GB2408304A

GB2408304A - Crime prevention seat

Info

Publication number: GB2408304A
Application number: GB0504129A
Authority: GB
Inventors: Mamoru Ueno
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-09-19
Filing date: 2002-03-28
Publication date: 2005-05-25
Anticipated expiration: 2022-03-28
Also published as: GB2403522A; GB0504129D0; GB2408304B; GB0422115D0; GB2403522B

Abstract

A crime prevention seat (40) for a screw fastener is toroidal in shape having a central aperture and a rise portion (40a). The rise portion (40a) is suitable for surrounding a head of the screw fastener to prevent the screw fastener from being tampered with.

Description

CRIME PREVENTION SEAT

FOR USE WITH A CRIME PREVENTION SCREW

This is a divisional patent application of Application No. 0207391.4 filed on 28 March 2002 (publication no. GB 2379961A).

BACKGROUND OF THE INVENTION

Field of the invention

The present invention relates to a crime prevention screw that after the screw is tightened in desired places, a recessed portion, such as square socket, hexagon socket, cross socket and slot, formed on a screw head is covered and hence drawing-out of the screw with the intention of prank and crime can be prevented, an embedding material of a screw head for embedding in a recessed portion of the crime prevention screw, a screwuse crime prevention seat for preventing the crime prevention screw from being drawn out using tools such as pincers and pliers, and a crime prevention screw set composed of their combination.

Description of the related art

A screw of the conventional art is constituted so that a screw head is formed on a base end of a screw main body where a spiral groove is formed on its outer peripheral surface. Such a screw has heads of various shapes.

Example of a machine screw are a flat fillister head screw, a round head screw, an oval fillister head screw, a pan head screw, a binding head screw, a truss head screw, a countersunk fillister head screw and an oval head screw.

These screw heads are formed with recessed portions composed of sockets or grooves such as a square socket, a hexagon socket, a cross socket and a slot for engaging an end por ion of a tool such as a square spanner and a driver and rotating the screws.

Another example is a bolt having a hexagonal head (screw head) which is one kind of a screw, and this bolt head (screw head) is formed with such a recessed portion.

In addition, conventionally a flat seat having a doughnut shape viewed from too which is fitted into a screw main body and is received by the screw head is used for the above screws.

These screws are used in various fields. For

example, as shown in Figs. 1 and 2, a number plate 2 is attached to a car body 1 of an automobile A by using screws 3, 3. In this case, conventionally screws 31, 31 having a hexagonal head that the surface of the hexagonal head is formed with a cross socket, or circle fillister head screws are generally used.

Further, a car stereo and a car navigation device which are provided in a root of the automobile A are similarly fixed by countersunk head screws.

In addition, as shown in Figs. 3 and 4(a), for example, a metal-made crime prevention grid P is generally attached to an outside of a window W of a house for crime-prevention countermeasure. Lattice main bodies 4, and upper and lower later_' r.aterials 5 and 6 of tr,e metal grid B are assembled and fixed also by using screws 3. In this ca e, as shown ir rig. 4(b), coup ersa?k head screws 32 that a cress socks- is orec cr their screw heads, circle -illis -r he_c screws or pan head screT.vs, rot short, are used. Moreover, as shown in Figs. 4(a) and 4(b), also in th- case where the grid ? is attached to the outsit_ c- the T,4;'2 rod.; i, Or._ grip P is _ixed to a sash 7 that an end portion of a stay 6 of the grid P is formed integrally Edith a window rail by using slightly larger screws 3 such as countersunk head screeds or pan head screws.

When the number plate 2 is attached to the car body 1 and the grid P is attached to the outside of the window W by using the above-mentioned various screws 3 of the conventional art, the following problems arise.

More concretely, even if the number plate 2 is attached to the car body 1 by using the screws 3 (for example, the screws 31, 31) of the conventional art, the screws 3 (31) can be drawn out by using a tool such as a plus driver or a small spanner. For this reason, when or after a car is stolen, the number plate 2 is easily removed or easily replaced by another one.

