Abstract:
A tactile handle integrated scale that measures the weight of an attached element and provides tactile output. The handle with an integrated scale can be attached onto luggage, a briefcase, a backpack, or other liftable objects. The scale provides tactile output and a tactile gauge, so that users can ascertain the weight using touch only and without requiring visual inspection of the gauge. A switch may be provided to enable or disable the measurement feature of the handle. The handle may be attached to the liftable object using linkages that permit rotation of the object relative to the handle.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     One or more embodiments setting forth the ideas described throughout this disclosure pertain to the field of weight measurement devices. More particularly, but not by way of limitation, one or more aspects of the disclosure enable a tactile handle integrated scale. Such a handle with an integrated scale may be attached to luggage, a backpack, a container, or any other object that can be lifted, pulled, or transported, and provide a weight measurement when the attached object is lifted by the handle. One or more embodiments employ tactile outputs so that weight values can be determined using touch. 
     2. Description of the Related Art 
     Straps or handles with integrated scales are well-known in the art. For example, Laniado in US Patent Publication US 2007/0056779 teaches a backpack with shoulder straps having integrated scales. These scales use torsion springs coupled to a moveable weight indicator with weight gauges coupled to the shoulder straps. Similarly Siwak in U.S. Pat. No. 7,281,615 teaches a scale integrated into a luggage handle, which uses coil springs to measure the weight of the luggage. 
     Mechanisms known in the art for integrating weight measurement devices into handles have used visual outputs to indicate the measured weight. For example, Laniado teaches shoulder straps with scales that display measured weight using a pointer and a set of markers for the weight, much like an analog scale. Laniado also comments that output may be via a digital display. Siwak also teaches scales with analog output, using for example colored bands, or with digital output. In all known mechanisms for handle integrated scales, the output of the measurement is interpreted visually. A user must examine the scale and the gauge to determine the weight of the item attached to the handle. 
     A limitation of existing handle integrated scales is that they are not usable by people with vision impairments who are unable to easily read the scale output. Users with adequate vision may also find it inconvenient in some cases to have to examine the scale to determine the weight, for example in dark conditions. 
     For at least the limitations described above there is a need for a tactile handle integrated scale with tactile output so that users can determine the weight without looking at a visual output. 
     BRIEF SUMMARY OF THE INVENTION 
     At a high-level the disclosure set forth herein is directed to a tactile handle integrated scale. Utilizing this system enables a user to weigh an object that is attached to the tactile handle integrated scale by measuring the force exerted on the scale as it is lifted by the handle. The handle provides tactile measurements that can be discerned by the user with the sense of touch and for example without looking at the scale. In addition, one or more embodiments enables the scale feature to be locked, so that the handle does not display or output any measurement values. 
     The tactile handle integrated scale is meant to provide the user with a convenient method of weighing an object without the need to attach a separate weighing device or visual inspection thereof. As a result of the scale being handle integrated, the user may assess the weight at any moment. As in the case with personal luggage, one may not have access to a scale when it is necessary, such as on vacation. Because of the stringent weight limits set on items such as, but not limited to, personal luggage, one must be able to weigh one&#39;s own items or potentially pay for excess weight fees. 
     The tactile handle integrated scale may be attached to any object that requires knowledge of its weight. The tactile handle integrated scale may be attached at the natural spot or spots where a traditional handle would be attached. In addition to adding the convenience of allowing weight measurements, the tactile handle integrated scale will allow the user to carry and transport the object more easily. 
     In one or more embodiments the tactile handle integrated scale may be attached at two ends to the liftable element. These two ends define an axis that extends between them, called the longitudinal axis of the handle. A vertical axis extends from the liftable element towards the handle, and a transverse axis is perpendicular to the longitudinal axis and the vertical axis. In some embodiments the handle may attach at more than two or fewer than two points to the liftable element. 
     Embodiments of the invention incorporate a force detection element into the handle to provide an integrated scale. This force detection element may include mechanisms such as extension or compression springs, elastic cords or bands, torsion springs, gas or liquid pistons, piezoelectric sensors, or any other devices that can measure an attached weight. The force detection element has one or more measurable physical properties that change as a function of the force on the element. Such properties may include, for example, length, width, size, shape, temperature, electrical resistance, or any other property affected by force. The force detector is coupled to a force indicator that indicates the amount of force detected. This force indicator includes one or more tactile features so that the position and force reading of the force indicator can be determined using touch. Such features may include for example size, shape, texture, elasticity, or any combination of these elements. For example, in some embodiments the tactile force indicator may include a protrusion that extends out of the handle, whose location can be felt easily by the user, for example without requiring that the user obtain scale values visually. 
     One or more embodiments may include a gauge integrated into the handle with one or more tactile level indicators. Each level indicator corresponds to a particular value or range of the detected force. The level indicators may include tactile elements that allow a user to determine the level using touch. These tactile features may include for example the shape, size, texture, or elasticity of the level indicator. For example, a tactile level indicator may include a recessed slot or raised ridge on the handle whose length or size is proportional to the weight at that level. Tactile level indicators in some embodiments may include braille symbols or similar markings that let users read the indicator using touch. Braille symbols or similar markings may also be provided on the tactile force indicator. 
     One or more embodiments may include features that support the load of the attached weight once it reaches a threshold, to prevent an excessive weight from being applied to the force detector. For example, embodiments may incorporate a limiting surface into the handle that the force indicator contacts at a threshold weight, preventing further movement of the force indicator and supporting the load of the attached object. Such features may also provide a safety mechanism to support the attached object if the force detector breaks. 
     In one or more embodiments of the invention, the force detection element may be internal to the handle. For example, a handle may have an outer housing with a compression or extension spring inside the housing. Placing the force detection element inside the handle may provide potentially greater compactness, reliability and user safety. 
     In one or more embodiments, the handle may include a moveable switch that can enable or disable measurement of the attached weight. When the switch is in the measurement-on position, the attached load is applied to the force detection element, and the weight is reported by the force indicator. When the switch is in the measurement-off position, e.g., the locked position, the force detection element is uncoupled from the load, and a different load-bearing mechanism is switched into place. In some embodiments the moveable switch may have common parts with the force detection element. 
     In one or more embodiments of the invention, the tactile handle integrated scale may be attached to the liftable object using linkages that support rotation around one or more axes. For example, two ends of the handle may be attached to the object with revolute joints whose long axes lie along either the longitudinal or transverse axis of the handle. Some embodiments may use linkages that permit rotation around multiple axes. In one or more embodiments, a dual rotation linkage may be used for one end of the handle that includes a cylindrical bolt fitting in a through-hole along the longitudinal axis, providing for rotation of the handle around this longitudinal axis. In such a dual-rotation linkage, the through-hole in one or more embodiments may be wider at the ends of the hole than in the middle, allowing the handle to tilt partially around the transverse axis as well. This dual rotation linkage assists with force measurement for embodiments where one end of the handle needs to expand or contract as a function of the weight of the attached object, since this expansion or contraction naturally tilts the attached object relative to the handle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of the ideas conveyed through this disclosure will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
         FIG. 1  illustrates a perspective view of an embodiment of a tactile handle integrated scale attached to an object such as a suitcase. 
         FIG. 2  illustrates various tactile elements of an embodiment of the invention, specifically a tactile force indicator and tactile level indictors on the handle. 
         FIG. 3  shows an exploded view of the force detection element of the embodiment of  FIG. 2  and mechanisms that couple the force detection element to the handle. 
         FIG. 4  illustrates an embodiment of the invention with a moveable switch that can turn on or off the force detection feature, shown here in the detection off or “locked” position. 
         FIG. 5  illustrates details of an embodiment that can lock out force detection, shown as a cross section and exploded view of the portion of the handle that disables force detection. 
         FIG. 6  illustrates an embodiment of the invention that allows the handle to rotate relative to the object it is carrying. 
         FIG. 7  illustrates a close up sectional view of an embodiment of the invention that allows the handle to rotate in two different axes relative to the liftable object. 
     
    
    
     DETAILED DESCRIPTION 
     A tactile handle integrated scale will now be described. In the following exemplary description numerous specific details are set forth in order to provide a more thorough understanding of the ideas described throughout this specification. It will be apparent, however, to an artisan of ordinary skill that embodiments of ideas described herein may be practiced without incorporating all aspects of the specific details described herein. In other instances, specific aspects well known to those of ordinary skill in the art have not been described in detail so as not to obscure the disclosure. Readers should note that although examples of the innovative concepts are set forth throughout this disclosure, the claims, and the full scope of any equivalents, are what define the invention. 
       FIG. 1  illustrates a perspective view of an embodiment of the invention with tactile handle integrated scale  101 . Handle  101  is attached to liftable element  102 . Embodiments of the invention may be attached to any type of object, including for example luggage, backpacks, briefcases, carrying containers, sports equipment, or more generally any object that can be lifted, transported, pulled, pushed, moved, stretched, or weighed. In the embodiment shown, handle  101  attaches at two sides to liftable element  102 . In the embodiment shown, the left side of handle  101  has a left U-shaped mounting block  103 , and the right side of handle  101  has a right U-shaped mounting block  104 ; these U-shaped mounting blocks are attached to the liftable element. Other embodiments may attach to the liftable element at more than two sides, or at only one side, and they may use other shapes, sizes, and configurations for mounting blocks. Handle  101  may include para-aramid synthetic fiber, such as KEVLAR®, leather, plastic, polyester, polyvinyl chloride “PVC”, nylon, styrene, rubber, steel, steel composite, carbon fiber, aluminum, any metals or alloys, or any other object or material that may support liftable element  102  for example. 
     The embodiment illustrated in  FIG. 1  is shown along with three axes for illustrative purposes: a longitudinal axis  110  that extends between the two mounting blocks  103  and  104  of the handle  101 , a vertical axis  111  that extends from the liftable element  102  towards the handle  101 , and a transverse axis  112  that is perpendicular to axes  110  and  111 . 
       FIG. 2  shows a detailed view of handle  101  of the embodiment illustrated in  FIG. 1 . Incorporated into handle  101  is force detection element  210 , which in this embodiment is a compression spring housed inside the handle body. Other embodiments may use other types of force detection elements such as elastic bands, torsion springs, gas or liquid pistons, piezoelectric pressure sensors, or any other mechanism that can sense an attached weight using a measurable physical property. Coupled to force detection element  210  is tactile force indicator  201 . In the embodiment shown in  FIG. 2 , the force indicator  201  may move vertically up and down handle  101  in the vertical groove on the side of the handle as the weight of the attached object varies. Force indicator  201  is tactile because it is of a shape and size that it can be detected by touch. In the embodiment shown, tactile force indicator  201  includes a protrusion that extends from the handle; it is therefore simple for a user to feel the position of the indicator  201  and to locate this position by sliding a hand or finger along the handle. Other embodiments may use other sizes and shapes of force indicators. In some embodiments the force indicator  201  may have a texture that is different from the surrounding handle material to assist with tactile location of the indicator. For example, the force indicator may have a rough surface to distinguish it from a smooth surface of the rest of the handle. In other embodiments the force indicator  201  may have a different elasticity from the surrounding handle material. For example, the force indicator may consist of a pliable rubber material, while the surrounding handle material may be metal. In some embodiments the force indicator  201  may include braille symbols that identify it; for example the force indicator may be engraved with symbols indicating “W” or “weight” or any other label or symbol. In one or more embodiments, the force indicator may move vertically as shown, or with modifications, horizontally, diagonally, rotationally, in or out, or in any direction or directions in response to changes in weight, for example by changing the shape of the channel in which force indicator  201  travels. In some embodiments the tactile force indicator may remain in the same position but it may change its size, shape, texture or elasticity in response to changes in weight. 
     The embodiment shown in  FIG. 2  also has tactile level indicators that form a gauge for the measured weight of the liftable element. In  FIG. 2  the tactile level indicators are the slots  202 ,  203 ,  204 , and  205  on the handle. These level indicators are tactile because they can be sensed with touch. In the embodiment shown the sensing of the level indicators uses the recessed shape of the indicators relative to the surface of the handle. Other embodiments may use ridges instead of slots, or combinations of ridges and slots, or more generally may use any shapes or sizes or textures that can be felt by the user. Embodiments may use any number of tactile level indicators. For example, one or more embodiments may use only a single level indicator that indicates that the weight is excessive relative to some standard or regulation. In the embodiment shown in  FIG. 2 , the slots  202 ,  203 ,  204 , and  205  each have a different width. The different widths of these force indicators help the user identify the level using relative size, which can be detected using touch. Other embodiments may use other methods to indicate the relative weight associated with each different level indicator. For example, level indicators may have different sizes, shapes, textures, or elasticities. In one or more embodiments level indicators may include braille symbols for the weight associated with the indicator. In some embodiments the level indicators may be identical, and the user may determine the level by counting the number of indicators between the start of the gauge and the force indicator, using touch. 
     In the embodiment shown in  FIG. 2 , force indicator  201  moves down handle  101  inside the vertical slot adjacent to level indicators  202 ,  203 ,  204 , and  205 . As the weight of the attached object increases, the force indicator  201  moves closer to the bottom of the slot as force is applied upward via the handle. At a limiting weight, force indicator  201  will come in contact with the bottom surface  206  of the vertical slot. At this limiting weight and at higher weights the load of the attached liftable element will be borne by the contact force between force indicator  201  and the surface  206 , rather than by the force detector. This mechanism therefore limits the maximum weight applied to the force detector. It has the additional benefit of providing a safety mechanism in the event that the force detector breaks or comes out of position. For example, in the embodiment shown in  FIG. 2 , if the force detector spring breaks, the force indicator  201  will fall to the bottom surface  206  and the contact force will hold the load. Other embodiments may use different mechanisms to limit the maximum force applied to the force detector, and to provide a safety mechanism if the force detector breaks. For example, in some embodiments there may be other surfaces, such as surfaces internal to the handle, that limit the motion of the force indicator instead of or in addition to the bottom surface  206  of the vertical slot. Other embodiments may use safety straps or cables with a maximum extension that are attached between the handle and the liftable element; such safety straps or cables may be configured to not impede the extension of the force detector until the maximum extension is reached. One or more embodiments may use a combination of methods to limit the maximum force on the force detector and to provide integrity and safety if the force detector breaks. 
       FIG. 3  illustrates a detailed, exploded view of components of the force detector and the handle from the embodiment shown in  FIG. 2 . Only the right side of the handle  101  is shown. The right side of handle  101  includes a top handle section, bottom handle section  302 , and right mounting block  104 . Bottom handle section  302  is attached to mounting block  104  using bolts  304  and  305 , and mounting block  104  is attached to the liftable element. Force detector  210  in the embodiment shown is a coiled spring that compresses under load from the liftable element. Other embodiments may use other mechanisms for force detection, such as for example extension springs, torsion springs, elastic bands, gas or liquid pistons, or purely electronic devices. Spring  210  is compressed between annular element  322  at the top of the spring, and spring retention plate  310  at the bottom of the spring. Attached to annular element  322  is force indicator  201 . Spring retention plate  310  is attached to the top section of handle  101  using bolts  311 ,  312 , and  313 . Annular element  322  is not rigidly attached to the top handle section; instead it is coupled to bottom handle section  302 , and hence to the liftable element. The coupling of  322  to  302  is via bolt  320  which is inserted through the bottom of  302 , and which extends upwards into the upper handle section and through the annular element  322 , terminated in nut  321 . The weight of the attached liftable element therefore pulls downward on bottom handle section  302 , which pulls bolt  320  downwards and in turn pulls annular element  322  downwards. Spring  210  is therefore compressed since the spring retention plate  310  keeps the spring inside the upper handle section of handle  101 . 
     The embodiment illustrated in  FIG. 3  uses a force detector  210  that is internal to the handle, and specifically that is internal to the upper section of handle  101 . This design offers a benefit that the spring mechanism is isolated from the user. Such a design may offer greater compactness, and it may offer a safety benefit in that a broken spring is not a direct risk to the user. Other embodiments may have force detectors that are external to the handle, or that form a continuous part of the handle. 
     One or more embodiments of the invention may include a moveable switch that may enable or disable the weight measurement feature of the handle. One such embodiment is illustrated in  FIG. 4 . In this embodiment the tactile force indicator  201  can be rotated 90 degrees from an orientation in the transverse axis of the handle to an orientation in the longitudinal axis of the handle.  FIG. 4  shows force indicator  201  after such a rotation. When rotated to the longitudinal axis, force indicator  201  is in contact with surface  401  of the handle; it is therefore unable to move downward. Contact force between  201  and  401  supports the liftable object in this position, and the force detector is decoupled from the load. This rotated position is therefore a measurement-off position that disables the weight measurement feature. When the force indicator  201  is rotated back to the transverse axis, as is shown for example in  FIG. 2 , the force indicator is free to move vertically and it is in a measurement-on position. 
     In the embodiment shown in  FIG. 4 , the force indicator and the moveable switch are common parts. Other embodiments may decouple these functions and have a force indicator and a separate moveable switch to enable or disable weight measurement. 
       FIG. 5  illustrates a detailed exploded view of the force indicator and the handle of the embodiment of  FIG. 4 , with the handle shown in a sectioned view along the horizontal plane. This view illustrates that when the force indicator  201  is rotated to the measurement-off position, e.g., the locked position, multiple surfaces of the annular element attached to  201  are placed into contact with inner surfaces of the handle. In particular, section  501  of the annular element contacts inner surface  503  of the handle, and section  502  of the annular element contacts inner surface  504  of the handle. In addition the force indicator  201  contacts surface  401  of the handle. The particular shape and design of this embodiment therefore provides a strong resistance force against downward movement when in the measurement-off position, due to the contact of multiple surfaces. The shape of the annular element in this embodiment has surfaces at different outer diameters, allowing it to provide a locking function when rotated in one orientation, but to travel freely down the handle when rotated in another orientation. 
       FIG. 6  illustrates an embodiment in which the handle can rotate along the longitudinal axis relative to the liftable element. For example, one or more embodiments of the invention provide rotating linkages between the handle and the liftable element, so that the orientation of the handle relative to the liftable element may be changed. In this embodiment the handle  101  has a top section, and two bottom mounting blocks  103  and  104 . Mounting blocks  103  and  104  are coupled to the liftable element (which is not shown). The mounting blocks have through-holes along the longitudinal axis  110 . In the embodiment shown, bolt  610  couples mounting block  103  to the top section of handle  101 , and bolt  611  couples mounting block  104  to top section of handle  101 . If the through-holes in mounting blocks  103  and  104  are sufficiently wide and smooth, top handle element will be free to rotate around longitudinal axis  110 . 
     In other embodiments of the invention, the handle may include rotating linkages that permit free rotation of the top handle section along the transverse axis  112 . For example, in one or more embodiments the orientation of mounting blocks  103  and  104  may be rotated by 90 degrees, so that bolts  610  and  611  are orientated along the transverse axis. These linkages would permit free rotation around the transverse axis, provided that the design of the top handle does not over constrain the rotation. For example, in one or more embodiments the top handle may have the form of a parallelogram with free rotation along each vertex; such embodiments would permit top handle elements to rotate in the transverse axis. 
     One or more embodiments may include dual rotation linkages between the top handle element and one or more of the bottom handle elements. These dual rotation linkages may permit free rotation of the top handle element relative to the bottom handle around multiple axes, for example around both of the longitudinal and transverse axes. Embodiments may employ any of a number of known linkages that provide rotation along multiple axes, such as universal joint linkages, combinations of linkages in series, or ball and socket linkages. Some embodiments may also employ linkages that permit rotation around the vertical axis, or linkages that provide rotation around any number or combination of axes. 
       FIG. 7  illustrates an embodiment of the invention with a dual rotation linkage using a single bolt with a non-uniform bolt hole.  FIG. 7  is a sectional view of the left side of handle  101  and of left mounting block  103 , with a section taken along the vertical plane defined by longitudinal axis  110  and vertical axis  111 . Transverse axis  112  is not shown as it is perpendicular to the plane of  FIG. 7 . Cylindrical bolt  610  (as shown in  FIG. 6 , but omitted from the sectional view of  FIG. 7 ) passes through a bolt hole to couple  103  to the top section of  101 . The top handle section can rotate freely around the longitudinal axis if the bolt hole is sufficiently wide that bolt  610  does not bind in the hole. The diameter of the bolt hole is not uniform; it is wider on the edges than in the center. In the embodiment shown, left hole diameter  703  and right hole diameter  704  are both greater than middle hole diameter  702 . These additional gaps in the hole at the ends allow the top section of the handle to tilt around the transverse axis to the extent provided by the wider diameters of the bolt hole at the ends. This tilting around the transverse axis offers a benefit that the top handle can remain in a stationary orientation as the bottom handle and the liftable element rotate. In some embodiments the expansion or contraction of the force detector causes the length of one side of the handle to grow or shrink relative to the other side of the handle, which causes the liftable element to tilt relative to the top handle. An embodiment with a linkage that provides for relative rotation around for example the transverse axis allows for such a change in the relative length of the two sides of the handle. Without such a mechanism it is possible that the handle would be overconstrained relative to the liftable element, making it difficult or impossible for the force detector to expand or contract. 
     While the ideas herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.