Patent Publication Number: US-2010107323-A1

Title: Device With An Electric Field Sensor, Control Circuitry, And A Solenoid

Description:
FIELD OF THE INVENTION  
     This invention relates generally to devices, and more specifically to dental devices. 
     BACKGROUND OF THE INVENTION  
     Conventional dental operatories generally include an articulating dental chair for supporting a patient in a variety of positions to facilitate the performance of dental procedures and operations. For example, dental chairs are generally adapted to be raised and lowered relative to a floor surface, and to be moved between a first orientation where a seat back is inclined relative to a seat base to support the patient in a seated position, and a second orientation where the seat back is reclined to support the patient in a generally supine position. 
     The dental operatory may also include a dental delivery unit adapted to support various instruments and tools used during the performance of dental procedures. The delivery unit is typically provided with water and pressurized air for operating the instruments, and may include a tray for supporting instruments or other articles used by the practitioner. The delivery unit may be supported on a movable arm that facilitates positioning the unit and instruments adjacent the dental chair for convenient access by the practitioner during the performance of a procedure, then moved away to permit the patient to exit the dental chair when the procedure is complete. 
     Conventional dental operatories may further include a cuspidor provided adjacent the dental chair to permit patients to expel the contents of their mouths during or at the conclusion of the dental procedure, an adjustably positionable lamphead to illuminate the treatment area, and various other devices useful for the performance of dental procedures. Such devices may be supported on cabinetry or other structure positioned adjacent the dental chair for convenient access by the patient or the dental practitioner. 
     For instance, in operation, the dentist may initiate a dispense water function of the dental cuspidor to fill a cup with water for a dental patient. The dental patient may drink the water in the cup to rinse out his or her mouth. The patient may then spit out the water into a bowl of the dental cuspidor. To rinse the bowl, the dentist may initiate another dispense water function of the dental cuspidor to rinse out the bowl. Alternatively, the dental patient may initiate the dispense water functions to fill up the cup and rinse the bowl. 
     One drawback with contemporary systems is that some of the devices (e.g., dental cuspidors, etc.) on the dental operatories utilize membrane type buttons, springs, and other mechanical components to initiate the execution of a function of the device. However, these buttons, for example, often allow the ingress of fluids and debris such as dust and other particles or even fluids into the device, which in turn interfere with the function of the device by interfering with the air pressure that activates the springs. The interference often leads to variations and inconsistency in results. 
     For instance, although the dental cuspidor may be set up to fill a cup of a certain size with water such that subsequent cups of the same size can be filled in a similar manner, often, debris may enter the dental cuspidor, block the system, and cause variations in the amount of water that is dispensed. As such, some cups may be overfilled while others may be under filled. Moreover, often times a user may have to waste time and money seeking professional assistance (e.g., from the manufacturer) or replacing the dental cuspidor because of the debris. 
     Thus, new ways to operate devices, including dental devices, which improve the operational consistency of devices are needed; otherwise, users may continue to be hampered in their ability to maximize the use of their devices. 
     SUMMARY OF THE INVENTION  
     The invention addresses these and other problems associated with the prior art by providing a device such as a dental cuspidor or a dental delivery unit, with an electric field sensor, control circuitry, and a solenoid. The control circuitry is in electronic communication with the electric field sensor, and the solenoid is in electronic communication with the control circuitry. The electric field sensor has capacitive sensing and is operable to detect a change in capacitance. The control circuitry is operable to receive a signal from the electric field sensor indicative of a detected change in capacitance. The control circuitry is operable to actuate the solenoid in response to receiving the signal from the electric field sensor. 
     As such, those of ordinary skill in the art may appreciate that variations and other inconsistencies may be reduced because of the electronic communication between the components. Furthermore, the electric field sensor, the control circuitry, and the solenoid may facilitate use of the device by a user because a simple touch may initiate a desired function of the device, and input members that reduce the ingress of debris and fluids may be utilized to initiate the function. 
     In some embodiments, the device may comprise an electric field sensor having capacitive sensing and operable to detect a change in capacitance. The device may also include control circuitry in electronic communication with the electric field sensor, with the control circuitry operable to receive a signal from the electric field sensor indicative of a detected change in capacitance. The device may also include a solenoid in electronic communication with the control circuitry. The control circuitry is operable to actuate the solenoid in response to receiving the signal from the electric field sensor. 
     In some embodiments, the dental cuspidor may comprise at least one electric field sensor having capacitive sensing and operable to detect a change in capacitance. The electric field sensor is associated with a water dispensing function of the dental cuspidor. The electric field sensor may comprise a first layer, including an input member operable for controlling the water dispensing function of the dental cuspidor. The capacitance change is generated when the first input member is touched. The sensor may also include an electric field sensor layer disposed below the first layer. 
     The dental cuspidor may also include control circuitry in electronic communication with the electric field sensor, the control circuitry operable to receive a signal from the electric field sensor indicative of a detected change in capacitance. Additionally, the dental cuspidor may also include a solenoid in electronic communication with the control circuitry. The control circuitry is operable to actuate the solenoid in response to receiving the signal from the electric field sensor. The dental cuspidor may also include a valve coupled to the solenoid. The solenoid opens or closes the valve in response to actuation of the solenoid by the control circuitry. The dental cuspidor may also include a water dispenser coupled to the valve. The water dispenser operable to dispense water in response to the opening or closing of the valve by the solenoid. 
     In some embodiments, the dental delivery unit may comprise at least one electric field sensor having capacitive sensing and operable to detect a change in capacitance. The electric field sensor is associated with a brake release function of the dental delivery unit. The electric field sensor may comprise a first layer, including an input member operable for controlling the brake release function of the dental delivery unit. The capacitance change is generated when the input member is touched. The sensor may also include an electric field sensor layer disposed below the first layer. 
     The dental delivery unit may also include control circuitry in electronic communication with the electric field sensor, where the control circuitry is operable to receive a signal from the electric field sensor indicative of a detected change in capacitance. Additionally, the dental delivery unit may also include a solenoid in electronic communication with the control circuitry. The control circuitry is operable to actuate the solenoid in response to receiving the signal from the electric field sensor. The dental delivery unit may also include a valve coupled to the solenoid. The solenoid opens or closes the valve in response to actuation of the solenoid by the control circuitry. The dental delivery unit may also include a brake coupled to the valve. The brake is operable to release in response to the opening or closing of the valve by the solenoid. 
     The invention also addresses problems associated with the prior art by providing a method for operating the device that provides an input member for the device that controls a function of the device, and provides a capacitive field proximate to the input member. The method for operating the device may also sense a capacitive change in the capacitive field caused by the touch of a user, and in response to the capacitive change, actuates the solenoid to perform the function. 
     These and other advantages and features, which characterize the invention, are set forth in the claims annexed hereto and forming a further part hereof. However, for a better understanding of the invention, and of the advantages and objectives attained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there are described exemplary embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE 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. 
         FIG. 1  is a diagrammatic representation of one embodiment of a device consistent with the principles of the present invention. 
         FIG. 2  is a perspective view of an embodiment of a dental cuspidor consistent with the principles of the present invention. 
         FIG. 3  shows a detailed portion of the electric field sensors of the dental cuspidor of  FIG. 2 . 
         FIG. 4  is a cross sectional view of the dental cuspidor of  FIG. 2 . 
         FIG. 5  shows a detailed portion of the solenoids of the dental cuspidor of  FIG. 4 . 
         FIG. 6  is a perspective view of an embodiment a dental delivery unit consistent with the principles of the present invention. 
         FIG. 7  is a partial bottom elevation view of the dental delivery unit of  FIG. 6 . 
         FIG. 8  is a flowchart showing a method for operating the device of  FIG. 1  consistent with the principles of the present invention. 
     
    
    
     DETAILED DESCRIPTION  
     The invention addresses the problems with the prior art by providing a device such as a dental cuspidor or a dental delivery unit, with an electric field sensor, control circuitry, and a solenoid. The control circuitry is in electronic communication with the electric field sensor, and the solenoid is in electronic communication with the control circuitry. The electric field sensor has capacitive sensing and is operable to detect a change in capacitance. The control circuitry is operable to receive a signal from the electric field sensor indicative of a detected change in capacitance, and the control circuitry is further operable to actuate the solenoid in response to receiving the signal from the electric field sensor. A method is also provided herein. 
     In one embodiment, the device is in the form of a dental cuspidor. In another embodiment, the device in the form of a dental delivery unit. However, although the device may be in the form of a dental cuspidor or a dental delivery unit, the invention is not limited, and devices may include dental and/or medical devices, for example, with an electric field sensor, control circuitry, and a solenoid. Moreover, those of ordinary skill in the art will appreciate that the principles of the present invention may be utilized, for example, to replace a membrane button, to replace a switch, etc. in a device. 
     Turning now to the drawings, wherein like numbers denote like parts throughout the several views,  FIG. 1  generally illustrates a device  10  for implementation of the invention. In the device  10 , an input member  12  is positioned on a first layer  14  that sits over an electric field sensor layer  16 . The electric field sensor layer  16  contains an electric field sensor  18  that is positioned beneath the input member  12  and is operably coupled to control circuitry  20  in the device  10 . 
     Specifically, the electric field sensor  18  generates electric field  22  proximate the input member  12 , such as above the input member  12  in first layer  14 . When a user&#39;s finger  24  touches the input member  12 , the electric field  22  above that member  12  is disrupted. The user&#39;s finger  24  causes a change in the capacitance which causes a change in the electric field  22 , and the change is detected by the electric field sensor  18  in the electric field sensor layer  16  and electrically communicates the change to the control circuitry  20 . Next, the control circuitry  20  may actuate a solenoid  26 , which ultimately leads to the performance of the function associated with the input member  12 . 
     In some embodiments, device  10  may have more than one of the input member  12 , which may control similar functions or different functions. Moreover, a processor, or other processing circuitry, may be coupled to the control circuitry  20 . Those of ordinary skill in the art may also appreciate that it may be beneficial to create first layer  14  with a material that may be easily cleaned and/or that does not allow the ingress of fluids or other debris into the device  10 . Furthermore, those of ordinary skill in the art may appreciate that the human body acts as a ground causing the change in capacitance by disrupting the electric field  22 , which is detected by the electric field sensor  18 . Moreover, users may often times wear medical gloves or another barrier, and the electric field sensor  18  may nonetheless be able to sense a change in capacitance. 
       FIG. 2  illustrates a dental cuspidor  28  that may be utilized by a doctor, a dentist, a dental hygienist, a dental employee, a dental patient, etc, which may employ the touch switches described in relation to  FIG. 1 . The dental cuspidor  28  has a base portion  30 , a middle portion  32  coupled to the base portion  30 , and a platform portion  34  coupled to the middle portion  32 . The middle portion  32  has a first layer  36  on an external surface of the middle portion  32  with at least one input member  38  (e.g., an input member  38   a  and/or an input member  38   b ). The first layer  36  may consist of an injectable plastic. 
     A user may utilize the input members  38   a ,  38   b  to control different functions of the cuspidor  28 . A symbol  39  proximate input member  38   a  may indicate that this input member controls the function of filling a cup (not shown). A symbol  41  proximate input member  38   b  may indicate that this input member controls the function of rinsing bowl  40 . Other control functions may also be provided. Each of the input members  38   a ,  38   b  may be a depression (e.g., a circular depression, a square depression, a rectangular depression, etc.), etc. in first layer  36 . In other embodiments, the input members may be flush with the first layer  36  forming a smooth surface. The input members  38   a ,  38   b  may each generally have a flat, smooth surface that may be easily cleaned. Moreover, although two input members are illustrated, other embodiments may have more or fewer input members. 
     The middle portion  32  has a water dispenser  42 , such as a spigot, to rinse the bowl  40  with water. The water drains out of the bowl  40  via drain mechanism  44 . The platform portion  34  has a second water dispenser  46  used to fill a cup placed on cup holder  48  of the platform portion  34  with water. The dental cuspidor  28  may be attached to a dental operatory via attachment  50  (shown in phantom). The components interior to the base portion  30  and the middle portion  32  will be discussed further in connection with  FIGS. 3-5 . 
     Referring now to  FIG. 3 , each of the input members  38   a ,  38   b  (shown in  FIG. 2 ) may be associated with a corresponding electric field sensor  52   a ,  52   b . Specifically, the input member  38   a  for filling the cup has the electric field sensor  52   a  associated with it, and the input member  38   b  for rinsing the bowl  40  has the electric field sensor  52   b  associated with it. The electric field sensors  52   a ,  52   b  are interior to the first layer  36  of the middle portion  32 , and may generally reside behind the input members  38   a ,  38   b . The electric field sensors  52   a ,  52   b  are supported internally via supporting structure  53 . The electric field sensors  52   a ,  52   b  may be, for example, QTouch QT100 sensors from Quantum Research Group, or alternatively, the QT100A sensors from Atmel Corporation. 
     In accordance with one aspect of the invention, the electric field sensors  52   a ,  52   b  may each provide a capacitive field proximate to the input members  38   a ,  38   b  in first layer  36 . Specifically, the electric field sensors  52   a ,  52   b  may each include a copper surface over which the electrical field is generated. The electric field sensors  52   a ,  52   b  may also be equipped with capacitive sensing, which may be used to indicate that the corresponding input member has been touched by a user, such as by the finger of a user. A capacitance change will occur when either one of the input members  38   a ,  38   b  is touched, and the associated electric field sensor  52   a ,  52   b  detects the change in capacitance. 
     Turning to  FIG. 4  and  FIG. 5 , after one of the electric field sensors  52   a ,  52   b  senses that a particular input member  38   a ,  38   b  (shown in  FIG. 2 ) has been touched, the sensor may send a signal to control circuitry  54 , which may be implemented on a printed circuit board (PCB)  56 . Of note, the electric field sensors  52   a ,  52   b  may also include resistors, capacitors and other electrical components to send the signal, generate the electric field, and/or detect the change in capacitance. The electric field sensors  52   a ,  52   b  may also include the appropriate wiring and connectors for wire harnesses, and may be attached to cuspidor  28  via attachments  57 . 
     Generally, when the object is present in the capacitive field that is in contact with ground, the corresponding electric field sensor  52  recognizes the difference in the electric field between that electric field sensor  52  and ground and that electric field sensor  52  is activated. When that electric field sensor  52  is activated, it sends a signal to control circuitry  54  requesting it to turn on the appropriate solenoid  58  (e.g., solenoid  58   a  and/or solenoid  58   b ). Indeed, the control circuitry  54  may utilize transistor circuits to send electrical current to the appropriate solenoid  58 , which moves a spool to open the corresponding valve  60  (e.g., valve  60   a  and valve  60   b ). The solenoid  58   a , which may be used for filling the cup, opens valve  60   a  while solenoid  58   b , which may be used for rinsing bowl  40 , opens valve  60   b.    
     The valves  60   a ,  60   b  release system air from air introduce through storage valve  61  (seen in  FIG. 5 ), which receives air from air storage  63  (in  FIG. 5 ). The air then flows through valves  60   a ,  60   b  to the corresponding valves  62  (e.g., valve  62   a  and valve  62   b ). The valve  62   a  is actuated from the air and is used for dispensing water to fill the cup, and valve  62   b  (not shown in  FIG. 4 ) is actuated from the air and is used for rinsing bowl  40 . The air from valves  60   a  causes valve  62   a  to open, while the air from valve  60   b  causes valve  62   b  to open. The air travels to valves  62   a ,  62   b  via tubing  64   a ,  64   b . The valve  62   a  receives air from tubing  64   a  while the valve  62   b  receives air from tubing  64   b.    
     Tubing  66  and  68  may be utilized to carry water to the corresponding water dispensers  46 ,  42 . Specifically, tubing  66   a  and  68   a  carry water to dispenser  46  while tubing  66   b  and  68   b  carry water to dispenser  42  to rinse bowl  40 . Water from bowl  40  may exit cuspidor  28  through drainpipe  70  (shown in phantom). Additionally, a protective portion  72  may be utilized as internal support for the components of dental cuspidor  28 , and to protect the connections of tubing  68   a ,  68   b  with dispensers  46 ,  42 . Supporting structures  74  may also provide internal support for the dental cuspidor  28  and its components. 
     The valves  60   a ,  60   b  may be three-way valves that are normally closed. Actuation of one of the solenoids  58   a ,  58   b  by control circuitry  54  opens the corresponding valve  60   a ,  60   b , but once actuation of that valve  60   a ,  60   b  ceases, the air stops. Indeed, the control circuitry  54  may be operable to actuate the solenoids  58   a ,  58   b  for as long as the corresponding electric field sensor  52  detects the change in capacitance. Thus, the valves  60   a ,  60   b  are responsive to the control circuitry  54  and once actuating stops, the valves  60   a ,  60   b  may close. 
     The valves  62   a ,  62   b  may be pilot air valves or other type of valves. Moreover, the pilot-operated valves may be water valves that are normally closed two-way valves that require a pilot signal to open. Additionally, although dental cuspidor  28  has been generally described as having an input member  38 , an electric field sensor  52 , and a solenoid  58  with a valve  60  for each function, a single solenoid may be utilized with more than one electric field sensor  52  in some embodiments. 
     In some embodiments, the electric field sensors  52  may be integral with a printed circuit board (“PCB”)  56 , including a copper surface over which the electrical field is generated. When an object is present in this field that is in contact with ground, the electric field sensor  52  recognizes a change in the electric field and activates. Moreover, when the electric field sensor  52  is activated, it sends a signal to a controller PCB requesting it to open the appropriate valve  60 . A transistor circuit may be used to send an electrical current, which moves a spool in the solenoid  58  and opens the valve  60 . Indeed, those of ordinary skill in the art may appreciate that various modifications may be made to the structure and functionality consistent with the principles of the present invention. 
     Before turning to  FIG. 6  and  FIG. 7  for the dental delivery unit, it is worth noting that additional functionality may be performed via the electric field sensor  52 , control circuitry  54 , and solenoid  58  for a device, such as a dental cuspidor  28 . For example, there may be two circuits in the dental cuspidor, one to fill a cup with water, and one to rinse the bowl with water. There may be a microprocessor on the control circuitry  54  (e.g., controller PCB) used to control the amount of time to keep each solenoid valve open. To that end, there may be a push button switch or another electric field sensor on the dental cuspidor&#39;s control circuitry  54  (e.g., controller PCB) that is used in conjunction with the electric field sensor  52  and microprocessor to program this length of time. Indeed, the control circuitry  54  may be operable to actuate the solenoid  60  for as long as the change in capacitance is detected by the electric field sensor  52 , and that length of time may be determined and reused. As such, a user may be able to contact the fill cup input member  38   a  (shown in  FIG. 1 ) and have the cuspidor  28  fill a different cup for the same length of time without having to touch the input member  38   a  for that length of time. Moreover, the user may be able to more easily change the length of time if he or she starts using a different size cup, for example, by contacting the input member  38   a  for the new length of time. 
     Turning now to  FIG. 6 , this figure illustrates a dental delivery unit  76  that includes three electric field sensors  78  (shown in  FIG. 7 ), specifically, sensor  78   a  in area  80 , sensor  78   b  in area  82 , and sensor  78   c  in area  84 . The dental delivery unit  76  may also include control circuitry (not shown), and a solenoid (not shown) in area  86 , to release a brake (not shown). 
     The dental delivery unit  76  may be utilized to hold instruments such as dental instruments and/or associated materials. The dental delivery unit  76  has a base portion  88 , a top portion  90  with a tray  92 , and a sloping portion  94  with at least one instrument holder  96  (e.g., holders  96   a - 96   e ) and a touchpad  98 . 
     The touchpad  98  may include a screen  100  (e.g., a three and a half inch LCD display) and at least one button  102 . The touchpad may provide information about an apparatus that is coupled to (e.g., coupled directly to, coupled indirectly such by being in the same dental operatory, etc.) the dental delivery unit  76  such as an instrument in one of the instrument holders  96 , a dental chair associated with the dental delivery unit  76 , a light associated with dental delivery unit  76 , other apparatuses in the dental operatory, etc. Apparatuses may also include dental devices such as the dental cuspidor, the dental delivery unit, etc. Moreover, the buttons  102  may be used to navigate the screen  100  and/or may control the function of the apparatus such as to lower the chair, raise the chair, etc. Attachment  104  (in phantom) may be utilized to attach the dental delivery unit  76  to another apparatus like the dental chair. 
     As illustrated in  FIG. 7 , input members  78   a ,  78   b , and  78   c  are located beneath the sloping portion  94  in bottom portion  106 . Input member  78   a  is generally in area  80 , input member  78   b  is generally in area  82  beneath touchpad  98 , and input member  78   c  is generally in area  84 . Each of the input members  78   a ,  78   b , and  78   c  may have an electric field sensor and an electric field associated with it. Although three input members are illustrated, in some embodiments, fewer than three or more than three input members may be utilized. 
     The dental delivery unit  76  may normally be in a braked state, and when a user touches any one of the input members  78   a ,  78   b , and  78   c , the electric field sensor of the corresponding input member detects the change in capacitance, and the brake release function is initiated. As all the input members seek to initiate the brake release function, a single solenoid may be utilized to open or close a valve of the brake. 
     In a particular embodiment, for example, the dental delivery unit  76  may have three electric field sensors (not shown) that may be used to release a flex arm brake. Any one of them may request the control circuitry (e.g., controller PCB) to open the flex arm brake&#39;s solenoid valve, which sends a pilot signal to a normally open three-way valve. The flex arm brake may be activated with a pneumatic piston and the piston may normally be pressured with system air. The three-way valve may then be used to shut-off and relieve system air to the piston. In this system, the solenoid valve may be energized for however long the electric field sensor is activated. 
     Referring now to  FIG. 8 , a method of operating a device, in accordance with the invention, may involve a methodology that prevents inadvertent triggering of the electric field sensors. As shown in the flowchart  108 , an electric field, in some embodiments, is created above an input member by an electric field sensor as noted in block  110 . The electric field sensor monitors the electric field as noted in block  112 . When a user touches the input member (block  114 ), the user, having a different dielectric constant than air, causes a change in the capacitance. This capacitive change is detected by the electric field sensor (block  116 ). The capacitive change detected by the electric field sensor is electrically communicated to the control circuitry and sends a signal to the control circuitry as noted in block  118 . 
     The control circuitry may be configured to check the capacitive change detected by the electric field sensor against a threshold value (block  117 ), for example, to ignore inadvertent contact. For instance, there may be a capacitance change level threshold that may be utilized to determine if there is an engagement of the input member by a user, i.e., when the change level exceeds the threshold. Alternatively, there may be a time threshold to determine if the capacitance change exists for a certain amount of time or a duration beyond the threshold time. If the value of the capacitive change or the duration of the change does not exceed the specific threshold value, then the electric field sensor continues to monitor the electric field. Therefore, if a user inadvertently brushes past one of the input members, a signal may not result and false indications may be avoided, and control may return to block  112  to continue to monitor the electric field. If, however, the capacitive change level or duration does exceed the specific threshold value, then the signal is sent to the control circuitry as indicated block  118 . 
     Once the signal has been sent, the control circuitry sends an electrical current to the solenoid to actuate the solenoid, opening the valve, as in block  120 . Next, the air travels through the valve to open, as in block  122 . In other embodiments though, other methods may be used to open the second valve. 
     While the embodiments above have been illustrated using a capacitive sensing method which is determined by generating an electric field and sensing disturbances in the electric field, a person skilled in the art will recognize that other sensing methods may be utilized in place of the electric fields in the embodiments shown. Other embodiments may utilize capacitive matrix sensing as well as other techniques and still be within the scope of the invention. 
     Moreover, in some embodiments, a normally closed solenoid valve may be a normally open solenoid valve, which therefore closes upon actuation, for example. Indeed, those of ordinary skill in the art may appreciate that whether actuation opens or closes a valve depends upon the structure and general setup, but actuation by both opening or closing are contemplated within the scope of the present invention. As such, valves (e.g.,  62   a  and  62   b ) that open in the dental cuspidor may close, and the brake valve that closes in the dental delivery unit may open in some embodiments. 
     Furthermore, those of ordinary skill in the art may appreciate that the principles of the present invention may be utilized, for example, to replace a membrane button, purge at least one water line, replace a brake switch, etc. In particular, practically any switch may be replaced consistent with the principles of the present invention. 
     While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the application 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. Therefore, the invention in its broader aspects is not limited to the specific details or representative devices and method, and illustrative examples shown and described. Accordingly, departures may be made form such details without departure from the spirit or scope of applicant&#39;s general inventive concept.