When the number plate 2 is removed or replaced by another stolen number plate, it is difficult to find the stolen car. For this reason, the case that stolen high- grade cars are exported abruptly increases in many places. Moreover, cases of stealing, robbery and kidnap using stolen cars with feigned number plates occurred frequently in times past. Further, the case that screws which fix a car stereo and a car navigation device to the automobile A are loosened and these devices are stolen are inreas fig. As mentioned above, when the lattice main bodies 4, arc' t:r.e,op-r and lc;; er stays 5, 6 a-e fixed by Vising the screws 3 (_2) or the con-e.tional arc a. the grid P is attach_c to he sash 7 b,- sin_ the screws 3 of the con/etio.nal art, thes- scre-;s 3 (32j, 3 are drawn out on the outside of a house so that the lattice main bodies 4 and th- enire grid P call be re=..o-vred easily. In particular, inhabitants consider that the crime prevent on is sufficient because the grid is attached to the outside of the window W. so that they frequently leave the window W open and unlocked. For this reason, the case that a thief removes the grid R easily and opens a screen 9 and the window glasses 10, 11 and intrudes through the window W into the house and infringes stealing and felonious crime occurs frequently. At.

In the light of the fact that the screw can be remove easily as one reason which easily causes the above cases, the inventors of the invention have proceeded to develop a new screw which cannot be easily removed after it is once tightened. As a result of their enthusiasm examination, finally they have devised a crime prevention screw which cannot be loosened or removed even by using a tool such as a driver or a square bar spanner after the screw is once tightened, a screw head embedding material which can be used for not only this crime prevention screw but also screws conventionally in the market, and a screw-use crime prevention seat which prevents a screw head from being pinched and being rotated through a tool such as pincers or a spanner.

SUMMARY OF THE INVENTION

In is an ObJ eat of the present invention which has been finished through such a prehistory to provide a chine pr=V-n or- sore;: that a ter the sore, is ticater.e in predetermined places, a. e,edaing material is eb_d_ in a recessed. portico cc...posed Of a square socket, a..e':agon socke, a cross socket or a slot formed on a screw head so that the screw can be prevented from being -'awn out w th t;.e inte..tion o many- pranks and malignant crimes. Example of such crimes are car stealing through removal of a Comber plate of an automobile, resale and export of stolen automobiles, stealing and robbery or kidnapping using a stolen car, stealing of a car stereo and a car navigation device in an automobile, intrusion of a thief and a public enemy through a window into a house by means of drawing out of screws for fixing a grid to the window or screws for attaching a grid to a sash of the window.

Further, it is an object of the present invention to provide an embedding material of a screw head which embeds in screw heads of various screws including such a crime prevention screw and is capable of fixing the screws so as to prevent the screws from being drawn out.

Furthermore, it is an another object of the invention to provide a screwuse crime prevention seat which can prevent a prank that the screw head is pinched by pincers or pliers to be loosened and drawn out (in the case where such prank cannot be prevented by even using the crime prevention screw and the embedding material) and the above-mentioned crimes derived from this prank.

Further, it is still another object of the invention to provide a crime prevention screw set composed of the crime prevention screw and the embedding material or a crime prevention screw set composed of the crime prevention screw and the embedding material andthe screw-use crime prevention seat.

r. crime prevention screw of the preset. ir.ven_ion from G -' rst aspe t w- ch is on- ,_...ea-.s tc solve the above problems, is chara-.erize in.--t _ recessed portion which is composed of a square socket, a hexagon socket, a CEQSS socket Cal -. slot for e-. _gir.g and rotating an end portion of a tool such as a square bar spanner or a driver is omed on a screw head, and a recessed engagement portion is formed or. a partial place of an inner wall of the recessed portion such that one of an expanded portion formed by buckling a part of an embedding material for embedding in the recessed portion and a protrusion to which a force is applied to the side of the embedding material for embedding in the recessed portion comes into the engagement portion, whereby the embedding material is prevented from coming off.

The basic technical idea of the crime prevention screw of the present invention is characterized in that after the screw is tightened, an embedding material is embedded in a socket or a groove such as a square socket, a hexagon socket, a cross socket or a slot so as not to loosen and remove the screw using a tool such as a square bar spanner or a driver. However, only when the embedding material simply embeds in the socket or the groove, the embedding material easily comes off or is drawn out forcibly by catching it through an end of the tool such as a driver. For this reason, the inventors have finished the crime prevention screw in combination with a plurality of techniques for preventing the embedding material from coming off.

