Throw lock assemblies, throw bolt assemblies, and methods for assembling and using same

Abstract

A lock assembly comprising a throw bolt, a bolt holder and a bolt keeper. The bolt comprises a cutting barrier and a bolt casing, the bolt casing being more corrosion-resistant than the cutting barrier, and the cutting barrier being more abrasion-resistant that the bolt casing. When assembled, the cutting barrier will be enclosed within the bolt casing.

Claims

1. A throw lock assembly to lock a gateway, comprising: a throw bolt, a bolt holder and a bolt keeper, and the throw bolt comprising a cutting barrier and a bolt casing to house the cutting barrier, the cutting barrier being harder than the bolt casing, and the bolt casing being more corrosion-resistant than the cutting barrier; configured such that when arranged as in use, the throw bolt will be moveably coupled to the bolt holder, and is configured to be moved between a locking position and a non-locking position, in which in the locking position, a throw portion of the throw bolt will project from the bolt holder and extend into the bolt keeper, and in the non-locking position, the throw bolt will be retracted from the bolt keeper; and in which the throw portion of the throw bolt will include at least a portion of the cutting barrier, and an entirety of said portion of the cutting barrier in the throw portion will be shielded; in which the throw bolt comprises a spacer member housed within the bolt casing, arranged between the cutting barrier and a side wall of the bolt casing; in which the spacer member comprises material having lower hardness than the cutting barrier; and the throw lock assembly comprising: a drive mechanism to move the throw bolt in use between the non-locking and locking positions, responsive to an engagement member of the drive mechanism being inserted into a recess provided in the throw bolt and applying a force to the throw bolt; and in which the spacer member is configured such that the recess is formed through the side wall of the bolt casing and into the spacer member, without passing through the spacer member.

2. The throw lock assembly as claimed in claim 1, configured such that when assembled as in use, and the throw bolt is in the locking position, the cutting barrier will extend at least from an end of the bolt holder to at least a nearest end of the bolt keeper.

3. The throw lock assembly as claimed in claim 1, in which the cutting barrier comprises material having Rockwell C hardness of at least 55 HRc.

4. The throw lock assembly as claimed in claim 1, in which the cutting barrier comprises material consisting of one of the following: hardened steel, carbon steel, and cast iron.

5. The throw lock assembly as claimed in claim 1, in which the bolt casing comprises at least one of: a plurality of cooperatively configured casing members; and stainless steel.

6. The throw lock assembly as claimed in claim 1, in which the bolt casing comprises: a casing body and a cover plate; configured such that the casing body defines a cavity to accommodate the cutting barrier, and the cover plate joined to the casing body to enclose the cutting barrier within the cavity.

7. The throw lock assembly as claimed in claim 1, in which the bolt casing comprises one of the following: a tubular body configured to contain the cutting barrier within a cavity extending between opposite ends of the tubular body; or a bar provided with a recess in a side thereof, configured to accommodate the cutting barrier within the recess.

8. The throw lock assembly as claimed in claim 1, in which the cutting barrier comprises a rod or bar.

9. The throw lock assembly as claimed in claim 1, in which the cutting barrier comprises a plurality of barrier members.

10. The throw lock assembly as claimed in claim 1, in which the spacer member comprises at least one of: material that is harder than that of the bolt casing, stainless steel, aluminium, and zinc alloy material.

11. The throw lock assembly as claimed in claim 1, in which the spacer member comprises a bar having with a recess configured to accommodate the cutting barrier.

12. The throw lock assembly as claimed in claim 1, in which the bolt casing defines an elongate cavity, in which the cutting barrier and the spacer member is enclosed, extending between opposite ends of the elongate cavity.

13. The throw lock assembly as claimed in claim 1, in which the bolt casing comprises a tubular body having opposite ends, to which respective end plates are attached, and the cutting barrier and the spacer member are in the form of rods that are housed within a cavity of the bolt casing and extend between ends of the cavity.

14. A throw bolt assembly of a throw lock assembly, the throw bolt assembly comprising: a cutting barrier and a bolt casing to house the cutting barrier, the cutting barrier being harder than the bolt casing, and the bolt casing being more corrosion-resistant than the cutting barrier; a throw portion of a throw bolt including at least a portion of the cutting barrier, and an entirety of said portion of the cutting barrier in the throw portion will be shielded; comprising: a spacer member housed within the bolt casing, arranged between the cutting barrier and a side wall of the bolt casing; in which the spacer member comprises material having lower hardness than the cutting barrier; and the throw bolt assembly comprising: a drive mechanism to move the throw bolt in use between non-locking and locking positions, responsive to an engagement member of the drive mechanism being inserted into a recess provided in the throw bolt and applying a force to the throw bolt; in which the spacer member is configured such that the recess is formed through the side wall of the bolt casing and into the spacer member, without passing through the spacer member; and in which the bolt casing comprises a tubular body having opposite ends, to which respective end plates are joined, and the cutting barrier and spacer member are in the form of rods that are housed within a cavity of the bolt casing and extend between ends of the cavity.

15. The throw bolt assembly as claimed in claim 14, in which the bolt casing defines an elongate cavity, in which the cutting barrier and the spacer member are enclosed, both extending between opposite ends of the cavity.

16. The throw bolt assembly as claimed in claim 14, in which the spacer member comprises a rod having a thickness of at least 5 mm and at most 14 mm, and a width of at least 5 mm and most 20 mm.

17. The throw bolt assembly as claimed in claim 14, provided unassembled.

18. The throw bolt assembly as claimed in claim 14, comprising a bolt holder to moveably accommodate the throw bolt, the bolt holder comprising: a channel extending between proximal and distal ends, the channel configured such that the throw bolt is configured to slide coaxially within the channel, between a retracted position and a projecting position, in which when the throw bolt is in the projecting position, the throw portion of the throw bolt includes a distal end of the throw bolt and projects from the distal end of the channel; and when the throw bolt is in the retracted position, the distal end of the throw bolt will be relatively more proximate to the distal end of the channel than when the throw bolt is in the projecting position; and in which the bolt holder and the throw bolt are configured such that the throw portion of the throw bolt includes said portion of the cutting barrier, and the entirety of said portion of the cutting barrier in the throw portion is shielded.

19. A method of assembling a throw bolt assembly as claimed in claim 14, the method including: assembling the throw bolt, and using a tool to remove material from the side wall of the bolt casing and from the spacer member adjacent the side wall, to form at least one recess into the spacer member, the recess not passing through the spacer member, the recess configured and arranged to accommodate an engagement member of a drive mechanism of the throw lock assembly, to engage and move the throw bolt in use between the non-locking and locking positions.

20. The method as claimed in claim 19, including boring a plurality of recesses into the spacer member, the recesses arranged in a row.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Non-limiting example arrangements of throw lock and throw bolt assemblies will be described in more detail with reference to the accompanying drawings, of which:

(2) FIG. 1A shows a schematic perspective view of an example lock assembly, and FIG. 1B shows a partially exploded perspective view of the example lock assembly;

(3) FIG. 2A shows a schematic front view of an example lock assembly attached to a schematic gateway, and FIG. 2B shows a transverse cross-section through a part of the example lock assembly and a part of the gateway;

(4) FIG. 3A shows an exploded view of an example lock assembly; FIG. 3B shows a bracket and an example sheath of an example bolt keeper; and FIG. 3C shows a top view of the example sheath, as well as cross-section views of the sheath on the planes A-A and B-B;

(5) FIG. 4A shows a schematic exploded perspective view of an example throw bolt; FIG. 4B shows (centre) a bottom view of an example bolt, (upper) a longitudinal cross-section view through the bolt on the plane D-D, and (bottom) a transverse cross-section view through the bolt on the plane C-C;

(6) FIG. 5 shows a perspective view of an example lock cylinder, and a front view of a gear wheel mechanism for engaging the throw bolt;

(7) FIG. 6 shows a schematic exploded perspective view of an example throw bolt;

(8) FIG. 7 shows a schematic exploded perspective view of part of an example throw bolt;

(9) FIG. 8 shows a schematic exploded perspective view of an example throw bolt;

(10) FIG. 9A shows a schematic exploded perspective view of an example throw bolt; and FIG. 9B shows a longitudinal cross-section view through the example bolt; and

(11) FIG. 10A to FIG. 10F show views of certain parts of an example throw lock assembly, including dimensions in units of millimetres and degrees; in particular, FIG. 10A shows a front view of the locking assembly, arranged as installed on a gateway and in the locking position; FIG. 10B shows a longitudinal cross-section view (upper) and a bottom view of an example throw bolt; FIG. 10C shows transverse (left) and longitudinal (right) cross-section views through an example bolt casing tube; FIG. 10D shows transverse (left) and longitudinal (right) cross-section views through an example cutting barrier rod; FIG. 10E shows transverse (left) and longitudinal (right) cross-section views through an example spacer rod; and FIG. 10F shows a longitudinal (upper) and top view (lower) of an example sheath for a bolt keeper.

DETAILED DESCRIPTION

(12) With reference to FIG. 1A to FIG. 10F, example throw lock assemblies 100 for locking a gateway 200, 200A, 200B may comprise a throw bolt 110, a bolt holder 130 and a bolt keeper 120. The bolt keeper 120 may comprise a metal bracket 122 for receiving an end portion of the throw bolt 110. The bolt holder 130 houses the throw bolt 110, such that the throw bolt 110 can slide within the bolt holder 130 between non-locking and locking positions. The bolt housing 130 and bracket 120, 122 may comprise plates provided with screw-holes 152 (FIG. 2A), through which screws 150 (FIG. 3A) can be driven to attach the bolt housing 130 and bracket 120, 122 to respective gateway members 200A, 200B (shown in FIG. 2A). For example, the bolt holder 130 may be attached to a door panel or a gate, and the bolt keeper 120 may be attached to a corresponding door frame, gate post or wall; or the bolt keeper 120 may be attached to a door panel or a gate, and the bolt holder 130 may be attached to a corresponding door frame, gate post or wall. FIG. 2B shows a transverse cross-section view of the example throw lock assembly 100 mounted onto the gateway member 200A, the view being from the proximal end 111. The throw lock assembly may have a long throw, in which the throw bolt may travel a throw distance of about 80 mm between the non-locking position and locking positions.

(13) When the throw bolt 110 is coupled to the bolt holder 130 as in use, a throw portion T of the throw bolt 110 will project from a fore end 131 of the bolt holder 130 when the throw bolt 110 is positioned relative to the bolt holder 130 as in the locking position, as illustrated in at least FIG. 2A. When the throw lock 100 is arranged as in use, an intermediate portion 109 of the throw portion T will extend from the fore end 131 of the bolt holder 130 to the nearest end of the bolt keeper 120, the intermediate portion 109 having a length G. In the example illustrated, the fore end 131 of the bolt holder 130 and the nearest end of the bolt keeper 120 lie on respective planes, each perpendicular to the longitudinal axis L of the throw bolt (shown in FIG. 2A). In the illustrated example, the throw bolt 110 has substantially the shape of a square rectangular prism extending from a proximal end 111 to a distal end, and the throw portion T also substantially has the shape of a square rectangular prism, extending from the fore end 131 of the bolt holder 130 to the distal end 119.

(14) The throw bolt 110 may have the external form of an elongate square rectangular bar having proximal and distal ends 110A, 110B, the end portion of the throw bolt 110 being adjacent the distal end 119. Substantially the whole (external) surface of the throw bolt 110 may comprise stainless steel for good corrosion resistance, which may be particularly—but not exclusively—relevant where a throw lock assembly 100 is used on an outdoor gateway. The throw lock assembly 100 may also comprise a single or double locking cylinder 140 and cylinder cover 142 for a key mechanism to move the throw bolt 110 in use, between the non-locking and locking positions. The throw lock assembly may comprise other components, such as an escutcheon and lock base.

(15) When the throw bolt assembly 100 is installed on a gateway 200A, 200B, the throw bolt 110 can slide within the bolt holder 130, in response to rotation of a gear wheel 144 (shown in FIG. 5) mounted in the locking cylinder 140 and driven by the action a key mechanism. The gear wheel 144 may have a plurality of teeth 146 arranged radially around its circumference, and the throw bolt 110 may have corresponding recesses 115 (shown in FIG. 4B) provided in an under-side of the throw bolt 110, arranged in a row and shaped to receive the teeth 146 with sufficient purchase for the teeth 146 to engage and drive the throw bolt 110 between the non-locking and locking positions in use. When the throw bolt 110 is in the non-locking position, it will be maximally retracted from the bolt keeper 120 to allow the gateway to open, and when it is in the locking position (as shown in FIGS. 1A, 1B and 2A), the throw bolt 110 will maximally project from the bolt holder 130, its end portion being inserted into the bolt keeper 120.

