Patent Publication Number: US-2004040821-A1

Title: Drop safe having a gas spring control system

Description:
CROSS REFERENCE TO RELATED APPLICATION(S)  
     [0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Serial No. 60/408,409, filed on Sep. 4, 2002. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] The present invention relates generally to a drop safe and more particularly to a drop safe that includes a gas spring having a cam bearing that moves along a cam surface or cam profile for a controlled opening and closing of a drop safe door, chassis or other pivotal component.  
       BACKGROUND  
       [0003] A drop safe is a device for receiving and temporarily storing currency or other valuables. Drop safes are typically used in stores such as groceries stores, convenient stores or gas stations. In these stores, it is common to prevent or discourage theft by frequently transferring currency from relatively unsecure devices, such as cash registers or point-of-sale terminals, to relatively secure devices, such as drop safes.  
       [0004] Since drop safes are secure enclosures designed to be “theft-proof”, drop safe doors are often relatively heavy. As a result, when an operator rotates the door towards a closed position or towards an opened position, the weight of the door causes the door to have a tendency to, respectively, “slam” itself shut when the door is almost closed or to swing open very quickly when the door is opened. Thus, producing an undesirable risk of an injury to the operator. For example, the weight of the door may cause the door to close so quickly as to not provide the operator with enough time to remove the operator&#39;s hand or fingers from between the door and the door jam during the closing of the door. The “self-closing” nature of the door may similarly cause an injury to the operator&#39;s hand or fingers. In addition, the weight the door is cumbersome for some operators to manipulate.  
       [0005] One drop safe of the prior art includes a gas spring attached to a lever that is, in turn, attached to a drop safe door. The gas spring counteracts the weight of the door during opening and closing of the door. See, for example, U.S. Pat. No. 5,695,038.  
       SUMMARY  
       [0006] In one embodiment, the present invention includes a drop safe, having a pivoting component and a cam attached to an interior surface of the drop safe, wherein the cam has a cam surface. A gas spring moves along the cam surface by means of a cam bearing, which is at one end of the gas spring, such that the cam bearing moves along the cam surface. A link is attached to the gas spring and to the pivoting component, such that as the cam bearing moves along the cam surface, the link applies a force to the pivoting component. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0007] These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:  
     [0008]FIG. 1 is a side cross-sectional view of a drop safe according to the present invention, wherein a drop safe door is in a closed position;  
     [0009]FIG. 2 is a side cross-sectional view of the drop safe of FIG. 1, wherein a cam bearing is held in a neutral point detent, thus holding the drop safe door in a partially opened position;  
     [0010]FIG. 3 is a side cross-sectional view of the drop safe of FIG. 1, wherein the cam bearing is held in a fully open detent, thus holding the drop safe door in a fully opened position;  
     [0011]FIG. 4 is an enlarged side cross-sectional view of the neutral point detent taken from detail  4  of FIG. 1;  
     [0012]FIG. 5 is an enlarged side cross-sectional view of the fully open detent taken from detail  5  of FIG. 1;  
     [0013]FIG. 6 is a partial side cross-sectional view of the drop safe of FIG. 1, wherein a initial force bracket has been removed to expose a recessed area in a distal end of a cam slot;  
     [0014]FIG. 7 is a perspective cut away view of an initial force bracket of the drop safe of FIG. 1.  
     [0015]FIG. 8 is a perspective cut away view of an embodiment of the invention wherein the gas spring is attached to a chassis, the chassis being shown in a closed position;  
     [0016]FIG. 9 is a perspective cut away view of the chassis of FIG. 8, wherein the chassis is shown in an opened position; and  
     [0017]FIG. 10 is a perspective cut away view of the chassis of FIG. 8. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION  
     [0018] As shown in FIGS.  1 - 7 , an embodiment of the present invention is directed to a drop safe, wherein the drop safe includes a gas spring having a cam bearing that moves along a cam surface (also referred to as a cam profile) for a controlled opening and closing of a drop safe door, and wherein the cam surface has a neutral point detent for holding the drop safe door in a partially opened position and a fully open detent for holding the drop safe door in a fully opened position.  
     [0019]FIG. 1 shows a drop safe  10  according to the present invention, wherein a drop safe door  12  is shown in a closed position. In the depicted embodiment, a cam  14  is attached to an interior surface of the drop safe  10 , such as by screw fastening, riveting or welding, among other attachment means. For example, in one embodiment, the cam  14  is a plate that is screw fastened to a mounting bracket  20  on the interior surface of the drop safe  10 . The cam  14  may comprise any one of a variety of rigid materials, such as a metal material, for example steel sheet metal, among others. The cam  14  comprises a cam surface or cam profile  16  for engagement with a gas spring  18 . For example, in one embodiment, the cam  14  has a slot  22  that defines the cam surface  16 .  
