Patent Publication Number: US-2011072601-A1

Title: Extendable device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/245,997, entitled “Extendable Device Using a Guide Block and Spring System to Accommodate Accessories such as Paint Rollers,” filed on Sep. 25, 2009, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     Painting apparatuses (e.g., paint rollers) are known in which a cylindrical paint brush is fitted on to a roller. The roller is rotatably connected to a handle such that a user can roll the cylindrical paint brush along a wall surface to transfer paint from the paint brush to the wall surface. In the most common design, the handle is only one to two feet long. 
     In many painting applications, it is necessary for the user to access hard-to-reach locations. For example, with interior painting of walls and the like, a user typically can not reach the ceiling of the room simply with an out-stretched arm and a typical paint roller. Accordingly, ladders and scaffolding are commonly employed in such situations. While effective, they are relatively expensive alternatives, and are relatively difficult to assemble and move about a work site. Furthermore, a dangerous situation can easily arise in which a user leans to far away from the ladder and could possibly tip over and injure him or herself. 
     Accordingly, it is often the situation that a user will employ an extension device such as an extension pole to which the paint roller can be attached. Such a device is described in U.S. Pat. No. 7,096,530, “Paint Roller With Extendable Handle,” assigned to Newell Operating Company. The described device provides a three-shaft system wherein an advancement strip assists in extending a third shaft of the device, without requiring the user to touch the third shaft. The disclosed design increases the speed of assembly of the device for use, and prevents the user from touching portions of the paint roller that could be wet and messy. 
     However, the &#39;530 patent does not address other issues that would provide improved operation. For example, the device described in the &#39;530 patent requires the user to “pull” open the device by grasping the handle and the second shaft and pulling them in opposite directions. Users with limited grip and physical strength may find it difficult to open the device prior to use. Once a user initiates opening the device, if it has required undue force, the device may overextend and “fly apart.” This results in the three shafts becoming disengaged from one another. What is needed is a way to provide added force to assist the user in extending the device, and also a way to prevent the device from coming apart should the user pull too hard when initially opening the device. 
     Further, the &#39;530 patent requires materials and manufacturing to support the design. The moving parts and assembly required increases the overall cost of the device. What is needed is a simplified design that achieves the same operational objectives, at a lower cost of material and manufacturing. 
     SUMMARY OF THE DISCLOSURE 
     This disclosure is drawn to devices, apparatuses, systems and/or methods related to extendable devices. Specifically, the disclosed devices, apparatuses, systems and/or methods relate to accessories that may require extension (e.g., paint rollers) and, more specifically, relates to extension devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. 
       In the drawings: 
         FIG. 1  depicts a simplified cross-sectional view of an extendable device in a retracted position in accordance with an example embodiment of the invention. 
         FIG. 2  depicts an exemplary cross-section view of a guide block in accordance with an example embodiment of the invention. 
         FIG. 3  depicts a simplified cross-sectional view of an extendable device in an extended position in accordance with an example embodiment of the invention. 
         FIG. 4  depicts a simplified cross-sectional view of an extendable device in a retracted position in accordance with another example embodiment of the invention. 
         FIG. 5  depicts a simplified cross-sectional view of an extendable device in an extended position in accordance with another example embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure. 
     In an example embodiment, an extendable handle for a paint applicator that includes a first shaft having a distal end and a proximal end and a second shaft with a distal end and a proximal end and which is telescopically disposed within the first shaft is provided. A guide block and spring is disposed on the first shaft and defines a curved channel. A third shaft has a distal end and a proximal end and is telescopically disposed within the second shaft. An advancement strip has a first end connected to the distal end of the first shaft and a second end connected to the proximal end of the third shaft and is disposed through the curved channel of the guide block. The advancement strip can both push and pull the third shaft relative to the second shaft. 
     In an example embodiment, as generally depicted in  FIG. 1 , an extendable device having a guide block with spring system is provided. The spring system may provide an additional thrusting force to assist in opening and extending the shafts with a reduction in pulling force required from the user. Such example embodiment may incorporate one or more “crimps” that prevent the spring force from overextending and disengaging the shafts. A example embodiment of the extendable device is described in reference to  FIGS. 1 ,  2 , and  3  below. 
     In another example alternate embodiment, the design may be modified to remove the guide block and spring. In this way, the materials contained in the device, the manufacturing and the overall cost of the device may be reduced. This example embodiment of the extendable device without the use of a guide block or spring is described in reference to  FIGS. 4 and 5 . 
       FIG. 1  shows a simplified cross-sectional view of a paint applicator  20  in accordance with a example embodiment of the invention. The paint applicator  20  includes a first handle section  22 , a second handle section  24 , an implement section  26 , and a paint roller  42 . The second handle section  24  can telescope within the first handle section  22 , and the implement section  26  can telescope within the second handle section  24  such that the implement section  26  and second handle section  24  can move from a retracted position, shown in  FIG. 1 , to an extended position, shown in  FIG. 3 . The paint applicator  20  includes a proximal end  28  and a distal end  30 . 
     In some example embodiments, the first handle section  22  includes an outer cylinder  44 . The outer cylinder  44  has a first inner surface  48  and can be a tubular member that allows for another member to be slidable within it. The outer cylinder  44  may be manufactured from any material that is durable, such as polyethylene, polypropylene, nylon, fiberglass, aluminum, steel, etc. While an outer cylinder  44  having a circular cross section is disclosed herein, it is clear that other cross sectional shapes, such as rectangular, oval, triangular, etc. are within the scope of this disclosure. 
     In some example embodiments, the second handle section  24  includes an inner cylinder  58  with a second inner surface  59  and an outer surface  61  that is disposed within and slidable relative to the outer cylinder  44 . The inner cylinder  58  can also be a tubular member that allows for another member to be slidable within its hollow core. The inner cylinder  58  can be manufactured from any material that is durable, such as polyethylene or polypropylene. While an inner cylinder  58  having a circular cross section is disclosed herein, it is clear that other cross sectional shapes, such as rectangular, oval, triangular, etc. are within the scope of this disclosure. Although it is shown in this example that the outer cylinder  44  and the inner cylinder  58  have similar shape of cross sections, this is not a limitation for the invention to function properly. It is possible to combine circular and/or other shapes of outer cylinder  44  with inner cylinder  58 . 
     In order to prevent outer cylinder  44  and inner cylinder  58  from disengaging from one another, outward end crimps  92  may be added to the proximal end of inner cylinder  58 , and inward end crimps  94  are added to the distal end of outer cylinder  44 . Thus even if inner cylinder  58  is extended to its full length, it does not disengage from outer cylinder  44 . Outward end crimps  92  and inward end crimps  94  may extend around the full perimeter, or around a partial perimeter of the respective cylinders, as long as both sets of crimps  92  and  94  align in operation to prevent disengagement. 
     Within outer cylinder  44 , a guide block  66  may be affixed to a spring  85 . First end of spring  85  is attached at the proximal end of the first inner surface  48 , and a second end of spring  85  being attached at the proximal end of the guide block  66 . The spring  85  can bias the paint applicator  20  in either the extended or retracted position, depending on user preference or application. 
     Guide block  66  may be of a shape designed to fit the first inner surface  48 , and run along the length of the first inner surface  48 , using for example a tongue and groove type of system as shown in  FIG. 2 , where handle  87  of guide block  66  compliments the first inner surface  48 . In a second example, a gear-like system is used, where the first inner surface  48  compliments guide block  66  via a ridged or toothed design (not shown). 
     In some example embodiments, guide block  66  may have a curved channel  76  formed therein that defines a pushing surface  70 . A first portion of the curved channel  76  is defined where the pushing surface  70  is opposite the pulling surface. A second portion of the curved channel  76  is defined where the pulling surface  72  is opposite from the outer cylinder  44 . In this example, the curved channel  76  has a rectangular cross section, as shown in  FIG. 2  by entrance  96  and exit  98  in guide block  66 . 
     A single locking pin  56  is located on outer surface  61  at locking hole  54 , and near the proximal end of inner cylinder  58 . Pin spring  57  urges locking pin  56  upward and outward toward first inner surface  48 . A plurality of receiver holes  62  is disposed toward the distal end of outer cylinder  44  to accommodate locking pin  56 . To move the outer cylinder  44  relative to the inner cylinder  58 , the user depresses locking pin  56  at locking hole  54 , slides inner cylinder  58  within outer cylinder  44 , and resets locking pin  56  in a new receiver hole  62 . Other alternatives to spring-locking mechanisms may be used to achieve similar results. 
     Additionally, an alternative to using pins to secure guide block  66  and spring  85  is the use of an external camming system, such as that described in Black Diamond&#39;s patent U.S. Pat. No. 5,478,117. The camming system uses a lever arm that is “flicked” open, allowing the pole to be adjusted to the desired length, and then the lever arm is closed to lock the desired length into place. The technology uses a low profile clamp disposed about the outer cylinder section to squeeze the outer cylinder and secure the cylinders in a relative fixed position. The clamp includes a lever arm pivotally attached which pivots between a closed position, in which at least a portion of the lever arm rests against the outer cylinder section to cause it to grip the inner cylinder section, and an open position, in which the lever arm is pivoted away from the cylinder sections to release the grip by the outer cylinder section. The lever arm includes a camming knuckle which, when the lever arm is pivoted to the closed position, contacts and applies a force to the camming surface of one side edge preventing slippage. 
