Patent Publication Number: US-6662971-B1

Title: Automatic pressing mechanism

Description:
BACKGROUND 
     1. Field of the Invention 
     This invention relates to pressing mechanisms. In particular, the invention relates to automatic pressing mechanisms. 
     2. Description of Related Art 
     There are many applications that require a pressing mechanism to press or squeeze a deformable or collapsible object or material. Examples of these applications include food preparation, food stuffing, squeeze tube dispensers, paper pressing. Typically these applications are performed manually where the user presses a roll against the object or material, or simply use hand to squeeze the material out of the container. This manual method is laborious, inaccurate, and time-consuming. 
     In addition, many popular products for home and business uses are contained in squeeze tubes. Examples of the products include toothpaste, lotion, cream, soap, shampoo, hair conditioner, medicated creams, and bath gels. These tubes are usually dispensed by manually squeezing the tube. To remove the contents out as completely as possible, it is recommended that the tube is squeezed from one end toward the tube opening end. However, doing so requires the tube users to exercise some force and pressure on the tube. For young children, old, weak or sick people, this may be a problem. Even healthy adults sometimes find it inconvenient to do so. 
     Therefore, there is a need to have a technique for a pressing mechanism that can overcome the above drawbacks. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the present invention will become apparent from the following detailed description of the present invention in which: 
     FIG. 1 is a diagram illustrating a press unit in which one embodiment of the invention can be practiced. 
     FIG. 2 is a diagram illustrating an electrical press assembly according to one embodiment of the invention. 
     FIG. 3 is a diagram illustrating an electrical pressing mechanism according to one embodiment of the invention. 
     FIG. 4 is a diagram illustrating a cross-sectional side view of an electrical press assembly according to one embodiment of the invention. 
     FIG. 5 is a diagram illustrating a cross-sectional side view of a mechanical press assembly according to one embodiment of the invention. 
     FIG. 6 is a diagram illustrating a rotation lock assembly of a mechanical press assembly according to one embodiment of the invention. 
    
    
     DESCRIPTION OF THE INVENTION 
     In one embodiment of the invention, a press assembly includes a gear assembly, a threaded rod, and a roller assembly. The gear assembly causes a rotational movement when activated. The threaded rod is coupled to the gear assembly and rotates in direction of the rotational movement caused by the gear assembly. The roller assembly is coupled to the threaded rod and moves linearly between a first end and a second end along guide slots when the threaded rod rotates. 
     In the following description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the present invention. In other instances, well-known structures are shown in block diagram form in order not to obscure the present invention. 
     FIG. 1 is a diagram illustrating a press unit  100  in which one embodiment of the invention can be practiced. The press unit  100  includes an enclosure  110 , a press assembly  170 , and an optional power adapter  180 . Note that the press unit  100  may be mechanical or electrical. A mechanical pressing unit does not need the power adapter  180 . 
     The enclosure  110  houses the press assembly  170  and provides access for the user to activate various actions on the press assembly  170 . Typically, the enclosure  110  is made of durable material including plastic, metal, or any other suitable material. The design of the enclosure  110  corresponds to the environment where the unit  100  is used. The press unit  100  may be positioned vertically or horizontally depending on how the press assembly  170  is used. For example, when the unit  100  is used as a toothpaste dispenser, it may be positioned vertically. When the unit  100  is used as a food preparation unit, it may be positioned horizontally. In the following description, references will be made with respect to vertical placement of the press unit. It is contemplated that when the unit  100  is place horizontally, the terms “upward”, “up”, “downward”, and “down” may be replaced by appropriate descriptors (e.g., “left”, “right”). The enclosure  110  includes a base  120 , a holder  130 , an activator access area  135 , a cover  140 , an open cover button  145 , an upward switch  150 , and a downward switch  155 . For a mechanical press unit, the upward and downward switches  150  and  155  may not be needed. 
