Patent Publication Number: US-2012024553-A1

Title: Implement and tool for loosening connection elements and kit comprising such implement

Description:
FIELD OF THE INVENTION 
     The present invention generally finds application in the field of handheld tools and particularly relates to a percussion implement for loosening stuck connection elements, such as threaded couplings. 
     The invention further relates to a percussion tool that incorporates such implement. 
     BACKGROUND ART 
     In general mechanics, and particularly in the automotive field, removable connection members, with threaded couplings or elements, such as nuts or bolts, but possibly of different types, such as broaches or pins are known to become often stuck. 
     In this case, any servicing or maintenance requires loosening of the elements of the pair by suitable removal techniques and tools. 
     These tools are intended to impart mechanical stresses, e.g. a torque, to one or both of the pair elements to cause uncoupling. 
     Typically, electrical tools are used for this purpose, which have a specially shaped head adapted for engagement with a matingly shaped portion of one of the two elements of the pair for imparting the required torque. 
     These solutions have a number of drawbacks, the most common of which is poor effectiveness of the tool in case of stuck couplings due to oxidized threads or partial interpenetration thereof. 
     Here, the use of rust removing solvents may be ineffective, and thus require impulsive stresses to be imparted to break the layer of oxide between the two coupled surfaces for solvent penetration. 
     Certain manual techniques, particularly used in car repairs, involve the use of two strikers on the coupling from opposite sides. 
     Particularly, one of the striker is used as an anvil and is held still in contact with a first element of the pair, whereas the other striker is used by the operator to impart the impulsive loosening stress. 
     Nevertheless, there is very little space available to the operator, which makes the operation unpractical. 
     For instance, for wheel alignment in a car, with the vehicle possibly placed on a lift, the dowel pin may happen to be stuck and require some manual action. 
     This may require the car to be further hoisted from the lift for wheel removal, which will extend the duration of the process and increase its costs. 
     DISCLOSURE OF THE INVENTION 
     The object of the present invention is to obviate the above drawbacks, by providing an implement for loosening coupled connection elements of either threaded or interlock or interference type, that is both inexpensive and simple to use. 
     A particular object of the present invention is to provide an implement for loosening connection elements that may be used even in small and hardly accessible spaces. 
     Another object of the invention is to provide an implement for loosening coupled connection elements that may be used for servicing a vehicle with two or more wheels while maintaining the vehicle in the driving position. 
     Another important object of the invention is to provide a power-operated tool for loosening threaded couplings, that can ensure a quick and simple loosening effect, even in restricted operation spaces. 
     These and other objects, as better explained hereafter, are fulfilled by an implement for loosening coupled connection elements as defined in claim  1 . 
     With the implement of the invention, a threaded coupling may be loosened even in a very small space. 
     Furthermore, in the case of a vehicle with two or more wheels, the wheels will not need to be removed. 
     In a further aspect, the invention provides a kit for loosening connection elements, which comprises an implement of the present invention, an auxiliary wrench for use with the implement, operating on one of the elements to be loosened, and possibly a percussion tool designed to be connected to the implement. 
     The wrench may be also used without the implement and the percussion tool. 
     Advantageous embodiments of the invention are defined in accordance with the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the invention will be more apparent from the detailed description of certain preferred, non-exclusive embodiments of an implement and a tool according to the invention and a wrench that is part of a loosening kit according to the invention, which are described as a non-limiting example with the help of the annexed drawings, in which: 
         FIG. 1  is an exploded perspective view of an implement of the invention; 
         FIG. 2  is a partially broken away side view of an implement of the invention; 
         FIG. 3  is a partial perspective view of an implement of the invention in a particular application; 
         FIG. 4  is a side view of a percussion tool of the invention; 
         FIG. 5  is a front view of a wrench for use in combination with an implement of the invention; 
         FIG. 6  is a cross sectional side view of the wrench of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring to the above figures, an implement for loosening coupled connection elements, generally designated by numeral  1 , may be used for loosening couplings of the type comprising at least one pair of elements coupled together, for instance, by screw, interlocking or interference connection. 
     The implement  1  may be used with nut and screw, dowel and pin assemblies, with bolts or other similar couplings in which two or more mutually coupled contact surfaces have microjunctions caused by oxidation of the outer layers or partial interpenetration thereof. 
     By way of example and without limitation, the implement  1  of the invention may find application in the field of car repairs, e.g. for loosening threaded coupling in wheel alignment procedures. 
     An example of application of the implement is shown in  FIG. 3 , in which a pair C to be loosened comprises a first externally threaded element, such as a pin P and a second internally threaded element, such as a bushing B. 
     According to the invention, the loosening implement  1  comprises a striking hammer or striker  2  that defines a longitudinal axis X and has a connecting portion  3  at one axial end, designed to be operably secured to an external percussion tool, generally designated by numeral  4  in  FIG. 4 , the latter being adapted to impart a translational or oscillatory motion to the striker in the axial direction. 
     Particularly, the connecting portion  3  may be designed to be secured to the chuck  5 , which is outlined by broken lines in  FIG. 4 . 
     The striker  2  also has a striking surface  6  at the opposite end, which is designed to face towards at least one of the elements P, B of the pair C to interact therewith and impart an impulsive stress F thereto. 
     A counteracting body  7  facing towards at least one of the elements P, B of the pair C, is provided on the side away from the striker  2  and has a counteracting abutment surface  8  longitudinally offset with respect to the striking surface  6 , and designed to contact one of the elements P, B of the coupling C to be loosened, to prevent axial translation thereof while counteracting the impulsive stress F. 
     According to a peculiar feature of the invention, retaining means  9  are provided for retention of the striker  2  to the counteracting body  7 . 
     Particularly, the retaining means  9  are designed to maintain the striking surface  6  and the abutment surface  8  longitudinally spaced from each other, at a minimum longitudinal distance d MIN , that can adequately define, between the surfaces  6  and  8 , an adequate space  10  to accommodate the pair C to be loosened. 
     In the embodiment as shown in  FIG. 3 , the pair C to be loosened, consisting of a cylindrical bushing B and a pin P, may be arranged to cause the striker  2  to exert its action on the side surface S of the bushing B. The abutment surface  8  may also be in contact with the side surface S of the bushing B. 
     Nevertheless, it shall be understood that the implement  1  of the invention may be also used with other types of couplings C, which may be also designed to be disposed in the space  10  with different orientations, for instance with the bushing B and the pin P in axial positions. 
     According to a preferred configuration of the invention, the retainer means  9  may include a longitudinally elongate tubular frame  11 , with a first hollow end portion  12  for receiving the striker  2  and a second hollow end portion  12  for receiving the counteracting body  7 . 
     The tubular frame  11  may have a substantially cylindrical shape with a side wall  14  that is closed by a transverse wall  15  at the second portion  13 . 
     At the first hollow portion  12 , the frame  11  may have a transverse opening  16  for access to the striker  2  from the outside and for attachment thereof to the tool  4 . 
     Furthermore a specially shaped opening  17  may be provided on the side wall  16  of the frame  11 , for receiving at least one of the elements P and B of the pair C to be loosened, in a substantially radial direction Y. 
     In the embodiment of the figures, the side opening  17  has substantially regular edges  18  and is formed by removing, e.g. by milling, a substantially cylindrical portion of the side wall  14  of the tubular frame  11 . 
     Nevertheless, the side opening  17  may also have an irregular shape, as shown in  FIG. 4 , for instance with lateral indents  19  for firm retention of the pair C in the space  10  between the two surfaces  6  and  8 . 
     However, openings  17  of any shape and size may be provided, possibly according to the particular type of pairs C to be loosened. 
     In a preferred, non-exclusive configuration, the striking surface  6  may be substantially flat and extend in the radial direction. The abutment surface  8  may also be substantially flat and radial, and have a radial dimension φ 1  larger than that φ 2  of the striking hammer  6 . 
     Advantageously, elastic counteracting means  20  may be provided in the tubular frame  11 , which exert their action on the counteracting body  7  to push it towards the striker  2  and oppose the retaining reaction R transmitted by the second element B of the pair C as a result of the impulsive stress F. 
     In a preferred non-limiting embodiment of the invention, the elastic counteracting means  20  may include a spiral spring  21 . 
     The spring  21  may act in a substantially axial direction and have a fixed end turn  22  abutting against the closed wall  15  of the tubular frame  11  and an opposite axially movable end turn  23  abutting against the counteracting body  7 . 
     The closed wall  15  may possibly have a central hole  24  for air to be exhausted during the translational motion of the counteracting body  7  caused by the kickback. 
     The connecting portion  3  of the striker  2  may have anchor means  25  for removably securing it to an external electrical percussion tool  4  which is adapted to impart a translational or oscillatory motion thereto in the axial direction X. 
     The anchor means  25  may include a chuck  5  known per se, adapted to be mounted to the percussion tool  4  as typically provided in electrical tools such as power-operated drills and bits. 
     The chuck  5  may be hollow and adapted to receive and retain the connecting portion  3  of the striker  2  coaxial to the tubular frame  11 . 
     A cylindrical bushing  26  may be also held within the first hollow section  12  of the frame  11  for slideably receiving the striker  2 . 
     The bushing  26  will also have the task of guiding the striker  2  along the longitudinal axis X when a translational or oscillatory motion has been imparted in the axial direction X. 
     The bushing  26  may consist of an outer cylindrical metal body  27  coaxial with an inner cylindrical body  28 . 
     The inner cylindrical body  28  may have its inner surface, designed for contact with the striker  2 , formed of a material with a relatively low coefficient of friction. For instance, the inner cylindrical body  28  may be made of Teflon or similar materials. 
     Nevertheless, these materials shall not be intended to limit the scope of the present invention, as all the components may be made of metal, plastic or composite materials, according to the mechanical resistance and light-weight requirements associated with each particular application. 
