Not applicable.
This disclosure relates to locks, and in particular, key-actuated padlocks for lockout devices.
Lockout devices, including padlocks and other lock types, are commonly used to temporarily restrict access to equipment and control instrumentation, electrical components, and fluid system components. These lockout devices can prevent incidental activation of controls during maintenance, help protect an operator from accidental contact with dangerous equipment, and/or prevent unauthorized persons from tampering with equipment or controls.
Some padlock-type devices incorporate key-actuated locking mechanisms which move blocking elements to selectively hold a movable loop-forming component (such as, for example, a wire, a curved bar, or shackle) in a closed position. The locking mechanisms commonly include multiple movable latching pieces (for example, pins, tumblers, wafers, or other movable parts) which are biased into a position to prevent the locking mechanism from being unlocked. To unlock these lockout devices, a key corresponding to the particular device must be used to engage the locking mechanism, thereby moving each of the latching pieces into a specific position to permit movement of the locking mechanism. Movement of the locking mechanism into an unlocked position clears the blocking elements and enables the loop-forming component to be moved into an open position, thereby enabling the removal or attachment of the device to one or more components.
In some padlock-type devices, the locking mechanism is connected to a cam component that is movable with the locking mechanism to selectively secure the loop-forming element. In some forms, this cam component can be driven into direct engagement with the loop-forming element, but in other forms the cam component may move blocking elements, such as ball bearings into a position for engagement with the loop-forming element. In any event, including such a cam component has often necessitated additional space to accommodate the cam, resulting in longer, larger locks. This is particularly true in padlocks with radially-actuated tumblers as part of the lock mechanism because the cam component usually adds additional axial length to the overall assembly.
Disclosed herein is a padlock of a linear lock type (that is of a type in which the key displaces tumblers coaxial with the direction of key insertion) which utilizes a locking mechanism that includes a cam configured to be integrally connected to the lock cylinder. The integral cam design can reduce the overall length of the padlock, enabling the padlock to be used in tight spaces. Among other things, in a linear lock construction, the use of the integrated cam can be used to retain a plurality of tumblers and tumbler springs in the lock cylinder eliminates the need for additional lock cylinder pieces. Further, the manner in which the cam component is attachable to the lock cylinder (for example, by snapping it on) can simplify the assembly process for the locking mechanism, thereby leading to reduced manufacturing time and costs.
According to one aspect, a padlock configured to be locked and unlocked by a key is provided. The padlock includes a lock body having an internal cavity extending axially from a key-receiving end to a shackle-receiving end opposite the key-receiving end, a shackle received by the shackle-receiving end of the lock body, and a locking mechanism received in the internal cavity of the lock body. The shackle is selectively movable between an open position in which at least one end of the shackle is separated from the lock body and a closed position in which both ends of the shackle are received in the lock body. The locking mechanism is configured to be selectively moved by the key between a locked position in which the shackle is secured in the closed position and an unlocked position in which the shackle is movable between the open position and the closed position. The locking mechanism includes a lock cylinder positioned proximate the key-receiving end of the internal cavity and configured to interface with the key, and a cam positioned at an axial end of the lock cylinder opposite the key-receiving end of the lock cylinder. The cam is integrally connected to the lock cylinder, thereby restricting axial and rotational motion of the cam with respect to the lock cylinder.
In some forms, the cam may be rigidly secured to the locking mechanism.
In some forms, the cam and/or the lock cylinder may receive a portion of the other as this may be used to integrally connect the two components together. For example, the cam and/or the lock cylinder may include an arm or arms extending axially therefrom that is/are configured to engage the other component to join them together. Such an arm or arms might include a finger configured to engage a notch or notches formed on the other receiving component. Further, the arm or arms may include an opening configured to receive a peg extending outwardly from the other one of the cam or the lock cylinder to effectuate a secure engagement of the two components. In the case of multiple arms, the arms can be positioned on varying or opposite sides of the periphery such that the other component is centrally received between the arms. It is contemplated that with this arm structure or an alternative connecting structure, the cam may be connected to the lock cylinder with a snap-fit mechanism.
In some forms, the lock cylinder may include one or more tumblers biased toward the key-receiving end of the lock body by a tumbler spring. The cam (attached to the lock cylinder) may axially constrains the tumbler spring, effectively acting as a “cap” for retaining some of the locking mechanism components within the lock cylinder.
Although it is contemplated that the component could be made from various materials, in some forms, the cam may be formed from a polymer comprising acetyl and the lock cylinder may be formed from cast zinc.
In another aspect, a locking mechanism configured for use in a lock configured to be locked and unlocked by a key is provided. The locking mechanism includes a lock cylinder with a key-receiving end configured to interface with the key and a cam positioned at an axial end of the lock cylinder opposite the key-receiving end thereof. The cam is integrally connected to the lock cylinder, thereby restricting axial and rotational motion of the cam with respect to the lock cylinder.
Again, various forms are contemplated similar to those described above in which the cam and lock cylinder are connected to one another and in which the cam effectively serves as a cap to the lock cylinder, retaining the components such as the tumblers and tumbler springs inside the lock cylinder without an additional intermediate structure.
These and still other advantages of the invention will be apparent from the detailed description and drawings. What follows is merely a description of some preferred embodiments of the present invention. To assess the full scope of the invention the claims should be looked to as these preferred embodiments are not intended to be the only embodiments within the scope of the claims.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
As used herein, unless otherwise specified or limited, “at least one of A, B, and C,” and similar other phrases, are meant to indicate A, or B, or C, or any combination of A, B, and/or C. As such, this phrase, and similar other phrases can include single or multiple instances of A, B, and/or C, and, in the case that any of A, B, and/or C indicates a category of elements, single or multiple instances of any of the elements of the categories A, B, and/or C.
The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention.
Referring first to
When received in the lock cylinder 110, the key 102 is configured to rotate the locking mechanism 108 over a range of positions that includes a locked position and an unlocked position (by virtue of aligning the tumblers to permit the rotation of the lock cylinder 110 and cam 112 within the lock body 106 as will be described in greater detail below). In the locked position, the cam 112 is shaped and configured to hold two ball bearings 118 (more generally, blocking elements) in engagement with the shackle 104, thereby inhibiting movement of the shackle 104 between the open and closed positions. In the unlocked position, the cam 112 is configured and shaped to at least partially allow the ball bearings 118 to disengage the shackle 104 so that it can freely move between the open and closed positions.
In addition to the above features, the keyway 114 is configured to provide an angular rotational stop to the key 102, limiting the range of angular positions over which the locking mechanism 108 may be rotated. The keyway 114 also configured to retain the key 102 in the lock body 106 in all but one rotational position of the range of rotational positions.
The padlock 100 also includes a cylinder cover 120 that is configured to retain the key 102 in the locking mechanism 108 and prevent the ingress of debris into the key passageway of the locking mechanism 108. The cylinder cover 120 is positioned between the locking mechanism 108 and the keyway 114 and can grip the key 102 to resist an outward ejection force acting on the key 102.
As illustrated, the shackle 104 has a generally U-shaped body including a short shaft 132 and a long shaft 134 extending from opposite ends of a curved section 136. The short shaft 132 and the long shaft 134 are substantially parallel, and each includes a latching notch 138 formed in opposite interior sides such that the latching notches 138 face each other. While the latching notch 138 on the short shaft 132 is positioned proximate the axial end thereof, the long shaft 134 extends further from the curved section 136 than the short shaft 132 and includes a retention groove 140 formed circumferentially proximate its respective axial end. Each of the latching notches 138 are formed at the same depth into the sides of the shackle 104. The retention groove 140, on the other hand, is shallower than the latching notches 138 and does not extend as far into the shackle 104. The long shaft 134 also includes a recessed face 142 extending between the retention groove 140 and the latching notch 138. The recessed face 142 has a generally planar surface formed into the inward facing side of the long shaft 134 at a depth which is less than that of the latching notches 138 and the retention grove 140. While a rigid U-shaped shackle is found in the illustrated embodiment, other shackle configurations and geometries might be employed.
Referring now to
The locking mechanism 108 includes the lock cylinder 110 which has a substantially circular cross section and axially extends from a key-receiving end 152 to a cam-attachment end 154 opposite the key-receiving end 152. A keyhole 156 is formed through the key-receiving end 152 and provides access to a forward cylinder cavity 158 formed within the lock cylinder 110. As shown in
As illustrated in
Two channels 186 are formed on opposite sides of the lock cylinder 110 to facilitate attachment of the cam 112. Each channel 186 has a generally trapezoidal shape that narrows between a channel opening 188 formed in the cam-attachment end 154 and a notch 190 cutting across the side of the lock cylinder 110. The channels 186 also includes an inclined section 192 which tapers radially outward between the channel opening 188 and a flat section 194 proximate the notch 190. The notches 190 are formed at the same depth as the channel openings 188, resulting in a steep drop-off between the surfaces of the flat sections 194 and the notches 190.
With particular reference to
At an opposite axial end of the cam 112, the bearing-engaging section 208 includes a cam spring opening 222 formed centrally relative to the circular cross section of the cam base 206. Two cam recesses—a shallow cam recess 218 and a deep cam recess 220—are formed in opposite sides of the bearing-engaging section 208. Both of the cam recesses 218, 220 define a concave outer surface that curves inward in a substantially continuous arc in-between two points on the otherwise circular profile of the bearing-engaging section 208. Although the curvature of the deep cam recess 220 is defined by an arc having the same curve radius as the curvature of the shallow recess 218, the concave curve of the deep recess 220 has a longer arc length and, therefore, extends closer to the cam spring opening 222 that the shallow recess 218.
Looking back to the lock cylinder 110, the tumbler slots 174 are each configured to receive a tumbler 228 and a tumbler spring 230 through a corresponding tumbler slot opening in the cam-attachment end 154. Each tumbler 228 is substantially planar and has a tumbler shaft 234 extending from a forward end 236 to an offset tab 238 opposite the forward end 236. The offset tab 238 extends from a corner the tumbler 228 such that it extends laterally past one side of the tumbler shaft 234, increasing the overall width of the tumbler 228. The body of each tumbler 228 tapers outward from the side of the tumbler shaft 234 to the side of the offset tab 238, providing an angled surface 240 therebetween (see
While the illustrated embodiments depicts a tumbler notch formed in at same position on all of the tumblers, it should be understood that some embodiments can have at least one tumbler with a tumbler notch that is formed closer to the forward end or the spring positioning tab that at least one of the other tumblers. For example, most locking mechanisms will have a set of tumblers with most of the tumblers having tumbler notches formed at different or varying positions along each shaft. By including tumblers with notches formed at a variety of different positions, a locking mechanism can be “coded” for use with a specific corresponding key.
As best illustrated in
When the fingers 214 are received in the notches 190, axial movement of the cam 112 relative to the lock cylinder 110 is limited to a range equal to the difference between an axial width of the notches and that of the fingers 214. Further, abutment between the coupling arms 210 and the channels 186 constrains rotational, lateral, and longitudinal (i.e., axial) motion of the cam 112 relative to the lock cylinder 110. Movement of the cam 112 relative to the lock cylinder 110 is also constrained by engagement between at least one of the tabs 252 extending from the cam-attachment end 154 of the lock cylinder and a corresponding recess 254 formed in the cylinder-attachment end 212 of the cam 112.
In some embodiments, at least one of the coupling arms can have a shape which does not correspond to the shape of the channel. For example, a coupling arm can have a linear shape that does not taper inward. A locking mechanism can also include a coupling arm and a channel that are both generally straight and without a tapering surface. At least one channel can also omit at least one of the inclined section or a flat section at the end of the inclined section. In still another embodiment, at least one channel can be omitted altogether and a coupling arm can engage the outer surface of the lock cylinder.
In still more embodiments, the cam can be coupled to the lock cylinder in a different way. For example, a mechanical fastener or an adhesive can be used to secure the cam to the locking mechanism. In another embodiment, at least one coupling arm can include an opening configured to engage a portion of the lock cylinder. A peg, a latch, of or any other projection can extend outward from the side of the lock mechanism in to engage the coupling arm. In another example, a fastener, such as a screw or a bolt, or a separate peg can extend through openings formed in the coupling arm and the cam or the lock cylinder to connect the two components. A locking mechanism can also include coupling arms, or any other coupling feature, that can be slid or twisted into engagement with the lock cylinder or the cam.
In some embodiments, at least one of coupling arms can be included on the lock cylinder and be configured to be received in a channel formed in the cam. A different number and arrangement of coupling arms and channels can also be used. In some embodiments, a cam can include one coupling arm configured the engage the lock cylinder and the lock cylinder can have two coupling arms configured to engage the cam.
Returning to
In some locking mechanisms, at least one of the tumblers can be different than at least one of the other tumblers. For example, two of the tumblers may be rectangular, one tumbler can be triangular, and the remaining tumblers can be circular. Similarly, at least one tumbler slots may be different that at least one of the other tumbler slots, and may have a shape that does or does not conform to the tumbler received therein. In another embodiment, a locking mechanism can include more or less tumblers than the illustrated embodiment. For example, a first row of tumblers can include two tumblers and a second row of tumblers can include 5 tumblers. A locking mechanism can also include more or less lateral slots or rows of tumblers. Some embodiments, for example, can include three rows of tumblers corresponding to four different lateral slots. A different locking mechanism can include a plurality of tumblers facing radially outward from the center of the lock cylinder and which are not arranged in any rows.
Notably, in the illustrated embodiment, the cylinder-attachment end 212 of the cam 112 effectively provides a “cap” on the end of the lock cylinder 110 to define a portion of the volume receiving the tumblers and/or the springs or at least provides an axial end of the volume. Thus, when the cam 112 is attached to the lock cylinder 110, the cam 112 itself provides a constraint to the tumbler springs 230, compressing the tumbler springs 230 to apply a tumbler-biasing force to the tumblers 228. When the key 102 is received in the locking mechanism 108, the tumbler-biasing force is transferred to the key as an outward ejection force against the insertion of the key.
Looking at
The movable stops 264 are configure to be inserted into the lateral slots 172 of the lock cylinder 110 so that, when the tumblers 228 in the key-out position (which is their default position), the ends of the each angled surface 272 abuts the side of the tumbler shaft 234 and the fingers 266, 268, 270 protrude out of the lateral slots 172 beyond the circumferential periphery or profile of the lock cylinder 110. However, as will be described in more detail with respect to
In embodiments of the padlock which utilize more or less lateral slots than the illustrated padlock, the locking mechanism can use more or less movable stops according to the number of lateral slots. In other embodiments, more than one movable stop can be received in at least one lateral slot. At least of movable stop can also include a different number of fingers that at least one other movable stop. For example, some locking mechanisms can have one movable stop with two fingers and two movable stops with four fingers
Referring now to
As illustrated in
As is illustrated in
Still further, it should be appreciated that these wipers 296a and 296b generally prevent the ingress of debris into the key passageway by sealing shut when no key is received through the cylinder cover 120.
Some embodiments of the cover can include a different number of wipers than the illustrated embodiment achieving the same ejection-inhibiting effect of the key within the linear lock. For example, there could be one wiper extending partially or all the way across the access slot, or four wipers, each extending from a different one of the access slots. Other embodiments can include at least one wiper that is different than at least one other wiper. For example, at least one wiper could be rigid and spring loaded. A wiper could also be configured to slide or move radially outward without axial movement, or to be compressible.
Referring to
Keeping the structural details of the locking mechanism 108 and the cylinder cover 120 in mind, details of the lock body 106 and the assembled padlock 100 can be described with reference to
In other embodiments, other methods of joining an enclosure and an enclosure base may be used. For example a different mechanical fastener or even an adhesive might be used to secure an enclosure to an enclosure base. In some embodiments, a lock body can be divided into a different set of components. At least one different side of the lock body can be detachable, or the body can be broken into halves or two or more large pieces with different proportions.
Referring to
As previously mentioned, the central chamber 332 is configured to house the locking mechanism 108 with the cylinder cover 120 and faceplate 286 attached. Looking at
When the tumblers 228 are in the key-out position, as shown in
Returning now to
While the central chamber 332 is sized to inhibit significant radial motion of the locking mechanism 108 while still permitting it to rotate, the axial length of the central chamber 332 does not exactly closely correspond to that of the locking mechanism 108. In fact, the central chamber 332 is longer than the combined lengths of the locking mechanism 108, the cylinder cover 120, and the faceplate 286, thereby potentially permitting axial movement of the locking mechanism 108. This exists for a number of production reasons, but in part is because dimensions of the various components stacked up over the linear length might potentially differ.
In order to maintain a relatively known or static key stop distance from the key stop 176 on the lock cylinder to the key-receiving axial end 342 of the central chamber 332 (see e.g., both items on
In linear locks, such as the illustrated padlock 100, the cam spring 116 is selected to provide a biasing force to maintain the key stop distance relative to the key entryway in the lock body 106, even as the key 102 is inserted into the lock cylinder 110. In such a case, the spring force provided by the cam spring 116 should exceed (in some design constructions, appreciably exceed) the collective spring force that will need to overcome the various tumbler springs 230 in order to move the tumblers 228 by the key. If this were not the case, then the attempted displacement of the tumblers 228 during insertion of the key 102 would also involve the movement of the locking mechanism 108 against the cam spring 116, which would alter the key stop distance undesirably.
It is to be appreciated that the cam spring can be selected based on different design criteria. The biasing force provided by a cam spring can be a function of at least one of spring length, spring material, or spring construction, spring type, or any other spring characteristic. Likewise, the cam spring will also likely be “preloaded” (i.e., initially in some compression) and appropriate spring modeling can be undertaken to achieve the desired applied force.
Still yet the “spring” may be differently placed in the assembly, be something other than a compression spring, and may be different in number. For example, in some embodiments, the cam spring can be configured to bias the locking mechanism 108 away from the keyway 114 and towards the interior axial end 346 thereby controllably and predictably forcing the locking mechanism against a different datum surface. In still other embodiments, instead of the compression spring, a different spring-like body providing a biasing force may be provided. For example, it is contemplated that the cylinder cover 120 could be formed from a compressible and springy material that is configured to bias the locking mechanism 108 towards the interior axial end 346 of the central chamber 332, which if appropriately dimensioned effectively replaces a compression spring with that elastically deformable polymeric body. In still further embodiments, other biasing element structural arrangements are possible. For example, some padlocks might utilize more than one biasing element, such as two, three, four or more cam springs instead of just one; however, having just one central spring does provide some benefit in that the rotation of the locking mechanism 108 then does not drag along the biasing structures. Still further, while the illustrated embodiment depicts a biasing element contacting an axial end of the locking mechanism, other biasing elements may make contact with the sides of a locking mechanism and/or be interposed between components of the locking mechanism.
Returning now to the structure of the lock body 106, the keyway 114 is formed through the enclosure base 328, thereby providing access to the central chamber 332 (and the locking mechanism 108 housed therein) through the key-receiving axial end 342. As illustrated in
In some embodiments, the keyway can have an eccentric profile shaped differently than in the illustrated embodiment. For example, the irregular notch can have at least one additional edge section that can be linear or curved. Some irregular notches can also use two or more linear edges with no curved section. A keyway can also include a key-stop edge that is formed at a different angle relative to the key slot.
Referring back to
So, in addition to the locking mechanism 108, the internal cavity 330 is also configured to receive the shackle 104 in the shackle slots 334, 336. The short shaft 132 and the long shaft 134 of the shackle can be respective received in the shallow shackle slot 334 and the deep shackle slot 336 through the shackle openings 380. The shackle slots 334, 336 are configured to allow sliding motion of the shackle 104 between an closed position where the short shaft 132 and the long shaft 134 are received in the internal cavity 330 (see, for example,
Having described the structure and some general functions of a padlock, methods of using a key to lock and unlock the padlock will now be discussed. It should be appreciated that the methods and structures for locking and unlocking the padlock, or for performing any other task or function disclosed herein, are interchangeable and are not tied to the specific embodiment of the device in which they are described. Thus, this recitation, while exemplary, should not be taken as limiting.
While the locking mechanism 108 is in the locked position as illustrated in
To move the locking mechanism 108 to the unlocked position (shown in
Exploring this key insertion and rotation process in more detail,
In the illustrated embodiment, when the locking mechanism 108 is in the locked position such that it may receive the key 102 by virtue of alignment with the keyway 114, the rotational stop 170 on the lock cylinder 110 abuts the first side 358 of the rotational stop slot 356 in the lock body 106 as illustrated in
Before receiving the key 102 through its access slot 294, central opening 300 of the cylinder cover 120 is dimensioned to inhibit debris from moving into the locking mechanism. However, as best shown in
Returning to
In addition to applying an outward ejection force on the key, the tumbler springs 230 also apply an equal and opposite force on the cylinder-attachment end 212 of the cam 112. Absent the cam spring 116, this force would urge the locking mechanism 108 away from the key-receiving axial end 342 of the central chamber 332. However, the cam spring 116 of the illustrated embodiment is configured to have a biasing force which is greater than the outward ejection force from the tumbler springs 230 to axially urge and retain the locking mechanism 108 toward the key receiving axial end 342. This enables the cam spring 116 to maintain the key stop distance at least until the key 102 is fully inserted into the locking mechanism 108 and abuts the key stop 176.
As previously discussed with reference to
As the key 102 rotates the locking mechanism 108 upon turning the key 102, the notched section 394 of the key shaft 392 rotates into the asymmetric notch 364 of the keyway 114. Rotation of the key 102 can continue until the locking mechanism 108 is in the unlocked position, as illustrated in
As the key 102 rotates, the swept edge 366 of the asymmetric notch 364 receives a shallow key notch 396 formed in the key shaft 392, and the straight side 372 of the keyway slot 362 receives a deep key notch 398 opposite the shallow key notch 396. While engaged by the key notches 396, 398, the eccentric profile of the keyway 114 provides an axial stop that permits the key 102 to be removed from the locking mechanism 108 only while the locking mechanism 108 is in the locked position with the notches otherwise straddling the material defining the keyway 114.
Looking now to
Once the bearings can move inward, the shackle 104 can be moved from the closed position into the open position by sliding away from the shackle-receiving side 382 of the lock body until the ball bearing 118 on the side of the long shaft 134 abuts the lower edge of the retention grove 140. As shown in
To re-lock the padlock 100, the shackle 104 is moved back to the closed position with the short shaft 132 in the shallow shackle slot 334 and the key 102 is turned to move the locking mechanism 108 back to the locked position. As the cam 112 rotates it pushes the ball bearings 118 back into engagement with the latching notches 138 on the shackle 104, restricting axial motion of the shackle 104. As the key 102 is extracted from the locking mechanism 108, the tumbler springs 230 bias the tumblers 228 back into their key-out positions. As the tumblers 228 move the inclined end 244 of the tumbler notches 242 push against the angle surface 272 of the movable stops 264 thereby pushing the movable stops 264 radially outward and into engagement with the finger-receiving recesses 352, thereby securing the locking mechanism 108 in the locked position once again.
It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto.