GB2227515A - Combination padlock - Google Patents

Abstract

The padlock has a housing 20, 60, a U-shaped locking bar 10 a rocker located within the housing and being engageable with a flange 11 of locking bar 10, and a slide plate 30 connected with the rocker for moving it out of engagement with the flange 11 when three number wheels 40 are set to the correct combination. When this combination is set, angular cams 34, 35, 36 extending from recesses 31, 32, 33 in the plate 30 move into recesses 411 in wheel sleeves 41 the plate 30 moving under spring 80; this moves the roper and disengages rod 54 from flange 11 to allow locking bar 10 to move to an open position under force of spring 12. The rocker has a central shaft 51 received in shaft seat 27 and a shaft of a support rod 53 of the rocker is received in an elliptical hole 38 in slide plate 30. <IMAGE>

Description

A PAD LOCK The present invention relates to a pad lock of the type which are unlocked by adjustment of preselected numbers and which are more commonly knawn as combination pad locks.

The conventional types of pad locks on the market are too numerous to mention individually, but to distinguish their structure they fall into the categories (a) number check type and (b) lock and key type steel shot lock. In researching new products, there has been developed successfully the number check pad lock, that is, to combine the advantages of the two categories of conventional locking devices, for example, those shown in US PAT 9048821 and 4444029. It is known that although the above patents disclose innovatory ideas respectfully some doubts exist as to the value of such locks when actually manufactured (1) the structure is rather complicated especially to provide a convex shaped device on a locking bar to match with a sleeve, the expense of molding would be high and the assemly will be difficult.

Meanwhile, the requirements of high precision, inferior quality and low performance in use result in an increase in costs and a decrease of competitive ability. (2) In operation of such a pad lock, the locking bar is operated directly from the number wheel which means that each number wheel should match the locking bar; once any single number fails to match with the locking bar, the body of that number wheel would prevent movement of the locking bar independently of the other number wheels.

Under such circumstances, by applying force to the locking bar the convex shaped locking device is easily damaged and the locking bar can then be pulled out. Alternatively, a majority of the parts are exposed and it is easy to damage the lock from the outside. Furthermore, the housing containing the number wheel and other parts is too thin and there are too many spaces which will allow a thief an opportunity to insert a tool in the lock to force it open.Therefore, the rate of destruction of such locks is high and the useful life time is low. (3) The complicated structure also requires the locking bar to contact and engage with the housing of every number wheel directly or indirectly and there are too many contacting and matching points required to release a snap key on opening of the lock which results in the operation becoming complicated, slow and impractical.(4) The release of the locking bar should be achieved without utilizing the force of a spring, otherwise it cannot meet the requirement of automation.

Therefore it is desirable to provide a pad lock in which the above shortcomings are substantially eliminated and to produce such a lock in a most economical and practical manner.

Accordingly, to the present invention there is provided a combination bad lock comprising a housing, a locking bar extending outwardly of the housing and being movable between locked and unlocked positions relative to the housing, rocker means locatable within the housing and being engagable with the locking bar to effect locking or unlocking thereof relative to the housing, and slide means connected with the rocker means for moving the rocker means out of engagement with the locking bar when a preset code of the combination lock is selected.

An embodiment of the present invention will now be described by way of example with referecne to the accompanying drawings, in which: Fig. 1 is a perspective view of an assembled pad lock according to the present invention; Fig. 2 is an exploded view of the component parts of the pad lock of Fig. 1; Fig. 3 illustrates the pad lock when closed; and Fig. 4 illustrates the pad lock in an open position.

Referring to the drawings, Fig. 1 shows an assembled external view of a finished pad lock of the present invention in which the lock is shown to have three number wheels installed on one lateral side of the integral lock device. Three square holes 631, 641 and 651 are provided in the cover or housing, each one opposite one of the three number wheels the value of the wheel numbers is illustrated through eachhole respectively.

Referring also to Fig. 2 there is shown an exploded view of the parts of a lock in accordance with the present invention. Locking bar 10 is the same as that of an ordinary pad lock and is of the usual Ushape. On the longer end of the locking bar is radically extending flange or a snap head 11 which has a larger outer diameter than the outer diameter of the locking bar. There are at the two lateral sides of the lower housing 20 in Fig. 2 two semi-circular grooves 21, 22 to receive, respectively, the two ends of the locking bar 10. A compression spring 12 is mounted in the bottom of the groove 21 and is used to push against snap lead 11 on the longer end of the locking bar 10.In addition, support rods or bushes 23, 24, 25 are located inside the larger space of the lower housing 20 supporting a slide plate 30, three number wheels 40, three number wheel sleeves 41 and three springs 42 for biasing the number wheel sleeves against wheels 40. Furthermore, a semi-circular surface is provided on the upper part of one lateral side of a cam adjacent one edge of the lock of the lower cover 20 and which extends downwardly to a circular recess 26 on the bottom of the lower housing 20 to define L- shaped shaft seat 27 and allow the setting of a central shaft 51 of a rocker 50.

There are also two semi-circular grooves 61, 62 on the upper housing 60 which overlie the semi-circular grooves 21,22 of the lower housing 20 to form a full circle therewith, respectively. There are thre circular holes 63, 64, 65 opposite to the three supporting rods 23, 24, 25 respectively of the lower housing 20 for receiving the rods. A support rod 66 and two parallel support rods 67 are positioned between the two circular holes 63,64 and in front of the two circular holes 64, 65 to facilitate the insertion and fixing of springs 70,71 through central fixing holes thereof.As mentioned above there are also three square shaped holes 631, 641, 651 located adjacent the edge of the external side of the three circular holes 63, 64, 65 for reviewing the figures of the number wheel therethrouc:l. Locating lugs 68, 69 are provided opposite to positioning holes 28, 29 of the lower housing 20 for the fixing together the covers 20, 60 to form the lock housing.

Sliding plate 30 is one of the features in the pad lock of the present invention, and has three substantially semi-circular recesses 31, 32, 33 therein into which project three support rods 23, 24, 25 to facilitate the mounting of sleeve 41 of the number wheel 40 therein.

Angular cam faces 34, 35, 36 extend from the same point of each of the recesses 31, 32, 33 respectively for the purpose of matching with an oppositely shaped recess of a respective number wheel sleeve 41 for opening and closing the lock. Furthermore, there is an elongate recess 37 in the body of the slide plate on the lower face thereof opposite housing 20 to receive spring 80 therein. There is also an elliptical hole 38 extending through the slide plate between the semi-circular holes 31 and 32, and a support rod groove 39 is provided on the slide plate in a surface on the lower part thereon, the groove 39 extending into the of elliptical hole 38 at a height which is of the same distance as the distance between the rocker 50 and the support 52.The elliptical hole 38 receives the shaft of the support rod 53 of the rocker 50, and support rod groove 39 is provided for receiving support rod 52 therein.

In addition, the three number wheel sleeves 41 are mounted on an upper part of the semi-circular recesses of the slide plate 30 to be located in the housing by support rods 23, 24, 25 respectively. Furthermore, there is a recess 411 in the circumference of the largest diameter portion of each of the three number wheel sleeves, the size and angle of each recess 411 being exactly the same as that of the cams 34, 35, 36, respectively, of the slide plate 30. Several projections 412 are arranged to extend radially from the circumference of the shaft of each sleeve 41 to facilitate the mutual engagement and drive of tooth blocks inside each number wheel. A fine toothed cog wheel is provided concentrically with and adjacent number wheel 40 on the small axially extending shaft of the number wheel sleeve 41. An equivalent number of grooves are provided on the large shaft opposite to the toothed cog wheel to facilitate the setting of the number wheel.

The rocker is positioned on the L-shaped shaft seat 27 of the lower housing 20 by engagement with rounded end of central shaft 51.

Support rod shaft 53 at the end of the support rod 52 is located in the elliptical hole 38 of the slide plate 30. A braking rod 54 extends outwardly from one side of the central shaft 51 and is used to engage the braking head 11 of the lock bar to secure the pad lock in its locked condition when the rocker is driven by the slide plate 30.

The assembly, use and function of the above structure are described as follows: The lock is assembled in its locking condition, Fig. 3, because the cams 34, 35, 36 on the slide plate 30 and the recess 411 of the number wheel sleeves 41 are not engaged. The slide plate moves downwardly in Fig. 3 with a linear motion, the rocker 50 causes the support rod 52 to move following the movement of the slide plate 30 due to the positioning of the support rod shaft 53 in the elliptical hole 38. Simultaneously, the movement of the support rod 53 pushes the bracking rod 54 towards lock bar 10 by using the central shaft 51 as a fixed center and to rotate the rods 54 to engage a face of the braking head 11 nearest to the holes 21, 22 which locks the lock bar 10 in its closed position.Under such circumstances the locking rod 10 would be unable to move into its unlocked position because the rod 54 is preventing movement thereof.

While the number wheel 40 is adjustable to set its number (as shown in Fig. 4) the cams 34, 35, 36 on the slide plate 30 locate exactly within the recess 411 of each of the respective number wheel sleeves.

The slide plate 30 then moves upwardly under the tension of the compression spring 80 by utilizing the movement of the support rod 52 to pivot the braking rod 54 about the central shaft 51. The braking rod 54 moves backwards to disengage from the locked position of braking head 11. The freed locking rod then moves up to the open position of the lock via the force of the spring 12.

To summarize the above, the operation of the present innvention is simple, fast, accurate and practical, with the following advantages: 1) The installation of therocker results in a reduction of the number of parts and a simplification thereof. Consequently the control of quality and performance are improved. The parts and units of the rocker control device are simple and on account of the improved performance as well as the simplified structure and parts, expenditure on man power and material is reduced with a substantial decrease in the manufacturing cost. It is acceptable to both the industry and general public and would certainly be outstanding over similar known products.

2) The locking bar 10 is releasable by the rocker control device, that is the rocker is controlled by the movement of the slide plate 30 upon engagement in the recesses of the sleeve 41 of the number wheel.

The slide plate then drives the rocker to move and push the braking rod to open or close the lock. All parts are distributed uniformly for various drive actions, especially the rocker controlling device which controls the opening and closing of the lock using the braking rod to move and rotate the locking rod. This has eliminated the accustomed defect of contraction and friction. In addition, the strength of the rocker is high, causing the performance and life of the pad lock to be greatly enhanced.

3) Because the opening and closing of the lock is controlled by rocker control device, all the remainder of parts and units, other than a small part of each number wheel which has to be turned, are concealed within the body of the lock. The internal parts are difficult to reach and to be subsequently damaged from the outside, therefore providing the lock with longer life and better preformance, especially the main rocker device which is concealed securely inside the body of the lock. There is no opening to be utilized by a thief, and the assembly eliminates the defect of being damaged with a tool. Thereby a very secure locking effect for the installation of a lock is achieved.

4) On opening the lock, one is required to check the number only, the rocker controls the locking bar 10 which is forced up automatically by the spring. The operation of the lock eliminates the shortcomirg of having to pass another key before the lock is opened; the operation is simple and fast. Meanwhile, since the locking bar is pushed up automatically by the spring, it achieves the desire to meet the requirement of automation.

There has therefore been described herein a pad lock including a slide plate and a rocker, all parts are installed within the body of the lock which is formed by upper and lower housing parts in the drawings.

The operation of the lock is by mutual positioning or matching of parts, such as, the locking bar having a radially extending braking head flange, the three number wheels, the three number wheel sleeves, the spring and the reeds to achieve opening of closing the lock with a simplified and more durable structure providing an increased operating life. There are also three support shafts projecting from the lower housing and on each of which are located the number wheels the number wheel sleeves, the slid plate and a spring. A semi-circular surface is provided on one side of a cam for closing the locking bar inside the lower housing. While the semi-circular surface extends downward straight to the lower housing, it interconnects with the inner circular recess for the semi-circular shaft, which jutts out from the bottom to form an L-shaped shaft seat.

Each number wheel sleeve is provided with a recess in the outer peripheral surface of the largest outer diameter of the number wheel sleeve, for receiving a correspondingly shaped cam on the slide plate which provides three roughly semi-circular recessess into which the supporting rods of the lower housing penetrate for the insertion therein of the number wheel sleeves. Each angular cam extends from the same side of each of the semi-circular recess, their sizes and angles are the same as that of the recesses on the external peripheral surfaces of the largest outer diameter of the number wheel sleeves. The e matching of the cams and recesses of the number wheel sleeves and slide plate are used to cause movement of the slide plate for opening and closing of the lock.In addition, there is a penetrating long hole housing having a semi-circular cross-section in the underside of the slide plate to allow for the installation therein of a spring to push against the surface of the lateral wall of the lower housing and to bias the slide plate into an open position of the lock. Furthermore, an elliptical hole penetrates the slide plate between the outer two substantially semicircular holes thereof, and a support rod groove is provided where the lower part of the elliptical hole extends at the height substantially identical to the distance between the support rod and the rocker.

The rocker companies a central shaft which is located in the Lshaped shaft seat of the lower housing. A braking rod is extruded from the rocker at a point close to the lower part of the central shaft and encased and positioned in the elliptical hole of the slide plate, that is the slide plate moves and drives the support rod of the rocker upon matching with the recesses on the number wheel sleeve following rotation of the respective number wheel and the cams of the slide plate. Movement of the slide plate 30 effects movement of the braking rod 54 via the movement of the support shaft 51 centered at the central shaft to cause the braking rod to rotate and move the braking rod into engagement with the braking head to close the lock, or move the braking rod out of engagement with the breaking head to open the lock.

In brief, although the present invention provides a simple design for the improvement of the rocker control device of a pad lock, the invention brings a progressive and practical change to the pad lock design to resolve a difficult practical problem with the simplest technology.

Claims (15)

CLAIMS:

1. A combination pad lock comprising a housing, a locking bar extending outwardly of the housing and being movable between locked and unlocked positions relative to the housing, rocker means locatable within the housing and being engagable with the locking bar to effect locking or unlocking thereof relative to the housing, and slide means connected with the rocker means for moving the rocker means out of engagement with the locking bar when a preset code of the combination lock is selected.

2. A lock as claimed in claim 1, wherein the slide means and locking bar are movable in substantially parallel paths.

3. A lock as claimed in claim 1 or 2, where in the slide means is a plate having a plurality of recesses extending therethrough.

4. A lock as claimed in claim 3, including cam means projecting from the side plate into each recess.

5. A lock as claimed in claim 4, wherein the slide plate comprises three recesses.

6. A lock as claimed in any one of the preceding claims, wherein the rocker means is pivotally mounted within the housing.

7. A lock as claimed in claim 6, wherein the rocker means comprises two portions, one of which extends outwardly from the pivot and is arranged to move around the pivot to lock or unlock the locking bar and the second of which connects with the slide means to move the rocker means about the pivot upon movement of the slide means.

8. A lock as claimed in claim 7, wherein number wheels of the lock are mounted on the slide plate within the recess and are each rotatable about a respective shaft on the housing.

9. A lock as claimed in claim 8, including a sleeve wheel located within each number wheel, each sleeve wheel being set relative to one of the number wheels to determine the number of that wheel which will allow the lock to open when connected with the other selected number(s) of the other number wheel(s).

10. A lock as claimed in claim 9, wherein each sleeve wheel includes a recess in its outer peripheral surface having a shape corresponding to the shape of the cam defining the cam means of the slide plate for receiving the cam when the correct code is selected on the number wheels.

11. A lock as claimed in claim 10, wherein the slide plate is biased with its cam against the outer surface of the number wheel sleeve.

12. A lock as claimed in claim 11, wherein the locking bar includes a fixed radially extending flange on the part of the locking bar within the housing, the locking bar being engagable with the rocker means to lock the locking bar in the locked position of the pad lock.

13. A lock as claimed in claim 12, including a spring for biasing the locking bar towards the open position of the pad lock.

14. A lock as claimed in claim 13, including a spring for biasing the slide plate in the same direction as the locking bar.

15. A pad lock substantially as hereinbefore described with reference to, and as illustrated in the accompanying drawings.