(16) When the throw lock assembly 100 is installed on a gateway for use, and throw bolt 110 is in the locking position, an intermediate length 109 of the throw bolt 110 will extend over a gap length G from an end (fore-end) of the bolt holder 130 to the nearest end of bolt keeper 120, across a spacing between the respective gateway members 200A, 200B. In this position, the throw bolt 110 will interlock the bolt holder 130 and the bolt keeper 120, thus locking the gateway. The intermediate length 109 will be a portion of the throw bolt 110 that may be accessible to an intruder attempting to break in through the gateway, and may be a target for a break in attack. For example, an intruder may attempt to break in by sawing (or cutting or boring) through the intermediate portion 109 of the throw bolt 110, by means of a tool having a steel blade, tip or bit, which may operate by causing abrasive wear of the throw bolt 110.

(17) In the particular example shown in FIGS. 1A and 1B, the bolt keeper 120 comprises just the metal bracket configured for receiving an end portion of the throw bolt 110, and in the example shown in FIGS. 2A and 2B, the bolt keeper 120 may comprise a metal bracket 122 and a plastic sheath 124, in which the sheath 124 is fitted within the bracket 122 and is configured for receiving the end portion of the throw bolt 110. With reference to FIG. 3B, an example sheath 124 may be provided as a separate member, which can be inserted into the bracket 122 and mounted against a gateway member by means of the bracket 122. In the example shown, the sheath 124 may comprise a tubular body 123 having a cavity extending between proximal and distal ends, the proximal end 121 being configured for receiving the end portion of the throw bolt 110 in use. The example sheath may comprise respective flanges 125 provided at each open end, configured such that the bracket 122 will fit between the flanges 125 and the flanges will resist or prevent the sheath 124 from being extracted from the bracket 122.

(18) In the particular example shown, the tubular body 123 of the sheath 124 comprises four side walls, arranged to define a substantially square rectangular cavity 127 corresponding to the shape and dimensions of the throw bolt 110. In some examples, the sheath 124 may be formed by a method including extrusion and/or moulding of plastic material. One of the side walls 126 will be positioned against the gateway member 200B (or 200A) when installed for use, and provide a buffer that will space the end portion of the throw bolt 110 apart from the gateway member 200B when the throw bolt is in the locking position. The tubular member 123 may comprise a tongue 128 depending from an opposite side wall at an angle of about 10 to 15 degrees. The tongue 128 extends away from the proximal end 121, such that when the throw bolt 110 is inserted into the sheath 124, it will urge the tongue 128 to deflect towards the side wall from which it depends, the tongue 128 providing some resistance to the insertion of the throw bolt 110. In this example, the tongue is formed as an integral part of the tubular member 123 and consists of the same resilient plastic material, and is disposed so that it will allow the throw bolt 110 to be inserted into the cavity, and once the throw bolt 110 has been fully inserted (in the locking position) the tongue 128 will bear on the throw bolt 110 and urge it against the buffer side wall 126. The clamping force applied to the throw bolt 110 by the tongue 128 may be sufficient to resist movement of the throw bolt 110 within the bolt keeper 120, which might tend to arise from wind or other incidental forces acting on the gateway members 200A, 200B. Consequently, the bolt keeper 120 may have the aspect of reducing or substantially preventing the throw bolt 110 from rattling within it. In this example, the buffer side wall 126 of the sheath 120 is also formed as an integral part of the tubular body 123, and also consists of the same resilient plastic material as the rest of the sheath 120. It may provide the additional aspect of preventing, or at least reducing the risk of the throw bolt 110 from scratching the surface of the gateway member 200B (200A) as it is moved between the non-locking and locking positions in use. This may be especially relevant when the gateway member 200B (200A) comprises high quality, relatively costly wood or other material that is softer that stainless steel.

(19) With reference to FIGS. 4A and 4B, example throw bolts 110 may comprise an assembly of a bolt casing 116, 110A, 110B, a cutting barrier 112 and a spacer member 114. The bolt casing comprises a casing tube 116 and a pair of end plates 110A, 110B welded to the proximal and distal ends, respectively, of the casing tube 116. The casing tube 116 and end plates 110A 110B consist of 304 stainless steel (in other examples, the stainless steel may be another grade, such as 316 stainless steel). The casing tube 116 is in the form of a right rectangular tube having a width of about 18 mm, a length of about 170 mm and side walls of having a thickness of about 1 mm. Each end plate 110A, 110B may be about 2 mm thick at their edges. The cutting barrier 112 and the spacer member 114 may consist of rods having the general shape of right rectangular prisms, each having a length of about 168 mm, and a transverse cross section height of about 8 mm and breadth 16 mm. The cutting barrier rod 112 may consist (apart from a minor amount of impurities) of hardened steel grade Q235, and may have a surface finish formed by zinc plating, and the spacer rod by consist (apart from a minor amount of impurities) of 201 stainless steel, or aluminium. When the throw bolt 110 is assembled, the cutting barrier rod 112 and spacer rod 114 will be enclosed within the casing body 110, between the end plates 110A, 110B, the spacer rod 114 and cutting barrier rod positioned against an opposite internal surfaces of respective side walls of the casing tube 116. A hole 117 may be provided through the bolt casing 116 and into, or through, the cutting barrier rod 112, for accommodating a resilient biasing means such as a spring, which may bias the throw bolt 110 against an internal side surface of the bolt housing 130 in use. A ball bearing (a ball bearing and corresponding biasing means in the form of a coiled spring are indicated as 160 in FIG. 3A) may be positioned between an end of the spring (the end that will protrude from the hole 117) and the internal surface of the bolt holder 130, such that when the throw bolt 110 is moved within the bolt holder 130 between locking and non-locking positions, the spring can urge the throw bolt 110 away from the internal surface, for example to reduce or eliminate potential rattling of the throw bolt 110 within the bolt holder in use, and the ball bearing can roll along the internal surface of the bolt holder 130 to reduce friction between the spring and the internal surface, and thus provide smooth movement of the throw bolt 110 between the locking and non-locking positions. When the throw bolt assembly 100 is assembled as in use, the hole 117 will house the biasing means and will face the internal surface of the bolt holder 130. Consequently, the hole 117 will not be in the throw portion T of the throw bolt 110, and the cutting barrier 112 will in effect be shielded from the external environment by being covered within a housing provided by the bolt holder 130 (in addition to the spring and ball bearing 160).

(20) In some examples, the casing tube 116, end plates 110A, 110B, cutting barrier rod 112 and spacer rod 114 may be provided unassembled, potentially in kit form, and the throw bolt may be provided by assembling these parts. In this example, a row of twelve blind holes 115 may be formed into the side of the throw bolt 110 against which the spacer rod 114 is positioned (in other example arrangements, different numbers of blind holes may be formed, depending on the throw of the lock assembly). Each of the blind holes 115 has a generally cylindrical shape and a flared mouth (the mouth formed by a conical internal surface area, having a cone angle of about 30 degrees), configured to receive the teeth 146 of the gear wheel 144 coupled to the key mechanism housed in the locking cylinder 140 (as shown in FIG. 5). Each blind hole has a depth of about 6 mm, a diameter of about 5.6 mm at the depth, and a diameter of about 7 mm at the mouth, and the central axes of successive holes may be about 8 mm apart from each other. Each hole 115 extends through a side wall of the casing tube 116 and to a depth of about 5 mm into the spacer rod 114 (in this example, the holes do not extend through the spacer rod).

(21) In some examples, the holes 115 for the gear teeth 146 may be formed after the throw bolt 110 has been assembled. Owing to the presence and arrangement of the spacer rod 114, the holes may be bored into the throw bolt 110 by means of a hand-held tool comprising a steel blade, bit or tip, since in this example it will not be necessary to bore into the hardened steel cutting barrier rod 112. This may have the aspect of allowing the holes to be bored when the lock assembly is being installed on a gateway (in examples arrangements that do not comprise a spacer member, it may be necessary to form the holes 115 into the cutting barrier 112, which may require specialist tools having a cemented carbide blade, tip or bit, due to the high hardness of the cutting barrier).

(22) When the lock assembly 100 is installed on a gateway 200A, 200B for use, and the throw bolt 110 is in the locking position, the intermediate length 109 extending from for fore-end of the bolt housing 130 and the nearest end of the bolt keeper 120 may be about 26 mm in the illustrated examples (in various example arrangements, and for various throw lengths, the intermediate length may be about 10 mm to 30 mm).

(23) With particular reference to FIG. 6, an example throw bolt 110 may comprise two cutting barrier rods 112-1, 112-2; both may have the same shape and dimensions, and consist of the same material, such as hardened steel. In this example, the throw bolt 110 comprises a spacer block 114, provided with two grooved recesses 114R-1, 114R-2 having semi-circular transverse cross-sectional shape, for accommodating the respective cutting barriers 112-1, 112-2. The cutting barriers 112-1, 112-2 may be solid cylindrical rods, and each of the grooves 114R-1, 114R-2 may be semi-circular troughs. A central portion of the spacer block 114 may be disposed between the respective opposite ends of the cutting barriers 112-1, 112-2, spacing them apart longitudinally. In some variants of the example, the spacer block 114 may consist of (or comprise) steel or zinc alloy material.

(24) In other versions of the example arrangement described with reference to FIG. 6, there may be more than two cutting barriers; for example, there may be three, four, five, six, or up to about ten cutting barrier rods. The cutting barrier rods may all have substantially the same size and/or shape, or they may have different sizes and/or shapes; they may comprise or consist of the same material, or different materials (or different grades of the same kind of material).

(25) With particular reference to FIG. 7, an example throw bolt 110 may comprise a casing body 116 and a cutting barrier 116, in which the casing body 116 has a substantially square rectangular external shape and defines a cavity in the form of a square rectangular recess 116R, having an open side. The cutting barrier may be in the form of a hardened rod 112 consisting (apart from unavoidable impurities) of hardened steel, and may be substantially square rectangular in shape. In the illustrated example, the recess 116R extends between closed opposite ends of the casing body 116, and one of the sides of the casing body 116 can be open to receive the hardened rod 112. The shape and size of the recess 116R in the casing body 116 may be substantially the same as that of the hardened rod 112 (with sufficient tolerance for the hardened rod 112 to fit in the recess 116R. When the throw bolt 110 is assembled for use, the hardened rod 112 will be placed into the recess 116R, and a cover plate (not shown) can be placed over the opening of the recess 116R and welded to the casing body 116, to wholly enclose the hardened rod 112 within the bolt casing 116 (which will include the cover plate), apart from the relatively small hole 117 for accommodating a spring (not shown) that may bias the throw bolt against an internal side surface of the bolt holder in use. Once the throw bolt 110 has been assembled, a plurality of holes 115 may be bored through the cover plate and into the hardened rod 112, having size and shape for accommodating teeth of a drive mechanism coupled to a key mechanism, for moving the throw bolt 110 in use, between non-locking and locking positions.

(26) With reference to FIG. 8, an example throw bolt 110 for a lock assembly 100 may comprise a bolt casing 116, 116P, and a cutting barrier rod 112 that will be enclosed by the bolt casing 116, 116P and extend over at least a portion of the throw bolt 110 corresponding to the intermediate length 109 when installed for use. In the particular example illustrated, the bolt casing 116, 116P may comprise a casing block 116 and a cover plate 116P. The casing block 116 may have the general shape of a square or rectangular prism, and include a groove or recess 116R formed into a side thereof, for housing the cutting barrier rod 112. The recess 116R and the cutting barrier 112 may have the shape of an elongate plate, or strip, the opposite ends of which may be semi-circular. The cover plate 116P may have substantially the same shape as the cutting barrier 112 when viewed from a side, although its thickness may be less. The depth of the recess 116R exceeds the thickness of the cutting barrier 112 so that when the cutting barrier 112 is located within the recess 116R as in use, the cover plate 116P can be placed over the cutting barrier 112, with its outer surface being substantially flush with the external surface of the casing block 116. Thus, the cover plate 116P will entirely cover the cutting barrier 112 when the throw bolt 110 is assembled. Through-holes may be provided in the cutting barrier 112 and in the cover plate 116P for accommodating fastening pins (such as screws or bolts) 118 for fastening the cover plate 116P against the cutting barrier 112, thus securing it in place within the casing block 116. The tolerance of the fit between the cover plate 116P and the casing block 116 may be sufficient to prevent or reduce environmental water or other chemical agents from degrading the cutting barrier 112. The casing block 116 and cover plate 116P may consist of stainless steel.

(27) With reference to FIGS. 9A and 9B, the throw bolt 110 may comprise a cutting barrier 112 in the form of a solid cylindrical rod, the length of which may be substantially the same as the length of the cavity 116C of the casing tube 116. The end plates 110A, 110B and the respective ends of the cutting barrier may be cooperatively configured so that the cutting barrier can be held in place at its ends, by the respective end plates 111, 119. In examples like this, the cutting barrier 112 may be at least partly surrounded by a gap between its cylindrical surface and the surface of the cavity 116C. A plurality of blind holes 115 for the gear teeth 146 of the key mechanism may be formed into through the wall of the casing tube 116, arranged in a line.

(28) Example disclosed bolts may good resistance to corrosion, since the sheath may define an external surface of the bolt having high corrosion resistance. Corrosion resistance can be measured by mean of a ‘salt spray’ (or ‘salt fog’) test, which is a standardise corrosion test method that can be used to measure the corrosion resistance of materials and surfaces, particularly but not exclusively metallic materials. The ‘salt spray’ test method involves exposing a surface to be tested to a corrosive environment for a certain period of time, after which the appearance of corrosion products (rust) is detected and quantified. The period of testing may depend on the corrosion resistance of material being teste. In general, the more corrosion resistant the surface is, the longer the period required before sufficient evidence of corrosion, such as rust, will appear. A standard for the corrosion resistance of building hardware is the European standard EN 1670. An internationally recognised standard salt spray test is ISO 9227 (a standard of the International Organization for Standardization). Other standards include ASTM B117 (a standard of the American Section of the International Association for Testing Materials™), JIS Z 2371 (a standard of the Japanese Industrial Standards) and ASTM G85. The Neutral Salt Spray (NSS) test may be used for testing steel-based materials, and involves using a test solution having a neutral pH of 6.5 to 7.2. The results can be expressed as a number of hours before the appearance of corrosion products (for example, a result may be expressed as 700 hours in NSS according to the ISO 9227 standard, and/or the EN 1670 standard).

(29) The bolt casing may substantially enclose the whole of the cutting barrier; the bolt casing may prevent direct ‘line-of-sight’ access to the cutting barrier from the external environment, particularly direct access by environmental water such as rain. In some example arrangements, the throw bolt assembly may be configured such that when assembled as in use, the arrangement of the bolt casing and bolt holder, and the spacer member in some example assemblies, may substantially avoid line-of-sight direct access by rain or other potentially corrosive agents to the cutting barrier. For example, in some arrangements, one or more holes may be provided through the bolt casing (for example, for accommodating a biasing means such as a spring to bias the throw bolt within the bolt holder; or for accommodating gear teeth of a drive mechanism for moving the throw bolt between the non-locking and locking positions in use), and when the lock is assembled for use, the hole or holes may be covered or blocked by a member of the lock assembly, such as a part of the bolt holder, when the throw bolt is in any position from the non-locking to the locking positions (i.e. in any condition of normal use); and/or the hole or holes may terminate in a spacer member. In other words, if a hole or holes are provided through the bolt casing, another component of the throw lock assembly (for example a spacer member contained within the bolt casing, or a part of the bolt holder that external to the bolt casing) may provide a protective barrier between the cutting barrier and the external environment, to substantially prevent, or to reduce the risk or rate of corrosive or other chemical wear of the cutting barrier, which may potentially be caused by agents such as rain water from the external environment.

(30) As used herein, ‘gateway’ and ‘doorway’ may be used interchangeably, and may refer to indoor or outdoor access systems for buildings, gardens, driveways or real estate generally, in residential, industrial, or agricultural constructions, for example. A gateway may comprise a moveable barrier that can be arranged to prevent or enable access through another barrier, which may be fixed, such as a wall, fence, or hedge. The moveable barrier may comprise or consist of door, gate, panel, leaf, stile or rail, for example, side of which may be coupled to the fixed barrier, a frame, door casing, or gate post, for example, by means of a sliding, rotating, or hinge mechanism. A lock assembly may be installed on the gateway to prevent or resist the moveable barrier from being moved relative to the fixed barrier, thus locking the door or gate.