     [0020] As depicted in FIG. 1, the gas spring  18  has a proximal end  22  and a distal end  24  (for the purposes of this application proximal and distal will be defined by reference to the elements as they appear to an operator looking inside the drop safe  10  when the drop safe  10  is in an opened door position, as in the depiction of FIG. 3). A suitable gas spring  18  for use in the drop safe  10  of the present invention is commercially available from Guden-Hardware for Industry, of Ronkonkoma, N.Y., for example a 120 pound gas spring. In the depicted embodiment, the distal end  24  of the gas spring  18  is attached to the interior surface of the drop safe  10  through a pivot bracket  30 . The pivot bracket  30  allows for a pivotable movement of the gas spring  18 . A cam bearing  26  is attached to the proximal end  22  of the gas spring  18  for slidable or rotational movement along the cam surface  16 . For example, in one embodiment (as best shown in FIG. 7) the proximal end  22  of the gas spring  18  is attached to one end of a yoke bracket  28 , and the cam bearing  26  is attached to an opposite end of the yoke bracket  28 . The cam bearing  26  may be attached to the yoke bracket  28  by a pin to allow for rotational movement of the cam bearing  26 , such that the cam bearing  26  may slidably or rotatably move about the cam surface  16 . The cam bearing  26  may comprise any one of a variety of rigid materials, such as a metal material, for example steel, among others.  
     [0021] The gas spring  18  may be connected to the drop safe door  12  by a link  32 . For example, in the depicted embodiment, one end of the link  32  is pivotably connected to the yoke bracket  28  and an opposite end of the bracket is pivotably connected to a mounting bracket  34  that is attached to the drop safe door  12 .  
     [0022] In one embodiment, an initial force bracket  36  is attached to the cam  14 , such that the cam bearing  26  moves along the initial force bracket  36  and the cam surface  16 . In this embodiment, a proximal end  38  of the initial force bracket  36  and a distal end  40  of the cam surface  16  combine to form a neutral point detent  42  (as best shown in detail  4  of FIG. 4). The neutral point detent  42  temporarily hinders the movement of the gas spring  18  to hold the drop safe door  12  in a partially opened position (as shown in FIG. 2). In the depicted embodiment, the neutral point detent  42  is a v-shaped gap between the proximal end  36  of the initial force bracket  36  and the distal end  40  of the cam surface  16 . However, in other embodiments, the neutral point detent  42  may comprise other shapes, such as semi-rectangular, semi-circular or semi-ovular, among others. In addition, in other embodiments, the neutral point detent  42  may be formed as a groove in either the initial force bracket  36  or the cam surface  16 . Also, in alternative embodiments, the neutral point detent  42  may be formed as a protrusion from the initial force bracket  36  or the cam surface  16 , rather than an indention in the initial force bracket  36  or the cam surface  16  or a gap between the initial force bracket  36  and the cam surface  16 .  
     [0023] A proximal end  44  of the cam surface  16  comprises a fully open detent  46  (as best shown in detail  5  of FIG. 5). In the depicted embodiment, the fully open detent  46  is a recessed groove in the proximal end  44  of the cam surface  16 . The recessed groove may comprise any suitable shape, such as v-shaped, semi-rectangular, semi-circular or semi-ovular, among others. The fully open detent  46  temporarily hinders the movement of the gas spring  18  to hold the drop safe door  12  in a fully opened position (as shown in FIG. 3). Although not shown, a distal end of the cam surface  16  or a distal portion of the initial force bracket  36  may contain a fully closed detent, such as a recessed groove, to temporarily hinder the movement of the gas spring  18  to hold the drop safe door  12  in a fully closed position.  
     [0024] In the depicted embodiment, the combination of the initial force bracket  36  and the cam surface  16  forms a curve that initially bends upward and then bends downward. In one embodiment, the apex of the curve is at the neutral point detent  42 . However, in other embodiments, the apex of the curve may be in the initial force bracket  36  portion of the curve or in the cam surface  16  portion of the curve. In one embodiment, the shape of the curve can be determined based on a mathematical formula that takes into account the length of the link  32 , the x-y coordinates of the center of gravity of the door  12 , the weight of the door  12 , the rotation angle of the door  12  with respect to the vertical/closed door position at every point along the curve, the force of the gas spring  18  at full strength, the minimum compression length of the gas spring  18 , the maximum extension length of the gas spring  18 , the x-y coordinates of the pivot bracket  30 , the x-y coordinates of the door mounting bracket  34 , the angle of the door fully opened position with respect to a vertical plane and the angle to the door fully closed position with respect to the vertical plane.  
     [0025] As one of ordinary skill in the art will understand, a gas spring continually applies a force towards extension of the gas spring. As a result, when a deadbolt (not shown), or another similar locking means that is secured against the drop safe door  12 , is moved to an unlocked position, typically by activating a key cylinder or a combination tumbler, the gas spring  18  applies an extension force on the initial force bracket  36  causing the cam bearing  26  to move along the initial force bracket  36 , which, in turn, causes the link  32  to apply a force to the door  12  to open the door  12 , such as by rotating the door  12  about one or more hinges  48 . Thus, upon unlocking the door  12 , the gas spring  18  automatically applies a force on the door  12  to open the door  12 .  
     [0026] However, in the door closed position, the center of gravity of the door  12  causes the weight of the door  12  to resist opening. Therefore, the gas spring  18  must be chosen such that it is strong enough to overcome the weight of the door  12 . By choosing an appropriate strength of gas spring  18 , the counteracting forces of the gas spring  18  and the weight of the door  12 , produces a relatively slow movement of the door  12  as the door  12  moves from the closed position to the neutral point detent  42 , such that the likelihood of operator injury is reduced.  
     [0027] As shown in FIG. 2, upon unlocking the door  12 , the gas spring  18  extends and thus the cam bearing  26  moves along the initial force bracket  36  until the cam bearing  26  reaches the neutral point detent  42 . At the neutral point detent  42 , the cam bearing  26  is temporarily held in place, such that the drop safe door  12  is temporarily held in the partially opened position.  
     [0028] In depicted embodiment, when the cam bearing  26  is in the neutral point detent  42  such that the drop safe door  12  is held in the partially opened position, the door  12  is opened to an angle α, with respect to a vertical/closed door position, that is in a range of approximately 15° to approximately 35°. In one embodiment, the angle α of the partially opened position is approximately 25°.  
     [0029] Once the cam bearing  26  is in the neutral point detent  42 , the cam bearing  26 , and thus the door  12 , is held in position until an operator applies an external force to the door  12  in either the door closing or the door opening direction. When the operator applies an appropriate external force to the door  12  in the door opening direction, i.e. a force that is sufficient to compress the gas spring  18 , the gas spring  18  disengages from the neutral point detent  42 , such that the cam bearing  26  may move to a position proximal to the neutral point detent  42 . The operator may then continue to apply an external force to the door  12  in the door opening direction until the cam bearing  26  reaches the fully open detent  46 . At the fully open detent  46  the cam bearing  26 , and thus the door  12 , is held in place. In one embodiment, when the cam bearing  26  is positioned at any point between the neutral point detent  42  and the fully open detent  46 , the gas spring  18  produces a force on the door  12  to counteract the weight of the door  12  to prevent the door  12  from rapidly opening and possibly injuring the operator.  
     [0030] In the depicted embodiment of FIG. 3, when the cam bearing  26  is in the fully open detent  46 , such that the drop safe door  12  is held in the fully opened position, the door  12  is opened to an angle β, with respect to a vertical/closed door position, that is in a range of approximately 85° to approximately 125°. For instance, in one example, the angle β of the fully opened position is approximately 105°.  
     [0031] In one embodiment, when the door  12  is at any position between the partially opened and the fully opened positions, i.e. anywhere between the angle α and the angle β, and the door  12  is free from external forces, the cam bearing  26  automatically moves along the cam surface  16 , due to the extension force of the gas spring  18 , until the cam bearing  26  engages the neutral point detent  42 . This embodiment may be produced by choosing a gas spring  18  and a center of gravity of the door, wherein the strength of the gas spring  18  is great enough to overcome the weight of the door  12  at every point between the neutral point detent  42  and the fully open detent  46  of the cam surface  16 .  
     [0032] Once the cam bearing  26  is in the fully open detent  46 , the cam bearing  26 , and thus the door  12 , is held in position until the operator applies an appropriate external force to the door  12  in the door closing direction, i.e. a force that is sufficient to compress the gas spring  18  to disengage the gas spring  18  from the fully open detent  46 , such that the cam bearing  26  may move to a position distal to the fully open detent  46 . In one embodiment, once the cam bearing  26  is in a position distal to the fully open detent  46 , and the door  12  is free from external forces, the cam bearing  26  automatically moves along the cam surface  16 , due to the extension force of the gas spring  18 , until the cam bearing  26  engages the neutral point detent  42 .  
