Hand tool

Abstract: A hand tool including a pair of levers (10, 12) each including a handle portion (14), a jaw portion (18) and a boss portion interconnecting the handle and jaw portions, with the levers being pivotally interconnected for normally permanently intended but relatively movable relationship. The lever sections (10, 12) are pivotally interconnected together along the boss portions for manipulation between internal and external tool operating positions. Movement between the internal and external positions is provided by work position selection structure (28) positioned on the levers, and including guiding and stopping structure for selectively moving the tool between operating positions and stopping tool movement in the proper operating position.

Description: This invention relates to a hand tool of the type used for expansion and/or contraction of differing types of deformable members, cf. GB-A-1 334 877 corresponding to the preamble of claim 1. Snap or retaining rings are either "internal" or "external". The internal type of retaining ring is used to retain elements such as bearings or shafts, within a bore. In order to install the ring it is contracted to allow it to pass into the bore, and then allowed to expand for engagement with an internal groove formed around the bore. The external type of retaining ring is used to retain elements such as bearings, gears or pulleys on shafts. An external ring normally engages an annular groove formed in a shaft to inhibit axial movement of an element mounted on the shaft. An external ring is generally installed by expanding the ring until its internal diameter is greater than the shaft diameter. The tools typically used for installing and removing internal and external rings are substantially different. A tool for installing and removing external rings, for example, must expand the rings to increase its internal diameter in order to accommodate the shaft. An internal ring installation and removal tool, however, must contract the ring in order to decrease its external diameter to enable the ring to pass through a bore. Since the function and performance required of such tools is so substantially different, retaining ring pliers are often supplied as single purpose "internal" and "external" tools. These single purpose pliers are intended for use only in installing or removing one type of retaining ring, and both types of pliers are therefore required in order to install or remove both external and internal types of retaining rings. One solution to the provision of a tool suitable for either internal or external rings has been the provision of convertible tools capable of switching between internal and external positions. These required manipulation of interconnected pieces, movement of a linkage arrangement mounted on the tool or disassembly of jaw and/or handle sections in order to accomplish the conversion. One such convertible tool, known as a universal plier, is illustrated in U.S. Patent No. 4,625,379. The tool includes a pair of pivotally interconnected handles and a pair of jaw members coupled to the handles by a latching mechanism having two transversely slidable latch members. In one position, the latch members are positioned to allow one handle member to be coupled to one jaw member and the other handle to be coupled to the other jaw member. Upon transversely sliding the latch members to a second position, the one handle is coupled to the other jaw member and the other handle is coupled to the one jaw member. While the construction of the referenced patent has enjoyed great success, it is relatively complex and it contains numerous parts which must be properly assembled and aligned during operation to provide proper functioning. In a substantially different construction, a plier is provided whereby separate pairs of jaws and handles are pivotally interconnected about a common axis and are arranged such that a pair of movable pins is adapted to alternately engage the jaw and handle pairs to shift the jaw and handle interconnections from an internal position to an external position and visa versa. An additional form of plier construction provides interconnected levers having two jaw members for simultaneous operation of the tool on internal and external retaining rings by a pair of jaws positioned for internal operation and a pair of jaws for external operation. Another convertible plier construction utilizes linkages that must be disengaged and the tool reassembled in order to change the relationship between the handles and jaws. Such a construction is cumbersome to use as it requires unneeded preparation time prior to use, and may alter the configuration of the tool such that it becomes uncomfortable to use. In addition at least some such tools have significantly different mechanical advantages in the internal and external positions. The above mentioned GB-A-1 334 877 discloses a plier tool comprising first and second levers each including a handle portion, a jaw portion, a boss portion interconnecting the handle and jaw portions, and coupling means for coupling together said levers and maintaining the boss portions in sliding, juxtaposed relationship, said coupling means including a pivot which is located at a fixed position on the first lever thereby defining a first rotation axis, and which is accommodated in an aperture in the boss portion of the second lever, the second lever being selectively movable relative to the pivot between a first working position in which the jaw portions of the two levers have a crossed relationship and a second working position in which said jaw portions have a side by side relationship, the tool including position locating means constructed such that when the tool is used in at least one of the working positions reaction forces occasioned by work operation apply position retention force to the locating means to maintain the levers in the one working position. As particularly disclosed therein, the pivot is threadedly engaged with the boss portion of the first lever and the aperture in the second lever is U-shaped to accommodate the eccentric action. The head of the pivot bears on the boss of the second lever to maintain the boss portions in sliding juxtaposed relationship. The pivot and end walls defining the slot coact to provide the locating means. The improved tool of the present invention is characterized in that the coupling means includes a work position selector coupled to the first lever by means of the pivot for relative rotation about the first rotation axis, and having means for coupling the selector to the second lever for relative rotation about a second rotation axis, said first and second rotation axes being parallel but non-coincident, whereby rotation of the selector about the second axis produces an eccentric action shifting the levers between the first and second working positions. More specifically, the present invention provides a new and improved hand tool for removing and installing internal and external retaining rings. The tool includes two levers permanently connected together which nonetheless may be easily switched between internal and external operating positions. In each embodiment reaction forces resulting from a work operation apply a position retention force to maintain the levers in a selected relationship while a work operation is performed. In a first embodiment, the tool comprises right and left operating levers pivotally interconnected together with driving structure for shifting the levers between tool operating positions. Each of the levers includes a jaw portion, a handle portion and a boss portion intermediate the jaw and handle portions. The interconnection of the levers and position of the jaw and handle portions of the levers is configured in a side by side relationship during operation of the tool in the external position. Thus, both the jaw and handle portions of the one lever operate on one side of an imaginary centre line which bisects the tool, while the jaw and handle portions of the other lever are on the other side of the centre line. When in the internal operating position, the portions are crossed such that the jaw and handle portions of the one lever operate on opposite sides of the centre line, and the jaw and handle portions of the other lever are also opposite one another relative to the centre line. In this construction, one lever and the driving structure, which comprises a driving knob, are coupled together so that the other lever moves relative to the one lever and driving knob. As a result of this construction, when the tool is in the external position, the levers are crossed. When the driving knob is manually rotated to shift the levers for operation in the internal position, the levers move to opposite sides of the centre line in side by side relationship. Because the tool is configured to provide a movable relationship between the levers for internal and external positioning, there is no requirement that discrete handle members and jaw members be selectively interconnected for being reversibly coupled to one another. The present invention instead provides that the levers are shiftable between positions. In the first embodiment, a driving knob couples the levers. The knob includes a handle portion, a lever engagement portion and a base portion disposed in a circular recess in the second lever. A pivot connects that base portion to the first lever in eccentric relationship. The base portion includes an arcuate groove which is concentric with the base portion. The second lever includes a projection which extends into the groove in a work position orientation relationship. To move the tool between external and internal positions, the handle portion of the knob is manually rotated to cause eccentric relative lever movement so that one jaw tip passes over the other. As the knob is rotated, the projection travels within the knob groove following the arcuate path of the groove over an arc of 180° or more. The levers move from one of internal and external positions to the other arriving in the other position upon the projection reaching the other end of the path. Upon contacting the end of the groove, the guiding portion acts as a stop member which stops rotation of the tool in the proper operating position. In a second embodiment of the invention, one lever is coupled with a driving knob at a driving connection. The other lever is moveable relative to the one lever and knob. The driving knob is used as in the first embodiment, in that manual rotation of the knob shifts the levers between an external position to opposite sides of the centre line in their side by side relationship and a crossed internal ring relationship. The driving knob of this embodiment comprises a drawn cup-shaped member having an annular side wall, a bottom portion supporting the knob on the one lever, and a cap member engaged with the annular wall and supported within the cup member. A pivot connection secures the knob and levers together in eccentric relationship. The second lever includes an arcuate groove for engagement with the driving connection in a work position establishing relationship, and a recessed aperture for engagement with the driving connection while providing