     Furthermore, other methods could utilize screws that can be rotated into threaded receiver holes to lock the inner cylinder  58  within the outer cylinder  44 . 
     Specifications for spring  85  may depend on the size of paint applicator  20  and strength of material. The proximal end of outer cylinder  44  must be sufficiently strong to bear the compressed stored force of spring  85 , and the locking pin  56  must be sufficiently strong when engaged at each receiver hole  62  to bear the stored force of spring  85  in various states of compression. Some designs may require additional locking pins to compensate for the spring load, for example, a second locking pin could be located near the proximal end of inner cylinder  58 , but 180 degrees from locking pin  56  on outer surface  61 . 
     In some example embodiments, an optional damper  90  may be affixed to the spring  85 . The distal end of damper  90  is affixed to the proximal end of spring  85 . The proximal end of damper  90  is affixed to the first inner surface  48  at the proximal end of outer cylinder  44  along the central axis  46 . The damper used should be lightweight and capable of stabilizing, controlling, and absorbing the force of spring  85 . 
     The guide block  66  may have an outer cross section similar to that of the first inner surface  48 . The guide block  66  can include material with a reduced coefficient of friction such that the guide block can slide easily within the outer cylinder. Polymers such as Delrin® have been found to be acceptable. In this example, the guide block  66  positions the inner cylinder  58  within the outer cylinder  44  such that the inner cylinder  58  does not contact or wear against the first inner surface  48 . The guide block  66  can be manufactured in two pieces, with a portion of the curved channel  76  milled out of both halves, or the entire curved channel  76  milled out of one of the pieces. The pieces can then be mated. 
     Slidably disposed within the hollow core of the inner cylinder  58  is the implement section  26 . Affixed to the proximal end of the implement section  26  is a mounting block  80 . The mounting block  80  generally can have a cross-section similar to the hollow core of the inner cylinder  58  such that the mounting block  80  can slide smoothly within the inner cylinder  58 . 
     An advancement strip  82  may be affixed to the distal end of the first inner surface  48  at its first endpoint  84 . The advancement strip  82  is disposed along the first inner surface  48  from the distal end towards the proximal end. It then enters through the second portion of the curved channel  76  at the pulling surface  72  and travels through the curved channel  76 . The advancement strip  82  then enters through an opening  88  along the bottom surface of the proximal end of inner cylinder  58  and travels along the second inner surface  59  towards the distal end of inner cylinder  58 . The advancement strip  82  is affixed on its second endpoint  86  to the mounting block  80 . The advancement strip  82  can be affixed on its endpoints  84  and  86  by riveting, bonding, screwing, or other ways known in the art. 
     Additionally, a channel in the first inner surface  48  may be carved and may be lined with antifriction coating along the path of advancement strip  82  as it travels from the first inner surface  48 , through the curved channel  76 , and into second inner surface  59  to allow advancement strip  82  to glide easily and travel smoothly. In an alternate example, advancement strip  82  can be contained in a round or flat tube in order to provide best friction reduction and movement as it travels from between its endpoints  84  and  86 . The tube should be flexible and lightweight, such as rubber, plastic, Polyvinyl Chloride (“PVC”), or nylon. 
     The advancement strip  82  performs the dual function of both pulling and pushing the implement section  26  through the inner cylinder  58 . Thus, the advancement strip  82  should be flexible along its length such that it can curve and slide through the curved channel. The advancement strip  82  must be strong enough to pull the mounting block  80  from the extended position to the retracted position. However, the advancement strip  82  should be resistant to buckling such that it can push the mounting block  80  through the hollow core of the inner cylinder  58  from the retracted position to the extended position. 
     It has been found that strips made from spring steel such as those used in retractable tape measures has proven effective. A strip such as this can be arched along its length to provide strength against buckling. However, such a strip is also able to flatten out upon entry into the curved channel such that it can easily bend and slide through the curved channel  76 . Other strips that can both push and pull and are also resistant to buckling, such as push-pull chains, can also easily be used. In methods to reduce friction, the curved channel  76  can be lined with a material with a reduced coefficient of friction, such as Delrin® or the like. Further, the advancement strip  82  can also be covered with an anti-friction coating. 
     In use, the paint applicator  20  may be used in the first position as shown in  FIG. 1 . However, if the user needs to paint an area that cannot be reached with the paint applicator  20  in the first position, the paint applicator  20  may be placed in the second position as seen in  FIG. 3  such that the paint roller  42  is extended an additional distance. 