     [0033] As described above, once the cam bearing  26  is in the neutral point detent  42 , the cam bearing  26 , and thus the door  12 , is held in position until an operator applies an external force to the door  12  in either the door closing or the door opening direction. When the operator applies an appropriate external force to the door  12  in the door closing direction, i.e. a force that is sufficient to compress the gas spring  18 , the gas spring  18  disengages from the neutral point detent  42 , such that the cam bearing  26  may move to a position distal to the neutral point detent  42 . With the cam bearing  26  positioned distal to the neutral point detent  42 , the operator may continue to apply an appropriate external force to the door  12  to move the cam bearing  26  along the initial force bracket  36  until the door  12  reaches the closed position and the door  12  is locked by actuation of a deadbolt or another similar locking means that secures the door  12  in the closed door position.  
     [0034] In one embodiment, when the cam bearing  26  is positioned at any position proximal to the closed door position and distal to the neutral point detent  42 , the gas spring  18  automatically forces the cam bearing  26  towards the neutral point detent  42 . Thus, an explicit force is required by the operator in order to close the door  12 . Consequently, the risk of injury caused by the previously described “self-closing” door of the prior art is reduced.  
     [0035] In one embodiment, the initial force bracket  36  is rotatably mounted to the cam  14  (as discussed below), which allows the upward bend of the curve defined by the initial force bracket  36  to be increased (i.e. by a counter-clockwise movement) or decreased i.e. by a clockwise movement) as desired. Increasing or decreasing the upward bend of the curve defined by the initial force bracket  36 , respectively, increases or decreases the force that the gas spring  18  exerts on the door  12  as the cam bearing  26  moves along the initial force bracket  36 . This adjustment is desirable because over time the gas spring  18  loses pressure and therefore produces a less forceful extension force. This is due to the gas that is internally disposed within the gas spring  18 . The internally disposed gas supplies pressure to the gas spring  18  to allow the gas spring  18  to continually exert an extension force. Since the seals that contain the internally disposed gas are not perfect seals, over time some of the gas seeps through the seals and the gas spring  18  consequently loses some of its internal pressure. When this occurs, the initial force bracket  36  can be rotated upward, such that the upward bend of the curve defined by the initial force bracket  36  is increased. This increases the force that is transferred from the gas spring  18  to the door  12 . Thus, rotatably mounting the initial force bracket  36  to the cam  14  increases the useful life of the gas spring  18 .  
     [0036] In one embodiment, the door  12  is approximately 45 pounds (lbs.) and the gas spring  18  is a 120 pound gas spring. In this embodiment, the counterforces of the gas spring  18  and the weight of the door  12  produces an approximately constant force on the door  12  in the range of 5 to 10 lbs. This force can easily be overcome by the operator and makes an otherwise heavy door easy to manipulate. It should be noted that in some embodiments there are points in the movement of the cam bearing  26  along either the initial force bracket  36  or the cam surface  16  were the force of the gas spring  18  and the weight of the door are not counteracting, i.e., they each exert a force on the door  12  in either the door closing direction or the door opening direction.  
     [0037]FIGS. 6 and 7 show one method of rotatably mounting the initial force bracket  36  to the cam  14 . A mounting bracket  50  is attached to the cam  14  by at least one screw fastener  52 , or another appropriate fastening means. The initial force bracket  36 , in turn, is similarly attached to the mounting bracket  50  by at least one screw fastener  53 , or another appropriate fastening means. The mounting bracket  50  comprises openings for receiving the screw fasteners  52 , wherein at least one of the openings is a slotted opening  54 . The at least one slotted opening  54  allows the mounting bracket  50  to be rotated upwardly or downwardly, to correspondingly adjust the initial force bracket  36  upwardly or downwardly. Although not shown, in another embodiment the initial force bracket  36  is mounted directly to the cam  14 .  
     [0038] As previously discussed and as shown in FIG. 4, in one embodiment, the proximal end  38  of the initial force bracket  36  and the distal end  40  of the cam surface  16  combine to form a neutral point detent  42 . In one embodiment, the corresponding facing surfaces  38 F and  40 F, respectively, of the initial force bracket  36  and the cam surface  16  (as shown in FIG. 4) are concentric about the same center point  55  (as shown in FIGS.  1 - 3  and  6 - 7 ). As such, when the initial force bracket  36  is rotated, a spacing between the facing surfaces  38 F and  40 F of the initial force bracket  36  and the cam surface  16 , respectively, remains unchanged.  
     [0039] In one embodiment, a distal portion of the cam surface  16  has a recessed area  56 . For example, as shown in FIG. 6, a distal portion of the slot  22  in the cam  14  comprises the recessed area  56 . In such an embodiment, the initial force bracket  36  may be attached to the cam  14 , such that a portion of the initial force bracket overlaps at least a portion of the recessed area  56 . The addition of the recessed area  56  facilitates the removal and/or replacement of the gas spring  18 . For example, the cam bearing  26  may be positioned such that the cam bearing  26  does not contact the initial force bracket  36 , such as by positioning the cam bearing  26  in the fully open detent  46 . The initial force bracket  36  can then be removed from the cam  14 . With the initial force bracket  36  removed from the cam  14 , the cam bearing  26  may be moved to a position within the recessed area  56 . At least a portion of the recessed area  56  should be recessed to an extent that when the cam bearing  26  is disposed therein, the gas spring  18  is allowed to fully extend. With the gas spring  18  in the fully extended position, the gas spring  18  can be easily removed from the drop safe  10  without the need for specialized tools, for example, by simply disengaging the proximal end  22  of the gas spring  18  from the yoke bracket  28  and disengaging the distal end  24  of the gas spring  18  from the pivot bracket  30 .  
     [0040] Although the preceding description has described the cam surface  16  as having a initial force bracket  36  attached thereto, in one embodiment the cam surface  16  does not contain an initial force bracket  36 . In such an embodiment, each of the detents (the fully closed detent, the neutral point detent  42  and the fully open detent  46 ) may be formed as recesses in or protrusions from the cam surface  16 .  
     [0041] In addition, although the preceding description has described the gas spring  18  as being connected to a drop safe door  12 , the gas spring  18  may alternatively be connected to any other pivoting component. For example, FIGS.  8 - 10  show an embodiment where the gas spring  18  is connected to a chassis  62  having at least one bill validator  58  and at least one corresponding bill validator cassette  60  mounted thereon. However, although the chassis  62  is shown as having at least one bill validator  58  and at least one corresponding bill validator cassette  60  mounted thereon, the chassis  62  may alternatively have mounted thereon another type of drop safe component, such as a loose coin dispenser, a rolled coined dispenser, an envelope drop system or a door locking system, or any combination thereof.  
     [0042] In the embodiment of FIGS.  8 - 10 , the chassis  62  comprises two bill validator cassettes  60 . Although the chassis  62  may comprise any number of bill validator cassettes  60 , for clarity the following description will refer to the chassis  62  as having two bill validator cassettes  60 .  
     [0043] As shown in FIGS.  8 - 10 , each bill validator cassettes  60  is attached to a corresponding bill validator  58 . The bill validator  58  receives and validates paper currency. The bill validators  58  send validated paper currency to the bill validator cassette  60  for storage. Each bill validator cassette  60  is mounted to the chassis  62 , either directly (not shown) or through a mounting bracket  64  (as shown in FIGS. 8 and 9). As with the drop safe door  12 , the chassis  62  is relatively heavy and, without the aid of the gas spring  18 , has a tendency to slam shut when moved in a closing direction and a tendency to rapidly swing open when moved in an opening direction.  
     [0044] Consequently, the gas spring  18  is attached to the chassis  62  or mounting bracket, as described above with respect to the drop safe door  12 , to facilitate rotating the chassis  62  between an closed position (as shown in FIG. 8) and an opened position (as shown in FIG. 9). In one embodiment, the cam surface  16  comprises a fully closed detent  66  for holding the chassis  62  in the closed position and a fully open detent  46  for holding the chassis  62  in the fully open position as described above. In addition, the cam surface  16  may comprise the neutral point detent  42  as described above for holding the chassis  62  in the partially open position.  
     [0045] In another embodiment, the cam surface  16  comprises a counter balanced region. The counter balanced region is a region along the cam surface  16  wherein the sum of the forces on the cam bearing  26  approaches zero due to the counteracting forces of the weight of the chassis  62  and the force of the gas spring  18  on the cam bearing  26 . Thus, when the cam bearing  26  is in the counter balanced region, the chassis  62  is held in the partially open position. Alternatively, the cam surface  16  may comprise neither the neutral point detent  42  nor the counter balanced region.  
     [0046] In the depicted embodiment, the gas spring  18  is disposed between the bill validator cassettes  60 . However, in other embodiments, the gas spring  18  may be disposed in other positions, such as adjacent to the bill validator cassette  60 . Alternatively, more than one gas spring  18  may be mounted to the chassis  62 . For example, the chassis  62  may comprise one gas spring  18  adjacently disposed to each corresponding bill validator cassette  60 .  
     [0047] The preceding description has been presented with reference to presently preferred embodiments of the invention. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, spirit and scope of this invention. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.