Abstract:
A tilt mechanism is provided for a communication device enabling the communication device to be placed at a desired angular position during use. The tilt mechanism includes a biasing member that allows the user to consistently and easily set the angular position of the phone and without collapse or shifting of the communication device to another position. In the preferred embodiments, the biasing member is in the form of a leaf spring that biases the movement of a user-controlled component for setting the desired angular position.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a mechanism to adjust the angular position of a device, and more particularly, to an adjustable tilt mechanism for adjusting the angular position of a communication device such as a desktop telephone. 
     BACKGROUND OF THE INVENTION 
     For devices such as telephones, PDAs, and computers, it is desirable to provide a mechanism that allows a user to adjust the height and/or angle at which the device is positioned for use. The visual display for a conventional desktop telephone or other communication device may need to be placed at a particular angle so that the user can view the display without glare or to otherwise maximize visibility. In the case of a desktop telephone, the visual display may be provided within a single housing along with the telephone keypad. In the case of a laptop computer, the screen of the laptop computer rotates independently of the keyboard; however, the screen must be placed at a particular angle so that the user may best view the screen. With respect to other communication devices such as PDAs, one or more keypad controls are co-located with a screen display, and viewability of the screen is maximized at a particular angular position. 
     Providing a reliable mechanism to select and set the angle of the device is important in enabling the user to effectively use the device. Particularly for devices such as desktop telephones, the angle at which the telephone display is set is important since the telephone display may not be particularly bright or large, and any misalignment of the display may make viewing very difficult. 
     Mechanisms to control the angle at which a desktop telephone is placed have been provided in various forms. One prior art mechanism for providing an adjustable angle is a ratchet tilt mechanism. This mechanism enables a user to select a particular angular orientation for the telephone display through a ratcheting feature incorporated in the housing of the telephone. 
     While the ratchet tilt mechanism may be commonly used in many desktop telephones, adjustment components like the ratchet feature can be unreliable and often fail immediately after assembly or after the telephone has been in use for only a short time. Furthermore, many tilt mechanisms do not allow the user to easily adjust fine positioning of the angle of the telephone display, and therefore are not user-friendly. 
     Therefore, there is a need to provide a mechanically simple, yet reliable tilt mechanism to enable the user to easily adjust and set the angle at which a device is to be used. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a tilt mechanism is provided for adjustably positioning the angle at which a device such as a desktop telephone is placed with respect to a horizontal surface on which a base of the telephone rests. The tilt mechanism includes an improved biasing member that helps to ensure the tilt mechanism holds its selected position, as well as easing the manner in which the user selects a particular position. 
     The tilt mechanism of the present invention allows a user to select the angular position of the communication device with use of a conventional push button feature and without forcing the user to adjust any other part of the device. 
     In one aspect of the invention, it can be considered a communication device incorporating the tilt mechanism. In another aspect of the invention, it can be considered a tilt mechanism with potential use with a communication device and many other types of devices that may require positioning at a desired angle. In another aspect of the invention, a useful sub-combination is provided wherein a tilt mechanism does not require a base, and the element that is used to incrementally adjust the angular position of the device can directly contact the surface upon which the device rests. In yet another aspect of the present invention, a method is provided for adjustably positioning the angle of one device with respect to a horizontal mounting surface, and more particularly, a method of adjustably positioning a housing of a communication device with respect to a base of the communication device that rests on the mounting surface. 
     These and other features and advantages of the present invention will become apparent from review of the following detailed description, taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a conventional communication device in the form of a desktop telephone, including a mechanism for adjusting the angle of the communication device with respect to a base placed on a horizontal surface; 
         FIG. 2  is a fragmentary perspective view of internal components of the housing that are used to adjust the angled position of the housing; 
         FIG. 3  is a fragmentary perspective view of the tilt mechanism of the present invention installed in the housing of the communication device; 
         FIG. 4  is an enlarged fragmentary perspective view of the tilt mechanism of the present invention, showing the mechanism in a locked position; 
         FIG. 5  is another enlarged fragmentary perspective view of the tilt mechanism illustrating the mechanism in an unlocked position; 
         FIG. 6  is yet another perspective view of the tilt mechanism of the present invention illustrating the tilt mechanism in the unlocked position; 
         FIG. 7  is a greatly enlarged perspective view of a tilt block incorporating a return spring in a second embodiment of the tilt mechanism of the present invention; 
         FIG. 8  is another perspective view illustrating the return spring installed in the tilt block; and 
         FIG. 9  is a perspective view of the second embodiment of the present invention illustrating the tilt block installed in the housing of the device. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a conventional prior art communication device  10 . Specifically,  FIG. 1  illustrates a desktop telephone including a base  12 , a housing  14 , and a handset  16  mounted to the housing  14 . A cord  18  interconnects the handset to the housing. A control panel  17  includes a plurality of keys enabling a user to dial the phone, as well as to conduct a number of other functions with the communication device. The control panel may also include one or more user screens (not shown) enabling the user to view a number of functions of the communication device. 
     The angular position of the housing  14  may be set by a tilt mechanism, as discussed further below. Components of the tilt mechanism seen in this Figure include a tilt foot or tilt support  52  having a first end that rotates about a fixed point in the housing  14 , and a second end that is selectively placed within a desired setting between teeth  22  formed within channel  23 . More specifically, a setting is defined as a selected gap located between two adjacent teeth  22 . 
       FIG. 2  illustrates the interior of the housing  14  with interior components of the communication device removed for clarity, except for the tilt mechanism. The tilt mechanism of the present invention is similar to the prior art tilt mechanism  44 , with the exception that different structure is used to bias the operation of the plunger rod  28 , as discussed below. Therefore, for basic operation of the prior art tilt mechanism  44 , reference can also be made to  FIGS. 3-6 , which illustrate the tilt mechanism of the present invention. Also, the same reference numbers used to describe the prior art denote the same or similar elements in the present invention. 
     With respect to the prior art tilt mechanism  44 , it includes a user control including plunger rod  28  having an exposed plunger button  30  protruding from one side  33  of the housing. The underside  24  of the housing  14  includes various internal protruding features  26 ,  27  and  29  that are used to accommodate attachment of the communication device components and/or are provided to strengthen the housing and segregate components from one another. Brackets  32  support the plunger rod  28 , and the opposite end of the plunger rod includes a contact tab  34  that engages a tilt block  36 . The tilt block  36  is laterally secured by a plurality of tabs  37  that extend from the underside  24  of the housing. However, the tilt block is allowed to displace longitudinally by action of the plunger rod  28  in the directions D as shown. Slots  38  are formed in the tilt block. A pair of stop tabs  40  protrudes from the underside  24  of the housing. The tabs  40  are received in the slots  38 . The stop tabs  40  delimit the longitudinal displacement of the tilt block. A plurality of cantilever springs  42  are used to bias the actuation of the plunger rod  28 . Specifically, in  FIG. 2 , a first pair of cantilever springs  42  extend from and are integral with the plunger rod  28 , while a second pair of cantilever springs  42  extend from and are integral with the tilt block. In the prior art, these cantilever springs are molded plastic members that are formed when the plunger rod and tilt block are injection molded. The first pair of cantilever springs  42  have free ends that press against the housing feature  26  that straddles the plunger rod, while the other pair of cantilever springs  42  have free ends that press against the other housing features  29  located laterally adjacent the tilt block  36 . Protruding feature  26  partially covers the tilt mechanism  44  as seen from the view of  FIG. 2 . 
     Referring specifically to  FIGS. 4 and 5  of the present invention for better understanding of how the tilt mechanism operates, the tilt mechanism  44  is shown in greater detail wherein the tilt block  36  includes a pawl  56  that selectively engages gaps between teeth  48  formed on ratchet drum  46 . Ratchet drum  46  is mounted within the housing  14  by pins  47  that are rotatably mounted in the housing  14 . A rotational spring  50  is provided on one or both of the pins  47  in order to provide some rotational bias for the ratchet  46 . Integral with and extending from the ratchet  46  is the tilt foot  52 . The second or free end of the tilt foot  52  includes extensions  54  that are selectively lodged within the desired setting, as discussed above with respect to  FIG. 1 . 
     Again referring to  FIG. 1 , when the housing  14  is moved to its most horizontal position with respect to base  12 , the extensions  54  travel forward in the channel  23  towards the forward portion  35  of the base, and the tilt foot  52  then lies collapsed within the recess  23 . If the user decides to create some angular inclination of the housing  14  with respect to the base  12 , the user simply grasps the housing  14  and rotates the housing upwards until the desired inclination is obtained. As the housing  14  is rotated upwards, the extensions  54  travel across the teeth  22  until the extensions are lodged in the desired setting. Simultaneously, as the housing is rotated, the tilt mechanism  44  rotates about pins  47 , and the teeth  48  sequentially contact the pawl  56  until rotation is stopped. Then the pawl  56  engages one of the incremental gaps between adjacent teeth  48 . As the housing is rotated to the user&#39;s desired position, a distinct clicking noise is generated caused by the pawl  56  progressively advancing into each gap by the spring force generated from the cantilever springs  42  and rotational spring(s)  50 . A distinct angular setting is available corresponding to each audible clicking sound. Springs  42  and spring(s)  50  provide some biasing force such that if the user releases the housing  14 , the plunger  28  retracts and causes the pawl  56  to engage the aligned gap between teeth  48 , thereby locking the housing  14  in its set position. If it is desired to place the housing  14  more towards a horizontal orientation with respect to the base  12 , the user depresses the plunger button  30  causing the plunger  28  to travel so the contact tab  34  engages the tilt block  36  and displaces it so that the pawl  56  is separated from the ratchet  46  and the teeth  48 . When the plunger button is depressed, the housing can be freely rotated with no engagement of the pawl against the ratchet. 
     One inherent drawback with respect to the prior art device of  FIG. 2  is that the molded cantilever springs  42  relax over time, and crisp, clean selection of a particular setting is made much more difficult, since the biasing force provided by the cantilever springs  42  decrease over time, resulting in the pawl  56  failing to cleanly engage the gaps on the drum  46  between the teeth  48 . Accordingly, a user may choose a particular angular setting, and the pawl  56  may fail to adequately engage the ratchet  46 , resulting in the housing  14  collapsing back upon the base  12  or resulting in slippage of the pawl  56  and placement of the pawl in another gap between the teeth. Another disadvantage associated with the cantilever springs include inconsistency in performance based upon molding defects. Slight defects in the shape and location of the springs can result in substandard performance, and because the springs are relatively small, molding defects are common. Additionally, inconsistency in assembly of the tilt mechanism can contribute to substandard spring performance. If the plunger rod is not precisely positioned, one or more of the cantilever springs may not be placed in the correct position to press against the designated internal housing feature, thereby resulting in partial or complete loss of spring force at that misaligned location(s). 
     In accordance with the present invention, in order to overcome the disadvantages outlined above with respect to the prior art shown in  FIG. 2 , a different biasing member is provided to ensure that once the user has chosen the desired angular placement of the housing  14 , the tilt mechanism does not fail causing the housing to shift or fall towards the base. 
     In a first embodiment, the biasing member of the present invention is shown in  FIGS. 3 and 4  as a bumper spring  60  that is placed between the most distal or forward surface  39  of the tilt block  36  and a surface  31  of one of the internal features  27  formed on the underside of the housing. The bumper spring  60  has a first end  62  that abuts the distal surface  39 , while a second end  64  engages the surface  31  of feature  27 . The spring  60  also has an extension  65  that extends over the planar surface of the feature  27 , thereby helping to retain the spring in place. Preferably, the bumper spring  60  is in the form of a leaf spring made of metal such as stainless steel. The leaf spring has a uniform width and thickness and is shaped to accommodate the space or gap between surfaces  31  and  39 . The type of metal as well as the thickness and width of the spring can be chosen such that optimal force is placed against distal surface  39  in response to actuation by the user of the plunger rod  28 , thus insuring a crisp, reliable engagement and disengagement of the pawl  56  with the ratchet  46  and the teeth  48 . With use of a metallic spring, concerns regarding plastic relaxation are overcome, and the bumper spring is a much more efficient and reliable solution for biasing the movement of the plunger  28 . 
       FIGS. 3 and 4  illustrate the tilt mechanism in the locked position wherein the pawl  56  is engages the ratchet  46 .  FIGS. 5 and 6  illustrate the tilt mechanism  36  in an unlocked position wherein the plunger  28  has been actuated by pressing the button  30  thereby displacing the tilt block  36  and causing the pawl  56  to disengage the ratchet  46 . Accordingly, a small space is visible between the pawl  56  and the ratchet  46 . 
     Referring to  FIGS. 7-9 , a second embodiment of the present invention is shown. Specifically, in lieu of the bumper spring  60 , a return spring  80  is provided. Referring first to  FIG. 7 , the return spring  80  is shown prior to assembly with the tilt block  36 . The return spring  80  includes an elliptical shaped body  82 , and a pair of spaced fingers  84 . Referring to  FIG. 8 , fingers  84  are inserted within the respective slots  38 , and are held in frictional engagement against interior planar edges  70 . When installed, the spring fingers  84  are slightly spread so that adequate friction is maintained to hold the return spring in place.  FIG. 9  shows the tilt block installed wherein the return spring  80  contacts the surface  31  of internal feature  27 , thereby providing a biasing force against movement of the tilt block caused by plunger rod  28 . The return spring  80  may also be selected such that the type of material and size of the spring results in an optimal biasing force. 
     With respect to both embodiments of the present invention, the only structural modifications necessary to the prior art communication device are elimination of the cantilever springs  42 , and addition of the selected spring or biasing member  60  or  80 . Therefore, the modified tilt mechanism of the present invention is provided in a structurally simple and cost-effective manner. The leaf spring configurations of springs  60  and  80  are reliable, and simply changing the width or thickness of the spring, or selection of a different material may easily modify an optimum biasing force. 
     In accordance with the method of the present invention, precise control of a tilt mechanism is achieved by compression of a spring  60 ,  80  whereby the pawl  56  reliably engages the ratchet  46  based on user control of the button  50 . The method is achieved with existing components of the communication device, and does not require any further structural changes to the communication device as discussed above. The method also does not require any change in the general manner by which the user selects the angular position of the housing. 
     Although the present invention has been illustrated with respect to a conventional desktop telephone, it shall be understood that the tilt mechanism of the present invention can be used in a number of different types of communication devices, wherein the angle of the communication device with respect to a base is adjusted for user convenience. For example, in lieu of a desktop telephone, the tilt mechanism can be used with other communication devices such as personal digital assistants (PDAs) or computing devices having a soft or VOIP phone. Thus, it shall be understood that the housing  14  can be used to house not only a desktop telephone, but also other types of communication devices, and the base  12  can represent any structural member that helps stabilize the communication device on a horizontal surface. 
     While the present invention has been discussed with respect to one or more preferred embodiments, it shall be understood that various other changes and modifications of the invention can be made within the spirit and scope of the invention, in accordance with the scope of the claims appended hereto.