     The base  120  provides support for the press unit  100  when it is placed vertically and stands on a flat surface. The holder  130  provides placement of activators for roll presser or accessories. For example, when used as a toothpaste dispenser, the holder  130  may contain toothbrushes, dental accessories such as floss dispenser, etc. The activator access area  135  defines an access area to allow an activator instrument (e.g., a toothbrush, a cup, a finger) to activate the press assembly  170 . This access area  135  may include an opening with proper guides to help aligning the activator instrument. The cover  140  provides cover for the press assembly  170 . In normal use, the cover  140  is in closed position. The cover  140  may be opened to allow the user to replace the element being pressed, such as the toothpaste. The open cover button  145 , when pressed, activates the cover  140  in the open position. The cover  140  may be partially or fully opened around a hinge  142 . The cover  140  may be made by a transparent material such as clear plastic so that the user can see the internal of the press unit. This may allow the user to decide if a press material or object  240  (e.g., toothpaste tube) needs to be replaced. The upward and downward buttons  150  and  155  allow the user to control the moving elements in the press assembly  170  to move upward or downward, respectively. For example, when the toothpaste tube needs to be replaced, the roll member in the press assembly  170  may be at the bottom location. The user presses the upward button  150  so that this roll member is moved upward. Then, the user presses the cover button  145  to open the cover  140 , removes the used toothpaste tube and replaces with a new one. 
     The press assembly  170  provides an automatic pressing mechanism to press or squeeze a press object or material. The press assembly  170  may be operated mechanically or electrically. The press assembly  170  may be integrated with the enclosure  110  or removable. The press assembly  170  is described in FIG.  2 . 
     The power adapter  180  provides electrical power to the press assembly  170  when it is electrically implemented. For electrical press assembly  170 , the power adapter  180  may also be optional because batteries may be used to provide power. The power adapter  180  may be implemented as a wall-mounted adapter. 
     FIG. 2 is a diagram illustrating an electrical press assembly  170  according to one embodiment of the invention. The electrical press assembly  170  includes a housing  210 , a fixture  220 , a roller assembly  230 , a threaded rod  250 , a gear assembly  260 , an activator assembly  265 , a motor  270 , a control circuit board  280 , and a battery holder  290 . It is contemplated that the electrical press assembly  170  may contain more or less components than the above depending on the usage. 
     The housing  210  holds the press object  240 . The press object  240  may be a squeeze tube like the toothpaste, lotion, bath gel, or any other materials that need to be pressed or squeezed, such as food materials, chemical compounds, building materials, industrial materials. The dimensions of the housing  210  depend on the press object  240 . The housing  210  may be made by any suitable material such as plastic or metal, or any combination. The housing  210  has guide slots  215  on two sides to guide the roller assembly  230  as it moves along from one end to another. The guide slots  215  may be straight or curved depending on the shape of the press object  240  and the desirable pressing actions. The housing  210  may have a housing opening  217  to accommodate the release of the content of the press object  240  if necessary (e.g., squeezing the toothpaste out of the toothpaste tube). 
     The fixture  220  may be part of the housing  210  or may be separated and connected to the housing  210  by some fastening mechanism such as screwing or glue. The fixture  220  is positioned between the roller assembly  230  and the threaded rod  250  to provide a surface against which the press object  240  is pressed when the roller assembly  230  moves along the guide slots  215 . The fixture  220  is typically approximately parallel to the threaded rod  250 . The fixture  220  may be formed to have a curved or slanted portion to accommodate the shape of the pressing element  240  such as at the opening end of a squeeze tube. 
     The fixture  220  may contain upper and lower switches  212  and  214  and a presence detector  216 . The upper limit switch  212  is used to detect when the roller assembly  230  moves to the upper end. The upper limit switch  212 , when activated, may de-energize the motor  270 . For example, when the user pushes the upward switch  150 , the roller assembly  230  moves upward until it reaches and activates the upper limit switch  212 . This switch  212 , once activated, de-energizes the motor  270  to stop the movement of the roller assembly  230 . The lower limit switch  214  is used to indicate when the roller assembly  230  moves to the lower end. It may be activated directly by the roller assembly  230 . The presence detector  216  detects if the press object  240  has been placed on the fixture  220 . When the press object  240  is placed on the fixture  220 , it activates the presence detector  216 . The presence detector  216  may be a switch, a circuit connection assembly, a sensor, etc. Note that not all of the switches or detectors are used. These switches and detectors provide signals to the circuit board  280  and can be activated by a number of methods. For example, the roller assembly  230  may be automatically moved upward to the upper limit switch  212  as soon as it touches the lower limit switch  214  or when the cover  140  is opened. 
     The roller assembly  230  is coupled to the threaded rod  250  so that it moves linearly between the two ends of the housing  210  along the guide slots  215  when the threaded rod  250  rotates. One of the main features of the present invention is the conversion of the rotational movement of the threaded rod  250  into a linear movement of the roller assembly  230 . As the roller assembly  230  moves along the guide slots  215  in parallel with the fixture  220 , it creates a pressing action on the press object  240  or flattens the object  240 . If the press object  240  is a squeeze tube, this pressing action effectively squeezes the content of the squeeze tube out of the tube opening. Therefore, the press object  240  or material can be pressed automatically. 
     The threaded rod  250  is coupled to the gear assembly  260  and rotates in the direction of the rotational movement caused by the gear assembly  260 . The threaded rod  250  may be made by any suitable material, preferably by metal to provide sufficient mechanical strength. The pitch, size, and the number of the threads on the threaded rod  250  depend on the application and usage. A fine pitch threaded rod provides smooth and slow linear motion. The threaded rod  250  is inserted through the housing  210  through two holes on two ends so that it can be placed firmly beneath the fixture  220  in horizontal position when the press unit  100  is placed horizontally. 
     The gear assembly  260  causes a rotational movement when activated. When operated electrically, the gear assembly is connected to the motor  270  as shown in FIGS. 2 to  4 . When operated mechanically, the gear assembly  260  is connected to a winder assembly as shown in FIG.  5 . The gear assembly  260  is connected to the threaded rod  250  to cause a rotational movement of the threaded rod  250  as the gear assembly is activated. 
     The activator assembly  265  may include an instrument to activate the movement of the roller assembly  230 . In addition, it may also house a seal or a gasket  218  in order to close the opening of the press object  240  when in normal state. This is useful to avoid leakage of the contents, especially when the press object  240  is positioned upright and contain leakable materials such as toothpaste. When the activator assembly  265  is activated, it opens the gasket  218  so that the content inside the press object  240  may be squeezed out. A spring  224  may be used to exert a return action on the instrument. 
     The motor  270  generates rotational force when energized. The motor  270  is a direct current (DC) motor which may provide a forward rotation and a reverse rotation according to the polarities of the applied voltage. The control circuit board  280  contains a control circuit to provide control actions to the motor  270 . The control circuit is connected to the activator  265 , the upward and downward switches  150  and  155  (FIG.  1 ), the upper and lower switches  212  and  214 , the presence detector  216 , and the motor  270  to energize the motor when the activator  265 , or the upward and downward switches  150  and  155 , is activated. The control circuit provides first and second control actions corresponding to first and second rotational directions, one is clockwise and the other is counterclockwise. In essence, the control circuit switches the polarities of the voltage applied to the motor  270  to energize the motor  270  to generate the desired rotational direction. The battery holder  290  holds a battery or batteries to provide power to the motor  270 . The battery or batteries may not be needed when the press assembly  170  operates directly from the line power. 
     FIG. 3 is a diagram illustrating an electrical pressing mechanism according to one embodiment of the invention. 
     The roller assembly  230  shown in FIG. 2 includes a roller member  310  and a carrier  330 . The roller member  310  is positioned in an approximately parallel direction to the fixture  220  (FIG. 2) with a distance sufficiently short so that the roller member  310  applies sufficient pressure on the press object  240  (FIG. 2) when moving linearly along the guide slots  215 . The roller member  310  includes a roll  315  and a roller rod  317 . The roll  315  is cylindrically shaped with a hollow channel. The roll  315  may be made by any suitable material, preferably metal to provide sufficient mechanical strength when pressed against the press object  240 . The roller rod  317  is inserted though the cylindrical-shaped roll via the hollow channel. The roller rod  317  may also be integrated to the roll  315 . The roller rod  317  provides attachment to the carrier  330 . 
     The carrier  330  is an approximately U-shaped member attached to two ends of the roller member  310  via the roller rod  317 . In one embodiment, the carrier  330  has two holes through which the roller rod  317  is inserted. The carrier  330  is also attached to the threaded rod  250  (FIG. 2) by a nut  335 . The nut  335  is permanently glued to the carrier  330  by a strong adhesive. Typically the nut  335  is a hex nut and is fitted to the threaded rod  250  so that the carrier  330  moves linearly when the threaded rod  250  rotates. The carrier  330  and the nut  335  may be made of any suitable material, preferably metal and compatible with the roll member  310 . 
     The threaded rod  250  is attached to the carrier  330  through the nut  335 . As the threaded rod  250  rotates, the nut  335  advances in a linear fashion and moves the carrier  330  and the roll member  310 . The threaded rod  250  is confined within a movement area by two shoulders at the distal end. As described in FIG. 2, the threaded rod  250  is inserted through the housing  210  via two holes, one hole near the gear assembly  260  and one hole at the distal end of the threaded rod  250 . An inside shoulder  342  and an outside shoulder  244  are glued to the threaded rod  250  at the distal end. The inside and outside shoulders  342  and  344  are located inside and outside, respectively, the housing  210  to secure the rotational movement of the threaded rod  250 . Typically, the inside and outside shoulders  342  and  344  are made of a durable material such as nylon. 
     The gear assembly  260  includes first and second gears  350  and  355 . The first gear  350  is connected to the motor  270  and has a number of teeth. The first gear  350  rotates in a direction according to the motor  270 . The first gear  350  rotates in a first rotational direction when the motor  170  is energized by the control circuit in the first control action to cause the roller assembly move linearly from the first end to the second end. The first gear  350  rotates in the second rotational direction when the motor  170  is energized by the control circuit in the second control action to cause the roller assembly move linearly in the reverse direction from the second end to the first end. The second gear  355  has a number of teeth configured to fit the first plurality of teeth of the first gear. The second gear  355  rotates in the second and first rotational directions when the first gear  350  rotates in the first and second, respectively, rotational directions. In other words, the second gear  355  rotates in the opposite or reverse direction with respect to the first gear  350 . Typically, the first and second gears  350  and  355  are spur gears. The number of teeth for the first gear  350  is typically less than that of the second gear  355 . In one embodiment, the ratio between the numbers of teeth of the two gears ranges from 2 to 10. 
     The activator assembly  265  shown in FIG. 2 may include a button  360  with connection to a control circuit  370  on the control circuit board  280  (FIG.  2 ). The button  360  may be a momentary switch so that when it is pressed, it forms a connection to the control circuit  370  and the motor  270  is energized causing the gear assembly  260  to rotate. The power may be applied with a predetermined duration so that the motor is energized for a short period. In this short period, the gear assembly  260  causes a short rotation rotating the threaded rod  250 , which causes the carrier  330  to advance in a short linear distance. The roller member  310  therefore moves linearly in the short linear distance forcing a pressure on the press object  240  (FIG.  2 ). In this way, when the press object  240  is a squeeze tube such as a toothpaste tube, a predetermined amount of toothpaste is squeezed out of the tube. Alternatively, the button  360  may be a single pole single throw type of switch where connection to the control circuit is made as long as it is held closed during which time the motor  270  is energized and the roller member  310  is moved. When the button is released, the motor  270  is de-energized and the roller member  310  stops moving. In this way, the user has a direct control on how far the roller member  310  is moved. When the press unit  100  is used as a toothpaste dispenser, the user inserts the toothbrush into the activator access area  135  to push the button  360  which causes an amount of toothpaste to be squeezed out of the tube opening dropping onto the brush of the toothbrush. Other uses or applications may have similar action. For example, when the press unit  100  is used as a lotion, soap dispenser, the user may use a finger to push the button  360 . 