     The frame  11  may be equipped with removable fastening means  29  for removable connection thereof to the percussion tool  4 . 
     For instance, the fastening means  29  may include a clamp  30  to be closed at its ends over a longitudinal slot  31  of the frame  11  for removably fastening it to the electrical tool  4 . 
     In another aspect, the invention relates to a tool  4  for loosening threaded couplings C, which is adapted to be connected to the above described implement  1  and further comprises a head  32  susceptible of oscillating in a longitudinal direction X. 
     The tool  4  may be a known electrical tool, namely a pneumatic percussion bit, not necessarily specially designed for operation with the implement  1  of the invention. The head  32  may be equipped with the removable chuck  5 , for the implement  1  of the invention to be removably secured thereto. 
     Thus, the head  32  will transmit an oscillatory motion to the striker  2  along a longitudinal axis X, for the latter to transmit one or more impulsive stresses F to one of the elements P, B of the pair C to be loosened, placed in the space  10 . 
       FIGS. 5 and 6  shows an auxiliary wrench  33  designed for use in combination with the implement  1  for engaging one of the connection elements of the pair C to be loosened, such as the element P, to promote rotation thereof and facilitate unscrewing of the pair C. 
     The wrench  33  may be supplied in combination with the implement  1  of the invention and/or the percussion tool  4  to form a loosening kit. 
     Nevertheless, the particular features of the wrench  33 , as described below, will also allow it to be used alone, without the implement  1  and the tool  4 . 
     In other words, the loosening effect may be also obtained by the wrench  33  only. 
     The wrench has a handle  34  that allows it to be held by a user, and a gripping ring  35  that has a central seat  36  for at least partially accommodating one of the elements P to be loosened. 
     The ring  35  has a first portion  35 ′ integral with the handle  34  and a second portion  35 ″, removably secured to the first portion  35 ′ by removable anchor means, to allow the seat  36  to be opened and receive the element P to be loosened. 
     In a preferred, non-limiting embodiment of the invention, the handle  34  substantially extends along a main axis of extension L. The two ring portions  35 ′,  35 ″ are substantially symmetrical with respect to an axis transverse to the axis of extension L. 
     The two portions  35 ′,  35 ″ may be removably secured to each other by a pair of screws  37 ,  38 , bolts or similar members, which engage respective pairs of aligned holes formed on both ring portions  35 ′,  35 ″. 
     Particularly, the first ring portion  35 ′ has a pair of blind holes  39 ,  39 ′ and the second ring portion  35 ″ has a pair of through holes  40 ,  40 ′ adapted to be aligned with respective blind holes  39 ,  39 ′. 
     When the two ring portions  35 ′,  35 ″ are secured to each other, the seat  36  will be closed and define a side wall  41  suitably shaped according to the particular application for which it is intended. 
     Particularly, the shape of the side wall  41  of the seat  36  may be selected according to the cross section of the element P of the pair C to be loosened, for which the wrench  33  is designed. 
     In the illustrated embodiment, which is particularly advantageous, the side wall  41  of the seat  36  has a first substantially cylindrical axial portion  41 ′, and a second axial portion  41 ″ adjoining the first portion and having a substantially prismatic shape. 
     Particularly, the second axial portion  41 ″ has a hexagonal profile, to engage a hexagonal connection element P. 
     In operation, in order to engage the wrench  33  with one of the elements P to be loosened, the two ring portions  35 ′,  35 ″ will be released by removing the retainer means  37 ,  38  and thus access will be provided to the central seat  36 , that will be divided into two halves  36 ′,  36 ″. 
     Then, the element P to be loosened will be placed in the half  36 ′ of the seat  36  defined by the first ring portion  35 ′. Now, the second portion  35 ″ will be mounted thereupon, to form the seat  36  with the element P to be loosened is enclosed therein. Finally, the two ring portions  35 ′,  35 ″ will be secured to each other, allowing the required unscrewing torque to be exerted on the element P to be loosened. 
     If the wrench  33  is to be combined with the implement  1 , it may be used at the same time as the implement  1 , thereby allowing the torque to be imparted at the same time as the impulsive stress F. 
     However, the wrench  33  may be also used before or after using the implement  1 . 
     It shall be reminded that the wrench  33  may be also used without the implement  1  and/or the percussion tool  4  and will not necessarily be part of a kit according to the present invention. 
     In this case, the wrench  33  will maintain its advantages, namely the ability of forming a closed seat  36  for the element P to be loosened, and thus of exerting a higher torque and preventing disengagement of the element P to be loosened, but will still be able to be opened, and thus to be used even when the elements to be loosened are hardly accessible. 
     The implement, tool, wrench and kit of the invention are susceptible to a number of changes or variants, within the inventive concept disclosed in the appended claims. All the details thereof may be replaced by other technically equivalent parts, and the materials may vary depending on different needs, without departure from the scope of the invention. 
     While the implement, tool, wrench and kit have been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.