Abstract:
A cordless vehicle wheel alignment sensor head with interchangeable batteries includes easy to replace rechargeable batteries, thus eliminating the need for a service call to replace the batteries and allows the operator to swap a nearly depleted battery set with a fully or partially charged battery set. The sensor head includes a battery compartment door which slides upwards without pivoting about or detaching from the sensor head, and allows the batteries to pop out and be replaced. The battery compartment door also includes at least one battery engaging protrusion which presses against the battery at a non-contacting end of the rechargeable battery when the battery compartment door is closed. Accordingly, with the battery compartment door closed, the battery is tightly held in place and pressed into a pair of retractable pins that result in electrically coupling the battery to the sensor circuitry.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims priority to Provisional U.S. Application Serial No. 60/288,457, filed on May 4, 2001, the disclosure of which is incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to an alignment system and, more particularly, to such an apparatus improved with easily removable, rechargeable batteries to power an alignment sensor head module.  
         BACKGROUND OF THE INVENTION  
         [0003]    Battery technology has made significant advances over the past few years. As a result batteries with higher capacity are available at lower cost. Furthermore, these higher capacity batteries are rechargeable and take less physical space since they are not as bulky as their predecessors were.  
           [0004]    Consequently, devices that require electric energy to operate are now available with an integrated battery module rendering the devices cordless. One family of devices in particular involves automotive service equipment, such as vehicle wheel alignment systems. These devices are designed to include cordless alignment sensor heads including an integrated battery module. The sensors are applied, e.g., to a wheel of a vehicle in order to make necessary measurements relating to the alignment of that wheel. The information is then transferred to a console, which includes a computer, for analyzing the sensed information. The console is typically located in the alignment shop where the alignment is taking place.  
           [0005]    The batteries in these sensors are typically integrated into the battery compartment of the sensor so as to prevent them from becoming loose and compromising electrical contact which results in losing alignment data. Accordingly, conventional cordless sensors are not amenable to rechargeable batteries that are easily removable from the sensor. Thus, when the sensor&#39;s battery runs out, instead of just replacing the battery, the whole unit is taken out of service and placed in a charge station while its battery is being recharged. This will result in the sensor being out of service for several hours while its battery is being recharged. Further, these sensors typically utilize batteries which are not amenable to being easily swapped, as they are held in place by fasteners because the batteries have to be able to withstand a great deal of vibration due to the very nature of the shop and particularly when placed on the wheel during alignment. Once the battery&#39;s life runs out, i.e., the battery is no longer capable of being recharged, a service technician is usually called to remove the old batteries and install a new set.  
           [0006]    Another problem occurs when the battery runs out while the technician is performing an alignment. In this case, the technician has to plug in cords from the console to power the sensor unit externally, or remove the sensor and store it at the console&#39;s storage station to commence a battery recharging operation. Neither alternative is desirable. The first option of externally powering the sensor by plugging in cords, effectively makes the unit non-cordless, eliminating the advantages of a cordless unit. The second option results in having to halt the alignment process while the sensor unit is placed in the storage station at the console to be recharged.  
           [0007]    [0007]FIGS. 1A and 1C show perspective views of a conventional cordless sensor with an integrated battery module according to the prior art. The cordless sensor  10  typically includes gelled electrolyte cell batteries (known in the art as a “gel cell”) such as battery  30  as illustrated in FIG. 1B. These types of batteries are typically heavy and bulky, and require a physical connection to a terminal. These batteries also typically require heavy brackets to keep them in place and substantially free from movement. Replacing these batteries is a difficult and tedious task typically requiring a service technician to disassemble the sensor module to gain access to the batteries.  
           [0008]    In order to replace the battery  30  of the cordless sensor  10 , a technician will first remove the cover  22  from the main sensor body  12 . Then the technician will disconnect any wires attached to the battery  30 . If any brackets holding the battery  30  in place have been used, they are removed in order to free the battery. The technician reverses this process to install a new battery resulting in additional down time.  
           [0009]    Accordingly, there exists a need for a cordless battery operated alignment sensor head having an easily removable and rechargeable battery.  
         SUMMARY OF THE INVENTION  
         [0010]    The ability to provide a battery-powered cordless wheel alignment sensor head with an easily removable and rechargeable battery is demonstrated. A first rechargeable battery may be replaced by a second rechargeable battery once the first battery is at or near the end of its charge life. The depleted battery is easily removed by sliding upwards a compartment door to a battery compartment placed in the rear of the cordless sensor module. The battery is electrically coupled to the sensor via contacts that includes a pair of retractable pins. The pins provide the contact to the positive and the negative terminals of the battery which, in the example shown, are located at the same end of the battery, i.e., the end opposite to the end closest to the battery compartment door. However, other configurations are possible. Accordingly, the user is able to easily change the battery without the need for a service call. In this way, the sensor unit need not be placed out of service while its battery is being replaced or recharged. The sensor&#39;s battery is simply removed and quickly replaced by a fully or partially charged battery.  
           [0011]    In another embodiment, the sensor head includes a battery module placed in the rear of the sensor unit. Access to the battery module may be blocked, e.g., by a battery compartment door which is slideably attached thereto. The door therefore does not detach from or pivot about the unit, which prevents accidental breakage or loss of the door piece. The embodiment is mechanically designed to offer battery interchangeability and operator convenience when the battery needs to be removed. Additionally, the battery door includes protrusions placed on the inner surface of the battery door which presses onto a battery when in the closed position resulting in the battery being substantially secure in place and free of movement as the sensor is applied to measure alignment characteristics of a vehicle.  
           [0012]    Once the battery door is in the closed position, an inward protrusion located at the inner surface of the battery compartment door presses onto a battery in order to keep the battery firmly in place so as not to compromise electrical contacts made at the contacting-end of the battery. The contacting-end of the battery includes both a positive and a negative terminal, which are seperated by a battery cap. A pair of retractable pins properly located at a PCB board located inside the battery compartment are used for electrically coupling the battery with the PCB board.  
           [0013]    Additional advantages and novel features will be set forth in part in the description, which follows, and in part will become apparent to those skilled in the art upon examination of the various embodiments. The embodiments shown and described provide an illustration of the best mode contemplated. Modifications are possible in various obvious respects without departing from the spirit and scope thereof. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. The advantages may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    Reference is made to the attached drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein:  
         [0015]    [0015]FIG. 1A is a perspective front side elevational view of a conventional cordless alignment sensor module.  
         [0016]    [0016]FIG. 1B is a battery used with a conventional cordless alignment sensor module.  
         [0017]    [0017]FIG. 1C is a perspective backside elevational view of a conventional cordless alignment sensor module.  
         [0018]    [0018]FIG. 2 is perspective side elevational view of an exemplary alignment sensor head.  
         [0019]    [0019]FIG. 3 is a side elevational view of an exemplary alignment sensor head.  
         [0020]    [0020]FIG. 4 is a bottom plan view of an exemplary alignment sensor head.  
         [0021]    [0021]FIG. 5 is a perspective view of an exemplary cordless alignment sensor module with removable and rechargeable batteries according to one embodiment, with one housing side removed.  
         [0022]    [0022]FIG. 6 is a perspective view of a portion of an exemplary battery module according to one embodiment.  
         [0023]    [0023]FIG. 7A is a perspective view of an exemplary battery compartment, with its compartment door open, and corresponding batteries ready for placement according to one embodiment.  
         [0024]    [0024]FIG. 7B is a perspective view of an exemplary battery compartment with its compartment door open and corresponding batteries in place according to one embodiment.  
         [0025]    [0025]FIG. 8A is an end view of an exemplary battery compartment, with its compartment door open and corresponding batteries in place according to one embodiment.  
         [0026]    [0026]FIG. 8B is an end view of an exemplary battery compartment according to one embodiment, with its compartment door closed.  
         [0027]    [0027]FIG. 9A is a frontal view of an exemplary battery compartment door according to one embodiment.  
         [0028]    [0028]FIG. 9B is a side view of an exemplary battery compartment door according to one embodiment.  
         [0029]    [0029]FIG. 10 is a perspective view of a part of the battery compartment showing the batteries and terminal board.  
         [0030]    [0030]FIG. 10A is a perspective view of a part of the battery compartment showing the battery&#39;s contact with retractable pins.  
         [0031]    [0031]FIG. 11A is a side sectional view of the battery compartment with the battery compartment door open and batteries halfway in place according to one embodiment.  
         [0032]    [0032]FIG. 11B is a side sectional view of the battery compartment with the batteries fully locked in place. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0033]    A new cordless alignment sensor head including an easily removable and rechargeable battery is disclosed. The cordless alignment sensor module is used as an integral part of an alignment system, such as, but not limited to, a vehicle wheel alignment system and the like. The sensor&#39;s batteries can be swapped easily and rapidly without the loss of alignment data already collected. Further, the sensor can remain operational with a fully charged battery while its depleted battery is being recharged.  
         [0034]    Referring to FIGS.  2 - 4 , an exemplary alignment sensor head  100  is illustrated. The alignment head  100  includes a housing  110  that has a hollow interior and is capable of securely receiving all the components necessary for performing an alignment procedure. The housing  110  can be constructed from various materials, such as structural foam or plastic, using economical molding processes. As illustrated in FIG. 3, the housing  110  includes a front portion  112 , a rear portion  114 , and a central portion  116 . A front bumper  118  is attached to the side of the front portion  112 . Additionally, a main bumper  120  is attached to the bottom of the housing  110  and extends from the central portion  116  to the rear portion  114 .  
         [0035]    The alignment head  100  can be provided with a user interface  122  disposed on a top surface of the housing  110 , as shown in FIG. 2. The user interface  122  includes a keypad  124 . During alignment procedures, an operator can input information and/or select menu items using the keypad  124 . Accordingly, the keypad  124  can include a plurality of keys sufficient for both entering letters and numbers, as well as navigating through menus. Alternatively the alignment head  100  does not require a user interface  122 . Rather, information is entered and displayed externally using, for example, an external control system (not shown) that can include a CRT display unit coupled to a keyboard, or personal computer (not shown) executing software for performing the alignment.  
         [0036]    The housing  110  is in the form of a left cover  128  and a right cover  130 , as shown in FIG. 4. The left and right covers  128 ,  130  are adapted for engagement with each other using mating components, to form the housing  110 . In addition to the use of mating components, various fasteners can be used to secure the left cover  128  to the right cover  130 . The interior of the housing  110  includes various moldings designed to retain securely a plurality of components when the left cover  128  and right cover  130  are attached to each other. According to such a feature, the components are not displaced if the alignment head  100  is subject to impact.  
         [0037]    Referring now to FIG. 5, a perspective view of an exemplary alignment sensor with its right cover intact and its left cover removed so as to expose the left half of the sensor head. The cordless alignment sensor  500  includes a main sensor body  512 , one or more rechargeable batteries  530 , a battery compartment  540 , and a battery compartment door  550 . The main sensor body  512  also houses the battery compartment  540 , which in turn holds the rechargeable batteries  530 . The battery compartment  540  contains a battery interface printed circuit board “PCB” (not shown, but described later). Description of structural features not related to the invention is omitted for brevity.  
         [0038]    Door  550  is constructed and arranged to slide vertically within opposite side located channels or guides, (as depicted such as guide  562 ). The door  550 , so arranged does not pivot about and is not removeable from, the body  512 . To replace the batteries  530 , the user simply slides the battery compartment door  550  upward into an open position as depicted in FIG. 5, and pulls the batteries out of the compartment  540 . The battery compartment door  550  holds the batteries  530  in place and in contact with a contact (not shown). The battery compartment door includes an inward protrusion located in the area opposite to the darkened circle  560  on the outer surface of the door  550  shown in FIG. 5. This protrusion corresponds to protrusion  758  depicted in the embodiment of FIG. 9B, element  758 . The protrusion helps keep the batteries firmly in place when the battery door is slid downward into a closed position.  
         [0039]    Accordingly, this embodiment provides a cordless alignment sensor with easily removable and rechargeable batteries. The embodiment may be used for any alignment application, such as with a vehicle wheel alignment system, and the like. Additionally, any type of rechargeable battery such as Nickel Cadmium and the like may be used to provide the necessary power to the alignment sensor module. Because the door  550  cannot pivot on, or separate from, the sensor body, the door is not apt to become misplaced or damaged by shop use.  
         [0040]    Referring to FIG. 6, an exemplary battery compartment depicted in FIG. 5 that contains battery interface PCB and rechargeable batteries is illustrated. The battery compartment  540  includes two rechargeable batteries  530 , a battery module  610 , a battery stop  620 , battery terminals  630 , and battery interface PCB  640 . To install new batteries, the operator slides the batteries  530  into the battery module  610  until the batteries  530  engage the battery terminals  630  and the battery stop  620 . The battery terminals  630 , which include both negative and positive terminal connections, electrically couple battery  530  to the battery interface PCB  640 . The operator then slides the battery compartment door  550  downwards (as shown in FIG. 5) which causes the protrusions located on the inner surface of the door  550  to compress the batteries into the interface PCB  640  and make good electrical contact. The protrusion is designed such that once the battery door in the closed position, the battery is substantially secure in place and electrical connection is not compromised as the unit is applied to measure alignment of a vehicle wheel when the apparatus is used for that purpose.  
         [0041]    Referring to FIGS. 7A, 7B, and  10 , a perspective back view of an exemplary sensor head is again illustrated. FIG. 10 shows a perspective view of a part of the battery compartment according to another embodiment. FIG. 7A, shows the battery compartment door in the open position, and batteries  730  and  731  ready for deployment, while FIG. 7B shows the battery compartment door in the open position but the batteries  730  and  731  fully in place.  