     The control circuit  370  is also connected to the upward and downward switches  150  and  155  shown in FIG.  1 . These switches are typically single pole single throw switches. When the upward switch  150  is pressed, power is applied continuously to the motor  270  and the threaded rod  250  turns in one direction moving the roller member  310  upward (when the unit is positioned vertically) until the upward switch  150  is released. Similarly, when the downward switch  155  is pressed, power is applied continuously to the motor  270  in the reverse direction and the threaded rod  250  turns in the other direction moving the roller member  310  downward until the downward switch  155  is released. 
     FIG. 4 is a diagram illustrating a sectional side view  400  of an electrical presser according to one embodiment of the invention. The sectional side view  400  shows a side view of the pressing unit  100  in an upright position. 
     The enclosure  110  includes the front cover  140  and a rear cover  440 . The rear cover  440  may be open for access to the battery holder  280 , the control circuit board  280 , or the motor  270 . The enclosure  110  also includes a DC jack  410  for plugging the power adapter when the unit is operated by power. The arrangement of the elements in the unit  100  may be any suitable arrangement according to the application. For example, the battery holder  280  may be located between the control circuit board  280  and the motor  270 . 
     FIG. 5 is a diagram illustrating a sectional side view of a mechanical press assembly  500  according to one embodiment of the invention. The mechanical press assembly  500  operates in a similar manner as the electrical press unit except that no electrical power is used. The mechanical press assembly  500  does not have the motor  270 , the control circuit board  280 , the battery holder  290 , and the power adapter  180 . The mechanical press assembly  500  includes the same basic elements as in the electrical press assembly such as the threaded rod  250 , the roller assembly  230 , the gear assembly  260  (except that the gear assembly  260  may include a third gear  357  as described later). In addition to these basic elements, the mechanical press assembly  500  includes a winder container  510 , a winder handle  520 , a winder gear assembly  530 , and a rotation lock assembly  540 . In the following description, the unit  100  is assumed to be in an upright position. 
     The winder container  510  contains winding coil or any winding mechanism that can be wound. The winder handle  520  is used to wind the winder container  510 . Before the unit is used, the user turns the winder handle  520  as many turns as necessary to wind the winding coil inside the winder container  510 . The winder gear assembly  530  converts the rotation of the winder handle  520  into appropriate rotation for the winder container  510 . The winder gear assembly  530  includes a first worm gear  532  and a second worm gear  534  positioned in an approximately perpendicular direction to each other. 
     When the winder handle  520  is turned, the gear assembly  260  is rotated to move the roller member  310  upward. The user stops turning the winder handle  520  when the desired location of the roller member  310  is reached. 
     The rotation lock assembly  540  locks the gear assembly  260  when in the normal state and unlocks the gear assembly when the activator  360  is activated. 
     FIG. 6 is a diagram illustrating the rotation lock assembly  540  of a mechanical press assembly according to one embodiment of the invention. 
     The rotation lock assembly  540  includes a spring  224  and a locking arm  547 . The spring  224  is fitted to the button  360 . The locking arm  547  has an L shape and is fitted to the first gear  350 . The locking arm  547  has two positions: an unlock position and a lock position. The locking arm  547  is coupled to the activator  360  and is in the unlock position when the activator  360  is activated. It is in the lock position when the activator  360  is de-activated. In the embodiment shown in FIG. 6, the locking arm  547  has a movement slot to travel from the lock position to the unlock position. The threaded rod  250  is inserted through this movement slot. Other mechanisms may also be possible. The locking arm  547  causes a locking action in the lock position when it snaps into a ridge of a third gear  357  connected on top of the second gear  355 . When locked, the gear assembly  260  does not rotate and the roller member  310  is kept stationary. When the button  360  is pushed, the locking arm  547  is moved to the unlock position slightly away from the gear tooth allowing the first gear  350  to rotate which causes the roller member  310  to moves downward. Thereafter, the spring  224  is sprung back and the locking arm  547  returns to the locking position, snapping into the next ridge of the third gear  357 , stopping the rotation and the roller member  310  is stopped. The winder container  510  is selected to provide appropriate rewinding or recoiling force so that when the locking arm  547  is in the unlock position, the first gear  350  rotates with an appropriate angular speed. 
     While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, which are apparent to persons skilled in the art to which the invention pertains are deemed to lie within the spirit and scope of the invention.