     To extend paint applicator  20  and adjust to the user&#39;s preferable length, the user can push and pass the locking pin  56  from the receiver holes  62  to allow relative motion between the inner cylinder  58  and the outer cylinder  44 . The user can push the second handle section  24  distally away from the first handle section  22 . The inner cylinder  58  and guide block  66  is pushed distally relative to the outer cylinder  44 . As the guide block  66  is moved towards the distal end of the outer cylinder  44 , the advancement strip  82  is forced through the curved channel  76  and is pushed through the opening  88  at the bottom surface of the proximal end of inner cylinder  58  and forced distally away from the user. Due to its resistance to buckling, the advancement strip  82  pushes the implement section  26  distally through the inner cylinder  58  as it moves along the second inner surface  59 . 
     While the second handle section  24  is being moved relative to the first handle section  22 , the distance between the first endpoint  84  of the advancement strip  82  and the pushing surface  70  decreases at the same rate the distance between the pushing surface  70  and the second endpoint  86  of the advancement strip  82  increases. Thus, for every unit of distance the second handle section  24  is moved relative to the first handle section  22 , the implement section  26  is moved one unit of distance relative to the second handle section  24  and two units of distance relative to the first handle section  22 . 
     To retract paint applicator  20 , the user may simply push the locking pin  56  from the receiver holes  62  and pulls the second handle  24  back toward the first handle  22 . As the guide block  66  is pulled proximally, the advancement strip  82  is pulled tight against the pulling surface  72 , and forced to slide through the curved channel  76  thus drawing the implement section  26  proximally relative to the second handle section  24 . 
     In some example embodiments, the guide block  66  and spring  85  may be removed from the outer cylinder  44  shown in  FIGS. 4 and 5 . If the user needs to paint an area that cannot be reached with the paint applicator  20  in the first position as shown in  FIG. 4 , the paint applicator  20  can be placed in the second position as seen in  FIG. 5   4  such that the paint roller  42  is extended an additional distance. 
     A locking pin  56 , a pin spring  57 , and receiver holes  62  is located on outer surface  61 , and near the proximal end of inner cylinder  58 . Pin spring  57  urges locking pin  56  upward and outward toward first inner surface  48 . A plurality of receiver holes  62  is disposed toward the distal end of outer cylinder  44  to accommodate locking pin  56 . To move the outer cylinder  44  relative to the inner cylinder  58 , the user depresses locking pin  56 , slides inner cylinder  58  within outer cylinder  44 , and resets locking pin  56  in a new receiver hole  62 . Other alternatives to spring locking mechanisms may be used to achieve similar results. 
     A channel  95  in the first inner surface  48  may be carved and can be further lined with anti-friction coating along the path of advancement strip  82  as it travels from the first inner surface  48  and into second inner surface  59  via opening  88  to allow advancement strip  82  to glide easily and travel smoothly from endpoints  84  to  86 . 
     To extend paint applicator  20  and adjust to the user&#39;s preferable length, the user can push and pass locking pin  56  from the receiver holes  62  to allow relative motion between the inner cylinder  58  and the outer cylinder  44 . The user can push the second handle section  24  distally away from the first handle section  22 . The inner cylinder  58  is pushed distally relative to the outer cylinder  44 , and the advancement strip  82  travels through the carved channel  95 , through the opening  88  at the bottom surface of the proximal end of inner cylinder  58  and forced distally away from the user. Due to its resistance to buckling, the advancement strip  82  pushes the implement section  26  distally through the inner cylinder  58  as it moves along the second inner surface  59 . 
     To retract paint applicator  20 , the user may simply push the locking pin  56  from the receiver holes  62  and pulls the second handle  24  back towards the first handle  22 . As second handle  24  is pulled back, the advancement strip  82  is pulled tight, and forced to slide through the carved channel  95  thus drawing the implement section  26  proximally relative to the second handle section  24 . 
     From the foregoing, one of ordinary skill in the art will appreciate that the present disclosure sets forth a paint roller that can easily extend to reach remote areas. However, one of ordinary skill in the art could readily apply the novel teachings of this disclosure to any number of situations in which an extendable device is desirable. This includes, but is not limited to, glass cleaners, booms, brooms, camera tripods, garden tools, medical devices such as IV poles, adjustable gurneys, etc. As such, the teachings of this disclosure shall not be considered to be limited to the specific examples disclosed herein, but to include all applications within the spirit and scope of the invention. 
     Following from the above description and invention summaries, it should be apparent to those of ordinary skill in the art that, while the methods and apparatuses herein described constitute exemplary embodiments of the present invention, it is to be understood that the inventions contained herein are not limited to the above precise embodiment and that changes may be made without departing from the scope of the invention. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the invention disclosed herein in order to fall within the scope of the invention, since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein.