This invention pertains to carts with lockable drawers, and more particularly to a locking system for medical carts.
Carts with lockable drawers are used for many applications. For example, a medical cart having lockable drawers is used to administer medication to patients in hospitals or other care facilities. A typical medical cart has casters located at the bottom of the cart to permit easy movement of the cart by attending nurses to various patients' rooms. The cart also has one or more drawers for storing patients' medicines. Typically, each drawer is dedicated to storing the medication for an individual patient. Because the cart is used to store medications for several patients and is movable from room to room, controlling access to the contents of the cart to prevent theft or misuse of medication, and thereby protect the patients is important. One such medical cart, as described above, is disclosed in U.S. Pat. No. 5,743,607 to Tuefel et al., which patent is commonly held by the Assignee of the present invention and hereby incorporated by reference in its entirety.
Conventional medical carts have manually actuated locks which are operable to permit users to selectively lock and unlock the drawers of the cart to thereby control access to the contents stored in the drawers. Conventional medical carts have also been provided with electronically actuated locks, whereby the drawers of the cart are unlocked in an automated fashion after a user enters an access code into a keypad located on an external portion of the cart. When medical carts have been provided with both manual and electronically actuated lock mechanisms, these mechanisms have typically been provided as separate and independent systems, each individually capable of releasing the drawers of the cart from a locked condition. Because the manual and electronically actuated systems are separate, this necessarily adds to the overall complexity and cost of the carts.
There is thus a need for a simple cart locking system which overcomes drawbacks of the prior art such as those described above.
The present invention provides a locking system for a cart wherein a manually actuated lock mechanism is integrated with an electronically actuated lock mechanism to provide a compact and efficient system for controlling access to the contents of the drawers of a cart. It is recognized that unlocking the drawers of a cart using an electronically actuated lock mechanism may be initiated, for example, when a user manually enters an access code into a keypad. Accordingly, reference to the lock mechanisms as “manually actuated” and “electronically actuated,” as used herein, is intended to describe the structure or manner in which the respective lock mechanisms operate to unlock the drawers of a cart.
In an exemplary embodiment, the locking system includes a cam that is operatively coupled to a drawer of the cart to permit the drawer to be secured within the cart. The cam has a locked position wherein the drawer is prevented from being moved from the closed position to the open position, and an unlocked position wherein the drawer is released for movement from the closed position to the open position.
The locking system further includes a manually actuated lock mechanism and an electronically actuated lock mechanism. The manually actuated lock mechanism is operable to permit manual manipulation of the cam between its locked and unlocked positions. In one embodiment, the manually actuated lock mechanism comprises a lock core that is manually movable between a first position corresponding to the locked position of the cam, and a second position corresponding to the unlocked position of the cam.
The electronically actuated lock mechanism cooperates with the manually actuated lock mechanism to permit automatic operation of the locking system as desired. The electronically actuated lock mechanism may be actuated when a user enters an appropriate access code into a keypad on the cart, or may be actuated by a control system of the cart according to predetermined conditions. In an exemplary embodiment, the electronically actuated lock mechanism comprises a release member engageable with the lock core of the manually actuated lock mechanism to permit automatic movement of the lock core between its first and second positions, i.e., from the locked position toward the unlocked position, or from the unlocked position toward the locked position. In another exemplary embodiment, the electronically actuated lock mechanism comprises a drive motor coupled to the release member and configured to selectively move the release member in directions toward the respective first and second positions of the lock core.
In another aspect of the invention, a method of securing contents in a drawer of a cart having a locking system as described above, comprises selectively moving the manually actuated lock mechanism from a locked condition to an unlocked condition to release a drawer of the cart for movement between closed and open positions. In one embodiment, the method includes manually moving the manually actuated lock mechanism from the locked condition to the unlocked condition. In another embodiment, the method includes automatically moving the manually actuated lock mechanism from the locked condition to the unlocked condition.
These and other objects, advantages, and features of the invention will become more readily apparent to those of ordinary skilled in the art upon review of the following detailed description of various exemplary embodiments, taken in conjunction with the accompanying drawings.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.
Referring to
Referring now to
With continued reference to
The lock core 42 includes a selectively retractable lock pin 60 protruding from an upper surface of the lock core 42. The lock pin 60 may be selectively caused to retract within the lock core 42 by manual manipulation of a key 62 inserted into a keyway 64 of the lock core 42. In the first, locked position of the lock core 42, the lock pin 60 engages a spring-biased lock catch 66 which protrudes into the first channel 44 (when not urged from the first channel 44 by the electronically actuated lock mechanism described below) to engage the pin 60 and thereby retain the lock core 42 in the first position as best depicted in
The locking system 12 further includes an electronically actuated lock mechanism configured to move the actuating member 32 between the locked and unlocked position without the need for a key 62 to manually operate the lock core 42. In the exemplary embodiment shown, the electronically actuated lock mechanism includes a release member 80 slidably disposed within a second channel 82 formed between the first and second housing halves 46a, 46b. The release member 80 includes a release catch 84 having a first surface 86 configured to engage the lock pin 60 to thereby prevent the lock core 42 from moving in a direction toward the second, unlocked position relative to the release member 80. A second surface 88 of the release catch 84 is inclined with respect to the lock pin 60 so that the lock pin 60 is caused to retract within the lock core 42 as the release member 80 is moved in a direction toward the second position of the lock core 42 to engage the second surface 88 of the release catch 84 with the lock pin 60.
The electronically actuated lock mechanism further includes a drive motor 90 operatively coupled t6 the release member 80 and actuable to move the release member 80 in a direction toward the second position of the lock core 42 or, alternatively, in a direction toward the first position of the lock core 42. The drive motor 90 has an output shaft 92 coupled by coupling members 93a, 93b to a lead screw 94 that extends through the second channel 82 in the housing 46 to engage the release member 80. Drive motor 90 is secured to the cart frame 20 by a mounting plate 89 and fasteners 91a, 91b. The release member 80 is formed with internal threads 96 which engage the lead screw 94 whereby rotation of the output shaft 92 in a first direction causes the release member 80 to move toward the second position of the lock core 42. Likewise, rotation of the output shaft 92 in an opposite direction causes the release member 80 to move in a direction toward the first position of the lock core 42.
The drive motor 90 is coupled by wires 98 to a power supply (not shown) and a control circuit 100 (see
A secondary control circuit 101 may be provided to receive input from the keypad 102, or other user input device, and to communicate with control circuit 100 when a valid access code has been entered. While the user input device has been shown and described herein as a keypad 102 for entering an access code, it will be recognized that the input device may alternatively be a barcode scanner, a magnetic stripe reader, a device for verifying a bio-identification metric, or any other device suitable for receiving an input parameter and limiting access to the cart 10.
Referring now to
In the exemplary embodiment depicted in
To manually unlock the drawers 16 of the cart 10, the access key 62 is inserted into the keyway 64 of the lock core 42 and is actuated by rotating the key 62 to retract the lock pin 60 within the lock core 42 as best depicted with reference to
When it is desired to subsequently lock the drawers 16 of the cart 10 after manually unlocking them, the lock core 42 may be moved from the second position to the first position by manually pushing the lock core 42 into the housing 46 to thereby engage the lock pin 60 with the release catch 84 in the first, locked position. The lock pin 60 is displaced by the sloped, second surface 88 of the release catch 84 as the lock core 42 is moved from the second position to the first position. After the lock pin 60 has passed the first surface 86 of the release catch 84, the lock pin 60 snaps back into the extended position whereby the first surface 86 of the release catch 84 engages the lock pin 60 and prevents movement of the lock core 42 from the first position toward the second position.
Alternatively, the locking system 12 of the cart 10 may be operated by utilizing the electronically actuated lock mechanism. Operation of the locking system 12 in this mode may be advantageous, for example, when the key 62 for the locking system 12 is unavailable. With reference to
When it is desired to re-lock the drawers 16 of the cart 10, or when the control circuit 100 otherwise determines that the drawers 16 of the cart 10 should be locked, the drive motor 90 is energized to rotate the lead screw 94 in a direction to move the release member 80 in a direction toward the first position of the lock core 42 whereby the release catch 84 engaged with the lock pin 60 causes the lock core 42 to move from the second, unlocked position to the first, locked position, as depicted in
Alternatively, after the locking system 12 has been unlocked electronically, and is in the position illustrated in
When the medical cart 10 has been locked manually after having been unlocked electronically, as described above and depicted in
The locking system 12 of the present invention may therefore be operated to lock and unlock the drawers 16 of the medical cart 10 either electronically or manually as described above. Advantageously, the locking system 12 of the present invention permits users to selectively lock or unlock the drawers 16 of the cart 10 manually or electronically, regardless of whether the drawers 16 have been previously locked or unlocked either manually or electronically. To facilitate the proper operation of the cart 10, the locking system 12 further includes sensors configured to detect the various conditions of the locking system 12. In the exemplary embodiment shown, the locking system 12 includes a first sensor 110 to detect whether the lock core 42 is in the first, locked position. In this embodiment, the first sensor 110 comprises a switch that is actuated by the carriage bolt 50 that couples the actuating member 32 to the lock core 42 and which extends through the slots 52a, 52b formed in the first and second housing halves 46a, 46b.
In another embodiment, the locking system 12 further includes second and third sensors 112, 114 configured to determine when the release member 80 has reached desired limits of travel in both the direction toward the first position of the lock core 42 and in the direction toward the second position of the lock core 42. In the exemplary embodiment shown, the second and third sensors 112, 114 comprise optical sensors positioned within the housing 46 to detect when the release member 80 has reached the respective limits of travel. The first, second, and third sensors 110, 112, 114 are mounted to a circuit board 116 and communicate with the control circuit 100. A conductive member 118 is attached to the housing 46 and is operatively coupled to the cart frame 20, such as by contact with a fastener 120, to dissipate static electricity from the housing 46 and thereby protect sensors 110, 112, 114 and circuit board 116.
The sensors 110, 112, 114 provide signals to the control circuit 100 which are used by the control circuit 100 to determine when the drive motor 90 should be de-energized to stop the release member 80 at the respective limits of travel, and to determine when the release member 80 must be moved toward the first position to disengage the lock catch 66 and thereby unlock the system 12 electronically subsequent to manual locking of the system 12, as described above.
While the present invention has been illustrated by the description of an embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept.