Damage-resistant vibrator assemblies and wireless communications devices incorporating same

A vibrator assembly includes an electric motor, a shaft driven by the motor, and a cylindrical weight coaxially positioned on the shaft free end, wherein the cylindrical weight has a center of gravity that is radially offset from the shaft axis. The cylindrical weight includes a first portion that is lighter in weight than a second portion. When the vibrator assembly is installed within an electronic device, the cylindrical shape of the weight limits the amount of shaft deflection that can occur when the electronic device is dropped or subjected to other impact forces.

FIELD OF THE INVENTION

The present invention relates generally to vibrator assemblies, and more particularly to vibrator assemblies used within electronic devices.

BACKGROUND OF THE INVENTION

Many electronic devices such as radiotelephones and pagers include indicators to alert a user that something has happened or that some action is required. For example, an audible ringer can be used to indicate that a telephone call is being received or that a page has been received. Alternately, a vibrating assembly that causes an electronic device to vibrate can be used to provide silent indication. Such vibrating assemblies typically include a small electric motor, referred to as a vibrator motor, that drives a rotating shaft having an unbalanced or “eccentric” weight (i.e., a weight with a center of gravity that is radially displaced from the axis of rotation), thereby causing a vibration when the shaft rotates.

Unfortunately, conventional vibrator assemblies can be damaged when electronic devices containing them are dropped. Depending on the orientation of the vibrator assembly eccentric weight at the moment of impact, the rotating vibrator shaft may deflect enough to cause damage thereto (i.e., become bent or otherwise damaged). A bent or otherwise damaged rotating shaft can negatively effect the performance of a vibrator assembly. If the weight is in a favorable position, it will hit the surrounding structure of the electronic device, and the shaft will likely not be bent or otherwise damaged. However, since the weight is normally formed as a half cylinder with the shaft in the center of the cylinder, there is a high probability that the shaft may be bent in one direction. Accordingly, there is a need for improved vibrator assemblies that avoid damage to a rotating shaft when dropped and subjected to various impact forces.

SUMMARY OF THE INVENTION

In view of the above discussion, vibrator assemblies that are configured to resist damage thereto when dropped or subjected to other impact forces are provided. According to some embodiments of the present invention, a damage-resistant vibrator assembly includes an electric motor, a shaft driven by the motor, and a cylindrical weight coaxially positioned on the shaft free end, wherein the cylindrical weight has a center of gravity that is radially offset from the shaft axis. According to some embodiments of the present invention, the cylindrical weight includes first and second portions that are radially offset from one another relative to the axis, and wherein the first portion is lighter in weight than the second portion. For example, the first portion is formed from material (e.g., plastic) having a first density and the second portion is formed from material (e.g., metal) having a second density that is greater than the first density. According to some embodiments of the present invention, the first portion of the cylindrical weight may be hollow. When the vibrator assembly is installed within an electronic device, the cylindrical shape of the weight limits the amount of shaft deflection that can occur when the electronic device is dropped or subjected to other impact forces. This is because deflection of the shaft causes the cylindrical weight to contact other internal components and/or the housing of the electronic device.

According to some embodiments of the present invention, a damage-resistant vibrator assembly includes an electric motor, a shaft driven by the motor, and an eccentric weight fixed to a side of the shaft such that a center of gravity of the weight is radially offset from the shaft axis. A distal end of the eccentric weight includes an annular protection ring that is coaxially positioned relative to the shaft axis and that gives the eccentric weight a cylindrical configuration at the distal end thereof. When the vibrator assembly is installed within an electronic device, the cylindrical shape of the eccentric weight distal end limits the amount of shaft deflection that can occur when the electronic device is dropped or subjected to other impact forces. This is because deflection of the shaft causes the distal end of the eccentric weight to contact other internal components and/or the housing of the electronic device.

DETAILED DESCRIPTION OF THE INVENTION

Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity.

It will be understood that, although the terms “first”, “second”, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a “first” element, component, region, layer or section discussed below could also be termed a “second” element, component, region, layer or section without departing from the teachings of the present invention. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

Referring toFIG. 1, a conventional wireless communications device will now be discussed in further detail. As used herein, the term “wireless communications device” may include, but is not limited to, a cellular wireless terminal with or without a multi-line display; a Personal Communications System (PCS) terminal that may combine a cellular wireless terminal with data processing, facsimile and data communications capabilities; a PDA that can include a wireless terminal, pager, Internet/intranet access, Web browser, organizer,. calendar and/or a global positioning system (GPS) receiver; and a conventional laptop and/or palmtop receiver or other appliance that includes a wireless terminal transceiver. Wireless communications devices may also be referred to as “pervasive computing” devices and may be mobile terminals.

Damage-resistant vibrator assemblies, according to embodiments of the present invention, may be incorporated into a wireless communications device, for example, the wireless communications device10illustrated inFIG. 1. As illustrated, the wireless communications device10includes a housing12. The housing12includes a top portion13and a bottom portion14connected to the top portion13, thus forming a cavity therein. The top and bottom housing portions13,14house a keypad15, which may include a plurality of keys16, a display17, and electronic components (not shown) that enable the wireless communications device10to transmit and/or receive communications signals.

Referring now toFIG. 2, a conventional arrangement of electronic components that enable a wireless communications device, such as illustrated inFIG. 1, to transmit and/or receive wireless terminal communication signals will be described in further detail. As illustrated, an antenna22for receiving and/or transmitting wireless communication signals is electrically connected to a radio-frequency (RF) transceiver24that is further electrically connected to a controller25, such as a microprocessor. The controller25is electrically connected to a speaker26that is configured to transmit a signal from the controller25to a user of a wireless communications device. The controller25is also electrically connected to a microphone27that receives a voice signal from a user and transmits the voice signal through the controller25and transceiver24to a remote device. The controller25is electrically connected to the keypad15and the display17that facilitate wireless communications device operation. Also, the controller25is electrically connected to an audio ringer28and vibrator29, which are used to indicate that a call or some other message is being received.

Referring now toFIG. 3, a damage-resistant vibrator assembly30according to some embodiments of the present invention is illustrated. It will be understood that the vibrator assembly30may be configured for use with various electronic devices, such as wireless communications devices as discussed above. The illustrated vibrator assembly30includes an electric motor32disposed within a housing34. One or more electrical contacts36are configured to provide electrical power to the electric motor32when the vibrator assembly30is installed within an electronic device (e.g., mounted on a printed circuit board, etc.), as would be understood by one skilled in the art. The illustrated vibrator assembly30includes a shaft38that is driven by the motor32and that has a free end38aextending outwardly from the housing34. The shaft38is configured to rotate about an axis A, as would be understood by one skilled in the art. A cylindrical weight40is coaxially positioned on the shaft free end38a.

The illustrated cylindrical weight40includes first and second portions42,44that are radially offset from each other and that are formed from materials having different densities. For example, the first portion42comprises material having a first density (e.g., polymeric material such as polycarbonate, etc.) and the second portion44comprises material (e.g., metal such as magnesium, etc.) having a second density that is greater than the first density. As such, the center of gravity of the cylindrical weight40is radially offset from the axis A (i.e., the center of gravity is located in the second portion44).

The first portion42may be formed from virtually any type of material that is lighter in weight (i.e., less dense) than the material of the second portion44. According to some embodiments of the present invention, the first portion42may be hollow. According to some embodiments of the present invention, the first and second portions42,44may be formed from similar materials, but the first portion42is hollow while the second portion is solid. The hollow configuration of the first portion42causes the first portion to be lighter in weight than the second portion44, thereby causing the center of gravity to be located in the second portion44. As long as the center of gravity is located in the second portion44(i.e., the center of gravity is radially separate from the axis of rotation A), the vibrator assembly will vibrate when the shaft38is rotated, as would be understood by one skilled in the art of the present invention.

The first and second portions42,44may be joined together in any of various ways including, but not limited to, adhesively joined, mechanically joined, etc. As would be understood by one skilled in the art, mechanically joining the first and second portions42,44together includes, but is not limited to, the use of clips, threaded fasteners, keys, pins, etc.

The illustrated first and second portions42,44are substantially half-cylindrical portions. However, the first and second portions42,44may have different configurations. For example, the first portion42may be three-quarters of a cylindrical portion and the second portion44may be a one-quarter cylindrical portion, etc. As used herein, the term “half-cylinder” and “half-cylindrical” are intended to include shapes that are more than and less than a half-cylinder.

The shape of the cylindrical weight40protects the shaft38from damage when an electronic device incorporating the vibrator assembly30is dropped or subjected to impact forces. The weight first portion42provides sufficient strength to withstand impact forces etc., that may otherwise cause the shaft38to bend or become damaged as a result of the off-centered mass of the weight second portion44. In other words, the cylindrical configuration of the weight40provides resistance to bending forces on the shaft38because the cylindrical configuration causes the weight40to be able to contact other internal components and/or the housing of an electronic device and thereby prevent the shaft38from deflecting enough to cause damage thereto.

Referring now toFIG. 4, a vibrator assembly130according to other embodiments of the present invention is illustrated. It will be understood that the vibrator assembly130may be configured for use with various electronic devices, such as wireless communications devices as discussed above. The illustrated vibrator assembly130includes an electric motor132disposed within a housing134. One or more electrical contacts136are configured to provide electrical power to the electric motor132when the vibrator assembly130is installed within an electronic device (e.g., mounted on a printed circuit board, etc.), as would be understood by one skilled in the art. The illustrated vibrator assembly130includes a shaft138that is driven by the motor132and that has a free end138aextending outwardly from the housing134. The shaft138is configured to rotate about an axis A, as would be understood by one skilled in the art.

An eccentric weight140is fixed to a first side of the shaft138, as illustrated. The illustrated eccentric weight140has a substantially half-cylinder configuration. However, eccentric weight140may have various configurations (i.e., may have a configuration that is more than a half cylinder or may have a configuration that is less than a half cylinder).

The illustrated eccentric weight140includes a distal end140athat includes an annular protection ring142coaxially positioned relative to the shaft axis A, as illustrated. The annular protection ring142serves to protect the shaft138from damage when an electronic device incorporating the vibrator assembly130is dropped or subjected to impact forces. The annular protection ring142is configured to provide sufficient strength to withstand impact forces etc., that may otherwise cause the shaft138to bend or become damaged as a result of the off-centered mass140. In other words, the eccentric weight140has a cylindrical configuration at its distal end140aas a result of the annular protection ring142, and this cylindrical configuration provides resistance to bending forces on the shaft38because the cylindrical configuration causes the eccentric weight140to be able to contact other internal components and/or the housing of an electronic device and thereby prevent the shaft138from deflecting enough to cause damage thereto.

The annular protection ring142does not contain as much mass as the eccentric weight140. As such, the center of gravity of the weight140is radially offset from the axis A, thus the vibrator assembly will vibrate when the shaft138is rotated, as would be understood by one skilled in the art of the present invention.

According to some embodiments of the present invention, the eccentric weight140and the annular protection ring142are formed from the same material and/or materials having the same density. According to other embodiments of the present invention, the eccentric weight140and the annular protection ring142are formed from different materials and/or materials having different densities. For example, the annular protection ring142may be formed from material having a first density and the eccentric weight140may be formed from material having a second density that is greater than the first density.

Damage-resistant vibrator assemblies, according to embodiments of the present invention, may have various shapes, configurations, and/or sizes. Embodiments of the present invention are not limited to the illustrated configurations of the vibrator assemblies30,130inFIGS. 3 and 4.