a flush working relationship with respect to the first lever. Movement of the knob results in eccentric relative lever movement so that one jaw tip passes over the other. As the knob is rotated, the driving connection travels within the groove following the arcuate path of the groove over an arc of 180° or more. The levers thus move from one position, and arrive at the other position when the driving connection reaches the other end of the arcuate path. Upon contacting the other end of the groove, the driving connection serves as a stop member for stopping rotation of the tool in the proper operating position. When the tool of either of the embodiments is in use, reaction forces maintain the tool in at least one of its adjusted positions. With the first embodiment (see Figures 1-10), since the arcuate groove is in excess of 180° in length, the projection passes over centre and the reaction forces urge the projection against the appropriate end of the groove when in its external ring position. In the second embodiment, the pivot is forced against surfaces of the appropriate one of the stop locations in both positions. The tool of the present invention preferably includes a spring interposed between the lever handle portions for biasing the handles away from one another. Use of the spring results in the handle portions often being biased to their farthest positions. As the farthest handle positions makes it difficult to conveniently store the tool, a locking device is also provided. The device includes a locking lever arm pivotally mounted on the handle portion of the one lever. The lever arm is positioned to lockingly engage a notched portion in the boss portion of the other lever. The notched portion is configured to engage and maintain the lever arm whereby the tool remains in the locked and closed position against the bias of the spring. In the second embodiment, a raised stop limit on the other lever is also used to limit the farthest handle position when the tool is in the internal position. The stop limit engages the boss portion of the one lever to prevent handle movement past a maximum open position. These and other features and advantages of the present invention will be had by referring to the following description and claims taken in conjunction with in the accompanying drawings, in which: Figure 1 is a plan view of the plier tool of the present invention in the internal and closed position with the locking mechanism in the locked position; Figure 2 is a side elevational view of the plier tool shown in Figure 1; Figure 3 is a partial view of an alternate configuration of the tool tip of the present invention; Figure 4 is a plan view of the one lever of the plier tool of Figure 1; Figure 5 is a side elevational view of the lever shown in Figure 4; Figure 6 is a plan view of the plier tool of the present invention shown in the internal open position; Figure 7 is a plan view of the operating knob of the plier tool of the present invention on an enlarged scale; Figure 8 is a bottom view of the operating knob of Figure 7; Figure 9 is a cross-sectional view of the operating knob of Figure 7 as seen from the plane indicated by the line 9-9 of Figure 8; Figure 10 is plan view of the plier tool embodying the present invention shown in solid lines in the external closed and in phantom in external open positions; Figure 11 is plan view of a now preferred embodiment of the plier tool of the present invention in the external closed position; Figure 12 is a partial sectional view of an internal-open position stop limit taken along the line 12-12 of Figure 11; Figure 13 is a plan view of the one lever of the plier tool of Figure 11; and, Figure 14 is an enlarged partial sectional view of the driving structure of the plier tool of Figure 11. Two embodiments of the plier tool of the present invention for expanding or contracting retaining members are shown in Figures 1-10 and Figures 11-14 respectively. Parts described in connection with the second embodiment that are identical to those of the first have been identified with the same reference numeral, but with a prime and will not be separately described except to the extent required for clarity. With reference to Figures 1-10, the first embodiment of the plier tool according to the present invention, a hand tool A is adapted for expanding or contracting resilient members in an internal or external mode of operation. In the illustrated embodiment, the tool A includes a pair of lever sections 10, 12 each having a handle portion 14, covered by plastic grip covers 15, as in Figure 10. The lever sections are pivotally interconnected for normally permanent but relatively movable action about a pivot pin in the form of a threaded fastener 16. In addition to the handle portions 14, each lever section 10, 12 includes a jaw portion 18 having a forwardly projecting tip 20, and a boss portion 22. As shown in Figures 2 and 3, both tips 20 are integral with the lever section, but removable tips may be provided. The boss portion 22 is positioned intermediate the handle and jaw portions 14, 18. The lever sections 10, 12 are interconnected through their respective boss portions 22 by the pivot pin 16. The tool A is manipulated between operating modes by a shifting or driving structure 28 which permits movement of the lever sections 10, 12 between the external position, when the lever sections are in a side by side relationship, Figure 10, and the internal position, in which the lever sections are in a crossed relationship, Figures 1, 6. When the tool is in the external position as shown in Figure 10, the lever sections 10, 12 and their associated tips 20 are positioned next to one another. Squeezing the handle portions 14 causes the jaw portions 18 and tips 20 to separate and assume the open position as indicated by the phantom line tool view. The outward movement of the tips 20 to this position enables the jaw portions 18 to expand an external retaining ring. By manipulating the shifting or driving structure 28, the tool A is selectively moved to the internal mode of operation as shown in Figures 1 and 6. The tool illustrated in Figure 6 is described as being in the open position. In this position, the handles are released or biased by the spring 24, and the jaw portions and their associated tips are located away from one another. When the handle portions 14 are squeezed towards one another, the jaw portions 18 and their associated tips 20 are moved towards one another to the closed position as shown in Figure 1. Movement of the tool between these modes of operation is provided by the shifting or driving structure 28. In the embodiment of the tool shown in Figures 1-10, the shift permitting structure includes a driving knob 30. The driving knob 30, as shown in Figures 7-9, includes a base portion 32, a handle portion 34 and an engagement portion 36. The engagement portion 36 has a cylindrical surface sized for interacting engagement with walls defining a circular recess or driving aperture 37 in one lever section. The pivot 16 is interconnected with the knob base portion 32 to couple the knob 30 to the lever section 12. The attachment aperture 31, through which the pivot pin projects, is offset such that the knob 30 is connected in an eccentric relationship. The position of the attachment aperture and thus of the pivot 16 is preferably based on correct tip 22 alignment, and is obtained by appropriately sizing the radius of the engagement portion 36 and interconnecting circular recess 37. As illustrated, a spring washer 16A is positioned intermediate ahead of the pivot pin 16 and the boss portion 22 of the lever section 12 to provide stability to the tool, and also provide friction forces which prevent the knob 30 from unintentionally rotating with respect to the lever section. The distance the engagement portion projects into the aperture 37 is substantially less than or equal to the width of the lever section 10. The height of the engagement portion is necessarily limited so as to avoid interference with the lever section 12 which abuts the lever section 10 as shown in Figure 2. In the external position, reaction forces resulting from working operation of the tool, apply a position retention force maintaining the tool levers in the selected position during operation. In the internal position, a hand force and an internal retaining ring force operating on the tool result in a reaction force which biases the knob in a direction out of its proper operating position. Frictional retention forces provided by the spring washer 16A act against the reaction force to retain the knob and levers in their proper operating position. Rotation of the lever sections 10, 12 is limited by guiding engagement structure 38 on the boss portion 22 of lever section 10. The guiding engagement structure 38 limits lever rotation through operating engagement with an arcuate groove 33 in the base portion 32 of the knob 30. As shown in Figure 5, the guiding engagement structure 38 comprises a guide post 39 projecting from the boss portion of lever section 10. During manipulation of the tool between internal and external positions, the guide post 39 engages the arcuate groove 33. Movable engagement of the guide post 39 within the groove 33 is permitted, since the height and diameter of the guide post 39 are proportionate to the depth and width of the arcuate groove 33. By selectively rotating the handle portion of the knob 30, the lever section 12 moves in eccentric relation, with the guide post moving within the arcuate groove 33 until the tool is positioned in internal and external operating modes when the guide post engages the ends 40, 41 of the groove 33. The guide post 39 performs as a stop member which stops rotation of the tool in the internal or external operating position upon reaching the end of the groove corresponding to the selected position. The tool is in the internal position when the post 39 contacts the end of the groove 41, as shown in Figure 1, and is in the external position when the post 39 contacts groove end 40. The radius of the arcuate groove 33 is transverse to the central axis of the knob and extends, as shown in Figure 7, more than 180° about the perimeter of the base portion 32. By extending the groove 33 in excess of 180° about the base portion 32, eccentric movement of lever section 12 is permitted between the crossed relationship in the internal position, and the side by side relationship in the external position, whereby the jaw portion and tip of lever section 12 pass under the jaw and tip of lever section 10 without interference. Knob rotation of more than 180° is preferable in order to obtain a path of non-interfering travel between tips 20 having degrees of angulation of the type shown on the tool in Figure 2. Referring to Figures 11 to 14, an alternate and now preferred embodiment of the hand tool A′ is illustrated. As the tool A′ contains elements which are identical to the hand tool embodiment of Figures 1-10, common elements will be referred to using a prime designation. The hand tool A′ illustrated in Figure 11 includes a pair of lever sections 10′, 12′ each having a handle portion 14', covered by plastic grip covers 15′. The lever sections are pivotally interconnected about a driving connection 90, which couples the lever sections 10′, 12′ and a driving knob 30′. The driving connection 90 is in the form of a rivet joint 94. Jaw portions 18′ having tips 20′, and boss portions 22′, are also included as in the prior embodiment. The knob 30′ and lever sections 10′, 12′ are connected by the rivet joint 94 through respective aligned apertures 95, 96, and 97. The tool A′ is manipulated between positions by rotation of the driving knob 30′. The lever sections move between internal and external positions in their side-by side relationship as described with respect to the above embodiment. Movement between positions is provided by a driving structure 28′ which includes a pivot connection 100 and the driving connection 90. The pivot connection 100 interconnects the one lever section 10′ with the driving knob 30′ so that the other lever section 12′ moves relative to the one lever section and knob. The pivot and driving connections 100, 90, are best illustrated in Figure 14. The pivot connection 100 includes a rivet 101 which engages the knob 30 and one lever section 10′ through respective aligned apertures 102, 103. Both the driving and pivot connection rivets 94 and 101, which may include spring washers (not illustrated) similar to that shown in Figure 2 for providing stability to the tool, preventing unintentional tool movement, and maintaining the tool in the selected operating position. The rivet 101 includes a countersunk head portion 104 for engagement with a recessed portion 106 of the aperture 103 in the one lever section 10′, so that the one lever section 10′ and pivot connection 100 are flush with respect to the one lever section 10′, as shown in Figure 14, to avoid interference with the lever section 12' which abuts the one lever section and rivet 101. The driving knob 30' of this embodiment comprises a drawn cup-shaped member 108 having an annular side wall 110 with an outer knurled finger-engaging surface 111, a bottom portion 112 with an inner surface 114 and an outer surface 116 for engaging the one lever section 10'. The driving knob 30' also includes a cap member 118 having a plurality of finger portions 120 for engaging with the annular side wall 110 to support and secure the cap member 118 within the cup member. The one lever section 10' further includes an arcuate aperture or groove 122 for engagement with the driving connection 90 in a work position establishing relationship. Movement of the tool between positions is thus provided by manual rotation of the knob which moves the driving connection along the aperture 122 over an arc of 180° or more. By grasping the knurled surface 111 and selectively rotating the knob, the other lever section 12' moves in eccentric relation with respect to the interconnected knob 30' and one lever section 10'. The levers 10', 12' thus move from one position, and arrive at the other position when the driving connection reaches the other end of the groove. Upon contacting the other end of the groove, the rivet 94 serves as a stop member for stopping rotation of the tool in the selected operating position. The tool preferably includes a biasing spring 24, 24' which urges the handles apart. The spring 24, 24' is interconnected with the handle portions of the lever sections 10, 12 and 10', 12' by spring mounts 26, 26'. According to another feature of the invention a locking mechanism is provided for locking the handles in a closed position to inhibit their separation. As shown in Figure 1, the mechanism includes a pivotally mounted locking lever 56 secured to the handle portion 14 of the lever section 10 by a pivot 57 projecting through a lock aperture 66 in the lock lever. The lever is pivotable between lock and unlock positions, and is generally configured to minimize tool interference disengagement from the lock position upon movement or contact with other items during storage. In the illustrated embodiment, the lever 56 includes a spring engagement surface for engaging the spring when in a locked position. The lever 56 also includes a latch portion 60 engageable with a notched portion 62 formed on the periphery of the boss portion 22 of lever section 12 as shown in Figure 1. The lever further includes a finger engaging portion 64 which extends from the lever 56 and overlies the outside edge of the handle 14. The finger portion 64 provides for ease of manual pivoting of the lever in and out of the lock position. It should be apparent that when the handles are squeezed and the latch portion 60 is disengaged from the notch portion 62, the spring 24 pivotally biases the lever out of engagement with the lever section 12 along the spring engagement surface. According to another feature of the invention, a stop limit 130, raised from one surface of the second lever section 12', is used to limit the internal ring tool handle position to a maximum open position. As shown in Figure 12, the stop limit abuts the boss portion 22' to limit the opening of the spring biased handle portions 14' to a maximum open position. The present invention thus provides an inexpensive tool for the expansion and contraction of resilient retaining members. The tool is easily switched between the internal and external operating modes by merely manipulating the shifting or driving structure 28. The lever sections of the tool illustrated are constructed from stampings, the making of which is known by those skilled in the art. It should also be recognized that other relatively inexpensive methods of manufacture could be used to produce the disclosed tool components, such as using powdered metal technology.

Claims: A plier tool comprising; first and second levers (12, 10; 12', 10') each including a handle portion (14; 14'), a jaw portion (18; 18'), a boss portion (22; 22') interconnecting the handle and jaw portions, and coupling means for coupling together said levers and maintaining the boss portions in sliding juxtaposed relationship, said coupling means including a pivot (16; 90) which is located at a fixed position on the first lever (12, 12'), thereby defining a first rotation axis, and which is accommodated in an aperture (37, 122) in the boss portion of the second lever, the second lever (10, 10') being selectively movable relative to the pivot (16; 90) between a first working position in which the jaw portions (18; 18') of the two levers (12, 10; 12', 10') have a crossed relationship and a second working position in which said jaw portions have a side by side relationship, the tool including position locating means (33; 122) constructed such that when the tool is used in at least one of the working positions reaction forces occasioned by work operation apply position retention force to the locating means (33; 122) to maintain the levers in the one working position, characterised in that the coupling means includes a work position selector (30; 30') coupled to the first lever (12, 12') by means of the pivot (16; 90) for relative rotation about the first rotation axis, and having means (36; 100) for coupling the selector to the second lever (10, 10') for relative rotation about a second rotation axis, said first and second rotation axes being parallel but non-coincident, whereby rotation of the selector (30; 30') about the second axis produces an eccentric action shifting the levers (12, 10; 12', 10') between the first and second working positions. A tool according to claim 1 wherein the said aperture (37) is circular and centred on said second axis, and the selector (30) has an engagement portion (36) including an external cylindrical surface complementally coactable with walls defining the said aperture to permit said relative rotation between the selector and the second lever. A tool according to claim 2 wherein the selector is a knob (30) comprising a handle portion (34), said engagement portion (36), and a base portion (32) between the handle and engagements portions, the engagement portion including said external cylindrical surface in sliding engagement with the walls of said aperture (37). A tool according to claim 3 wherein said base portion comprises a flange (32) extending laterally beyond said aperture (37) for maintaining said levers with their boss portions juxtaposed but relatively slidable and rotatable. A tool according to claim 3 or claim 4, wherein a guide post (39) projects from one of said second lever (10) and said knob (30), and a groove (33) is formed in the other of said second lever and said knob, said guide post and groove being operably engageable for limiting rotation between said knob and said second lever. A tool according to claim 5 wherein said groove (33) is formed in said base portion (32), and said guide post (39) projects from the boss portion (22) of said second lever. A tool according to claim any one of claims 1 to 4 wherein the selector (30, 30') and one of the levers have coactable elements (33,39,90,122) which are operably engageable for limiting rotation between said selector and said one lever. A tool according to claim 7 wherein said aperture (122) is arcuate to accommodate said eccentric action, and said pivot (90) is brought into contact with respective ends of said arcuate aperture (122) when the levers are in the first and second working positions, whereby to limit rotation of said selector relative to said second lever. A tool according to claim 8 wherein said means (100) for coupling the selector to the second lever includes a pin (101) extending along said second axis between the second lever and the selector to provide for said rotation of said selector about said second axis relative to said second lever. A tool according to claim 1 or Claim 2, wherein (a) said selector is a driving knob (30') including a finger engaging surface (111), a first knob aperture (95) and a second knob aperture (102); (b) said aperture (122) in the second lever accommodating the pivot is arcuate; (c) the boss section (22') of the second lever has a second lever aperture (103); (d) said means (100) for coupling the selector to the second lever comprises a pivot connection (101) extending between said second knob aperture (102) and said second lever aperture (103) for said rotational movement of said knob about said second axis relative to the second lever; (e) said pivot (90) extends through said first knob aperture and said arcuate aperture to said first lever. A tool according to claim 10 wherein said pivot is accommodated in an aperture (97) in said first lever. A tool according to any preceding claim wherein while the levers are normally interconnected they are nonetheless separable for repair of the tool or the like. A tool according to any preceding claim wherein said jaw portions (18, 18') include non-symmetrical tip parts (20, 20') whereby to permit one tip part to pass by the other as the levers are moved between the first and second positions.

Inventors: ANDERSON J EDWARD C, JEROMSON JR JAMES, ANDERSON, J. EDWARD C., JEROMSON JR.,JAMES
Applicants: STRIDE TOOL INC, STRIDE TOOL INC.
Application year: 1988
Main classification: B25B27
IPC codes: B25B27, B25B7