures  16 ,  17  with the lower of the two apertures  17  configured to accommodate the shackle spring  15  and the long leg  8 , whilst the upper aperture  16  is configured to accommodate a portion of the short leg  9  when the shackle  3  is in a closed position (see  FIG. 4 ). 
     Referring again to  FIG. 2  there is shown two ball detents  18 ,  19  which form part of a lock mechanism  31 , and are configured to interact with the recesses  12 ,  11  in the long leg  8  and short leg  9  when the shackle  3  is in the closed position. The balls  18 ,  19  are inserted into the body  2  through an aperture (not shown) in a lower wall (not shown) in the body  2 . The aperture in the lower wall is then permanently closed with a cap  20  in a manner that will be appreciated by those skilled in the art. 
     Referring again to  FIG. 2  there is shown a cam member  21  having a pair of cam surfaces  22 ,  23  formed on opposed sides of the cam member  21 . Each cam surface  22 ,  23  is configured in order to control radial movement of each respective ball detent  18 ,  19  relative to the actuator axis X-X on rotation of the cam  21  about the actuator axis X-X. Whilst each cam surface  22 ,  23  illustrated in  FIG. 2  is in the shape of combined crescent shapes, the cam surface  22 ,  23  may have different shape to that as illustrated in  FIG. 2  and yet still achieve the same function. 
     The lock mechanism  31  illustrated in  FIG. 2  also includes a biasing arrangement  24  for biasing the cam  21  to urge the lock mechanism  31  to adopt an active condition. The biasing arrangement  24  includes a torsion spring  25  having an inner end  26  that locates in a groove  27  (see  FIG. 3 ) formed in a proximal surface of the cam  21 . An outer end  28  of the torsion spring  25  is formed as a hook which locates about a lug  29  on an abutment plate  30 . The abutment plate  30  is fixed from movement about the actuator axis X-X by snugly locating within a figure of eight bore  40  (see  FIG. 3 ) in the body  2 . Tension can be applied to the torsion spring  25  when the cam  22  is rotated causing the lock mechanism  31  to adjust from the active condition. 
     Referring again to  FIG. 2  there is shown a coupling mechanism  32  acting between the lock mechanism  31  and the actuator mechanism  5 . The coupling mechanism includes a drive member  33  and a driven member  34  whereby the drive member  33  is attached to the driven member  34  by a pair of screws  35 . The distal surface of the drive member  33 , and proximal surface of the driven member  34  (partially obscured in  FIG. 3 ) are configured to drivingly mate with one another so as to facilitate transfer of torque through the drive member  33  to the driven member  34  in addition to the screw fastener  35  attachment. Whilst the preferred configuration involves some form of tongue and groove arrangement, other configurations to drivingly mate are clearly possible. The coupling mechanism  32  also includes a coupling housing assembly, which in the embodiment illustrated includes a base  36  and a cap  37 . The base illustrated is in the form of a relatively standard cylinder lock housing with a bible portion  38  extending from a barrel portion  39 . The bible portion  38  is located within the cap  37 , and the whole coupling housing inserted in a figure of eight bore  40  (see  FIG. 3 ) in the body  2 . A screw  41  is then used to fasten the coupling housing, or more specifically the cap  37  to the body  2  so as to fasten the housing within the body  2 . Clearly the shape of the coupling housing may vary from that as illustrated in  FIG. 2 . 
     Referring again to  FIG. 2  which shows a distal surface of the driven member  34  configured to drivingly interact with a proximal surface of the cam  21  (see  FIG. 3 ). Specifically the distal surface of the driven member includes a pair of radially spaced wedge portions  42  which locate on opposed sides of a vertical flange  65 . When assembled the flange  65  extends through the center of the torsion spring  25  and a complementary shaped aperture  43  (see  FIG. 3 ) formed in the abutment plate  30 . The respective shapes of the aperture  43  and the flange  65  limits movement of the cam to no more than  90 . Clearly however the shape of the aperture  43 , flange  65  and the wedges  42  may vary from that as illustrated in  FIGS. 2 and 3 . 
     Referring again to  FIG. 2  which shows the actuator including a shaft  44  extending from the hand engageable portion  4 . The shaft  44  is shaped to locate within the barrel  39 , and to rotate there within on manual rotation of the hand engageable portion  4  by an authorised user. The actuator  5  also includes a blocking mechanism  45  having an electrical adjuster  46  with a blocking member  47  which is located within a recess formed in an underside of the shaft  44 . The electrical adjuster  46  and blocking member  47  form part of an interlocking mechanism, the operation of which is controlled by the electronic authorisation means  6 . The interlocking mechanism also includes a catch  48 , and a cover  49 , both of which are biased towards an extended position and are locatable within a groove  50  formed in an upper surface of the shaft  44 .  FIG. 2  illustrates a number of compression springs  52 ,  51  for independently biasing the catch and cover  48  towards the extended position. The catch  48  is configured to interact with the drive member  33  in a manner which will be described in greater detail with reference to latter illustrations. Alternatively, the drive member and driven member may be replaced by a single drive member  133  as illustrated in  FIG. 13 . 
     Referring again to  FIG. 2  which shows a radial extending slot  53  formed in a distal end of the shaft  44 . The radial slot is configured to accommodate a neck portion  54  (see  FIG. 3 ) of the drive member  33  which extends between a head portion  55  and a body portion  56  of the drive member  33 . This configuration allows for rotation of the drive member  33  relative to the actuator  5 , whilst preventing axial movement of the actuator  5  relative to the drive member  33  when the padlock assembly  1  is assembled. Alternatively, as illustrated in  FIG. 13  the distal end of the shaft  44  may be attached to the single drive member  133  by way of a screw  180 . This alternate arrangement still allows for rotation of the single drive member  133  relative to the actuator  5 . 
     It is an aspect of the invention that the padlock assembly include a first influencing arrangement that facilitates retaining the lock mechanism  31  in the active condition. This may be achieved in any suitable arrangement, and in the embodiment illustrated in  FIG. 3 , the first influencing arrangement preferably includes four first magnets  57  with the body  56  of the drive member  33 , four second magnets  58  fixed to the body  2 , and four third magnets  59  fixed to the barrel. The number and location of the magnets  57 ,  58 ,  59  may vary from that as illustrated in  FIGS. 2 and 3 , and in the broadest embodiment of the invention the first influencing arrangement may include only one first magnet  57 , one second magnet  58  and only one third magnet  59 . While in the alternate embodiment illustrated in  FIG. 13  the first influencing arrangement includes two first magnets  157 , two second magnets  158  and two third magnets  159 . 
     The preferred arrangement illustrated in  FIGS. 2 and 3  the magnetic force produced by the second magnets  58  and the third magnets  59  combine to attract the magnetic force produced by the first magnets  57 . While in the alternate embodiment illustrated in  FIG. 13  the magnetic force produced by the second magnets  158  and third magnets  159  combine to repel the first magnets  157 . Both of these embodiments facilitate retaining the drive member  33 ,  133  absent any other external forces, in a first position relative to the body  2 ,  102 . Furthermore, provided that the orientation of the cam  21 ,  121  relative to the drive member  33 ,  133  is as shown in for example  FIG. 4 , it will result in the influencing arrangement facilitate retaining the lock mechanism  31  in the active condition. 
     Referring again to  FIG. 3  which illustrates a second influencing arrangement acting between the actuator  5  and the drive member  33 . Once the first influencing arrangement has oriented the drive member  33  to its first position, the second influencing arrangement, in the absence of external forces to the contrary, facilitates adjusting the hand engageable portion  4  towards a preferred position relative to the drive member  33 . The second influencing arrangement illustrated in  FIG. 3  includes a pair of fourth magnets  60  (see also  FIG. 2 ) associated with the shaft  44 , and a pair of fifth magnets  61  associated with the head portion  55  of the drive member  33 . The magnetic forces of the fourth magnets  60  and fifth magnets  61  are repulsive so as to rotate hand engageable portion  4  relative to the drive member  33 . Clearly the number and orientation of the fourth magnets  60  and fifth magnets  61  may vary from that as illustrated in  FIG. 2 , and in the broadest embodiment includes only one fourth magnet  60  and one fifth magnet  61 . Furthermore the magnetic forces of the fourth magnets  60  and fifth magnets  61  may be attractive, however their relative positions would need to change. The alternate embodiment illustrated in  FIG. 13  includes two fourth magnets  160  on the distal end of the shaft  144 , and four fifth magnets  161  for location in recesses  181  in the single drive member  133 . In this alternate embodiment the magnetic forces of the fourth magnets  160  and fifth magnets  161  are attractive. 
     Referring now to  FIG. 4  which shows the shackle  3  in a closed position, and the lock mechanism  31  in an active condition. When the lock mechanism  31  is in this active condition the rotational position of the cam  21  relative to the ball detents  18 ,  19  is one such that the cam surfaces  22 ,  23  on the cam  21  are urging the ball detents  18 ,  19  to move radially relative to the actuator axis, to locate within the larger recesses  12 ,  11  formed in the long and short legs  8 ,  9  of the shackle  3 . While the cam  21  remains in the position illustrated in  FIG. 4 , movement of the shackle  3  relative to the body  2  is prevented. In order to allow the shackle  3  to move to an open position, the lock mechanism  31  must be adjusted to an inactive condition. 
       FIG. 4  illustrates the actuator  5  in an operable condition, and in particular  FIG. 4A  illustrates the catch  48  in an extended position whereby it rotationally overlaps with a flange  62  formed on the drive member  33 . With the catch  48  in this extended position, rotation of the hand engageable portion  4  from the position illustrated in  FIG. 4 , to the position illustrated in  FIG. 5  will result in rotation of the cam  21  so as to allow the lock mechanism  31  to adopt an inactive condition. This allows the ball detent  18 ,  19  to retract radially inwardly from the recesses  11 ,  12  formed in the long leg and short leg  8 ,  9  of the shackle  3 . The compression spring  15  acting on the shackle  3  then causes the shackle  3  to move relative to the body  2  to adopt and open position. Once the user has ceased applying a rotational force to the hand engageable portion  4 , the drive member  33  and actuator  5  will return to the first position and preferred position respectively under the influence of the first influencing arrangement and second influencing arrangements. However the cam member  21  will be retained in the position as illustrated in  FIG. 5 , notwithstanding biasing force produced by the torsion spring  25  acting on the cam  21  urging the lock mechanism  31  to return to the active condition. The cam  21  will be prevented from rotating by the ball detent  19  acting between the long leg  8  of the shackle  3  and the cam  21 , until such time as the shackle  3  is returned to the closed position. Once the shackle  3  is returned to the closed position, the cam  21  can rotate under the influence of the torsion spring  25  to return to the position as illustrated in  FIG. 4 . 
     The adjustment of the actuator  5  between an operable condition and inoperable condition will now be described in greater detail with reference to  FIGS. 6 to 12F .  FIG. 6  illustrates the drive member  33  in a first position, and the hand engageable portion  4  of the actuator  5  in a preferred position relative to the drive member  33 , each under the influence of the first influencing arrangement and second influencing arrangements respectively.  FIG. 6  also illustrates the cover  49  of the interlocking arrangement in an extended position under the influence of its spring  51 . In contrast  FIG. 7  illustrates the hand engageable portion  4  having been rotated from its preferred position. While the actuator  5  is in the inoperable condition, as illustrated in  FIGS. 7 to 9D , rotation of the hand engageable portion  4  will result in a distal end of the cover  49  gliding over the flange  62  of the drive member  33  whilst retracting into the end of the slot. This will permit relative rotation of the hand engageable portion  4  relative to the drive member  33 . Referring now to  FIG. 8  we can appreciate that retraction of the cover  49 , also results in retraction of the catch  48  away from the extended position, and a lower leg  63  of the catch  48  is free to move relative to the blocking member  47  which can be more clearly appreciated from  FIG. 8C . Furthermore it can be appreciated from  FIGS. 9 and 9D  that the blocking member  47  includes a shoulder  64  that is spaced from the lower leg  63  of the catch  48  when the actuator  5  is in the inoperable condition. 
     In contrast  FIGS. 10 to 12F  illustrate the actuator  5  in the operable condition whereby rotation of the hand engageable portion  4  from the position as illustrated in  FIG. 6  to the position as illustrated in  FIG. 10  results in retraction of the cover  49  but not the catch  48  of the interlocking arrangement.  FIG. 10  illustrates the distal end of the catch  48  remaining in the extended position overlapping with the flange  62  on the drive member  33 . It can be appreciated from  FIG. 11  that the lower leg  63  of the catch  48  is retained in a forward position relative to the position illustrated in  FIG. 8 , and can be more clearly appreciated from  FIG. 11E  that the shoulder  64  on the blocking member  47  is positioned behind the lower leg  63  on the catch  48 . Referring now to  FIG. 12  which illustrates the blocking member  47  having been rotated in an anti-clockwise direction from the position as illustrated in  FIG. 9 , and it can be appreciated more clearly from  FIG. 12F  that the shoulder  64  is now located behind the lower leg  63  of the catch  47 . 
     The alternate embodiment illustrated in  FIG. 13  includes an interlocking arrangement including a pin  182  which is movable relative to the shaft  144  on operation of the electrical adjuster  146 . The pin is movable from a retracted position whereby it is retracted within the shaft  144 , to an extended position whereby it extends between the shaft  144  to locate within one of four recesses  183  formed in the single drive member  133 . 
     It ought to be appreciated from the foregoing that the padlock assembly utilising the first influencing arrangement to facilitate retaining the lock mechanism  31  in the active condition will be less susceptible to unauthorised manipulation from outside the body  2 . 
     Various alterations and/or additions may be introduced into the padlock assembly as hereinbefore described without departing from the spirit or ambit of the invention. 
     Future patent applications may be filed in Australia or overseas on the basis of or claiming priority from the present application. It is to be understood that the following provisional claims are provided by way of example only, and are not intended to limit the scope of what may be claimed in any such future application. Features may be added to or omitted from the provisional claims at a later date so as to further define or re-define the invention.