         [0042]    Referring to FIGS. 8A and 8B, an end view of the sensor head is illustrated. In FIG. 8A, the battery compartment door is in the open position, while FIG. 8B shows the battery compartment door is in the closed position. The battery compartment door  750 , which is visible in the closed position, includes the battery compartment door handle  752  and a pair of battery engaging protrusions mounted (for example, by molding) on the inside of the battery compartment door  750 . The pair of protrusions can be visualized as being on the opposite sides of the circles  756  shown on the battery compartment door  750 .  
         [0043]    As shown in FIG. 8B, when the batteries  730  are locked in place and the battery compartment door  750  in the closed position, each battery engaging protrusion  758  (shown as dashed lines in FIG. 8A since located on the inside of the door  750 ) presses against a battery end  734 . Once the batteries  730  are so engaged, the batteries are secure in place and thus the electrical couplings at the opposite terminals of the batteries are not compromised.  
         [0044]    Referring to FIGS. 9A and 9B, a front and side view of an exemplary battery compartment door is illustrated. The battery compartment door  750  includes the battery compartment door handle  752 , and battery engaging protrusions  758  (shown in FIG. 9B) which create the grooved and slightly concave circles  756  on the frontal side of the battery compartment door  752 . Although the embodiment includes a pair of protrusions, the invention is not thus limited. The number of protrusions is related to the number of batteries used. Although in the embodiments shown, only two batteries have been utilized, the invention is not limited to any particular number of batteries used.  
         [0045]    Batteries  730  and  731  (FIG. 7A) include a contacting-end and a non-contacting end. The contacting end is the end that provides electrical contact with the interface PCB  1010  as shown in FIG. 10 and FIG. 10A. As shown in FIG. 10A, the battery cap  732  is used to isolate the positive terminal from the negative terminal of the battery  730 . Accordingly, the retractable pin  1022  and  1020  are situated such that pin  1022  contacts battery  730  outside cap  732 , e.g., the positive terminal, and pin  1020  contacts battery  730  inside the cap  732 , e.g., the negative terminal.  
         [0046]    The non-contacting end is the opposite end and makes no electrical connection. The protrusions  758  located on the inside of the battery door are designed to press against the battery end  734  in order to keep the battery in place. The advantage of the battery door mechanism is in the ability to keep the battery relatively free of movement when the unit is in use.  
         [0047]    The battery compartment door, which includes a handle  752  (as shown in FIG. 7A) is not visible when in the open position since it slides upwards into a cavity. Accordingly, the only visible part of the battery compartment door when in the open position is the handle  752 .  
         [0048]    When batteries need to be replaced, the operator slides the battery compartment door  750  upward by using the door handle  752 . The door  750  will slide all the way up until the door handle  752  reaches the opening  760 , at which point, the batteries can be easily pulled out and replaced with fully charged batteries. To close the battery compartment door  750 , the operator downwardly presses on the handle  752 . Once the battery engaging protrusion  758  presses against the battery end  734  and the battery compartment door is in the closed position, the battery is held tightly in place. The size of the protrusion is such that the batteries are substantially secure in place.  
         [0049]    Referring to FIGS. 10, 10A,  11 A and  11 B, perspective views of a part of the battery compartment according to an embodiment is illustrated. The battery compartment  712 , which is shown with batteries  730  half inserted, includes the interface PCB  1010  which in turn includes a pair of retractable pins  1020  and  1022  per battery (one per terminal). When the batteries are fully in place and the battery door  750  in the closed position (as shown in FIG. 11B), the retractable pins  1020  and  1022  are pressed in and the batteries  730  are electrically coupled to the interface PCB  1010 . The pins  1020  and  1022  are placed on the PCB  1010  such that one pin makes a connection with the center of the battery  730  and inside the cap  732  (e.g., the positive terminal) while the other pin makes connection with the side of the battery and outside the cap  732  (e.g., the negative terminal).  
         [0050]    Also, the battery engaging protrusion  758  is shown in FIG. 11A when the battery door  750  is in the open position. Once the battery door  750  is pressed downward, with the battery biased mechanically outward by pins  1020  and  1022 , the battery engaging protrusion is pressed into the battery end  734  of the battery  730  in order to keep the battery firmly in place so that electrical connection at the opposite terminal is not compromised.  
         [0051]    In the previous descriptions, numerous specific details are set forth, such as specific materials, structures, processes, etc., in order to provide a thorough understanding of the present invention. However, as one having ordinary skill in the art would recognize, the present invention can be practiced without resorting to the details specifically set forth. In other instances, well known processing structures have not been described in detail in order not to unnecessarily obscure the invention. For example, although the concepts described herein, in the field of vehicle wheel alignment, the concept can be applied to other alignment applications such as vehicle body alignment, aircraft wing alignment and the like.  
         [0052]    Only examples of their versatility are shown and described. It is to be understood that various other combinations and environments are possible, as are changes or modifications to the concept expressed herein.