Tts one example is the crime prevention screw of the first aspect. The crime prevention screw is a n-_2cgism that a screw:,:-i r2- C-.. take a c. ime-prevention - -so-- s simplif en.. . .h- S:^^ or the groove s:-2:-1 as a stare so_'e., a hexago- socks, s cross so_ke.

Or a slot formed on a screw head cannot be expressed by a --.-ric term, the recense_ _c- -an is cased in the present _: .; _ A! ' - a -I _ _ Hi'_ ^ -'i 'i t a:<-i- e s s i _ - . In the present invention, before the explanation about how to embed a.d fix the e...oedding material in/io the recessed portion formed on the screw head of the crime prevention screw of the first aspect, the embedding material to be used in the first aspect will be simply explained.

In the present invention, the most suitable examples of the embedding material to be used for the crime prevention screw of the first aspect are the following two kinds of embedding materials. One is an embedding material which has a size and a shape such that it can fitted into the recessed portion of the screw head of the crime prevention screw in a state that its one portion remains outside and is formed by a soft material such that at least its end portion is buckled easily.

This embedding material is embedded into the recessed portion by tapping the portion extended from the recessed portion using a hammer or the like until this portion is flush with the screw head and buckling the end portion.

The other one is an embedding material which has a size such that it can just fitted into the recessed portion and has a vicinity portion including the end of its side surface to which a force directing outward is applied and is formed with a protrusion facing sideways ^-t -ts egg ooriD-i.

In the present invention, the crime prevention sir_; -, me rs' -s?^- s cor.situte so that _ so:: .^ :: -c =. -- a At - ? of he inn- ,ial o- t.-. r-:_ssed portion a.-; c: po__i cr.

or a protrusion of the embedding material which is Guc:clec to b- e:;-.. ^^ si-e;i-,s is p;,sh:d in 0 the _. _, . .. ..., . .. .. . , .. a. . c: . ., _ \ _... _. . _ v _ _ _. . , _ = _ _. _ _ _ c.. . _ a. _ _. i _. . . _. _ _ _. _ _.

prevented from coming out of the recessed portion.

T.s 'or the most suitable place of the inner wall of the recessed portion where the engagement portion is provided, the inward end portion of the inner wall is the most suitable, and it is the most suitable that the engagement portion is formed slightly wide to be slightly higher than the inward end portion. This is because the buckled and expanded portion of the above-mentioned former embedding material easily come into and is engaged with the recessed portion and the applied force of the abovementioned latter embedding material acts the most efficiently.

In addition, in the case where, for example, the recessed portion is a hexagon socket, as to the engagement portion is formed wide along its entire periphery or a part of the engagement portion is formed wide is not necessarily limited. However, the former state is the most suitable because the engagement due to the buckling and the protrusion should be desirably carried out securely.

The shape of the engagement portion is not particularly limited as long as the buckled portion and the protrusion come into the engagement portion easily and they do not comes out of it. It is necessary to pr^i-. rd a shape such ha. the recessed portion is not cracked and is deformed or broken when the screw is tic- Ones' by Opel-. -ad score bar sca.ne or a derive' -- In- ,-^ e---; - 's i _ _ _ _. _. _!.. i _ _ _.

Furh_r.._r_, c--_- clitic. o' -.rhe DO' to:-. c- he recessed portion may be formed to be slightly high so t;.-. the e-.iedc.- n m--:eri-1 is buckle_.o be e_sly _; i _, C1 _ Hi S _. _; There will be detailed below a crime prevention screw according to a second aspect of the present invention.

In the present invention, a crime prevention screw of the second aspect is characterized in that a recessed portion which is composed of a square socket, a hexagon socket, a cross socket or a slot for engaging and rotating an end portion of a tool such as a square bar spanner or a driver is formed on a screw head, and a recessed engagement portion where its inside is wider than an entrance is formed on a bottom portion of the recessed portion such that one of a protrusion formed at an end of an embedding material for embedding in the recessed portion and one end portion of a connecting member for connecting the embedding material to the screw head comes into the engagement portion, whereby the embedding material is prevented from coming off.

In the present invention, the crime prevention screw of the first aspect is constituted so that the engagement portion is formed on the side wall of the recessed portion, but the crime prevention screw of the second aspect is constituted so that the engagement portion is formed on the bottom of the recessed portion.

The above-mentioned contents are directly applied to the othe-- portions.

. . . fin the present invention, in both the Crime Fre-er.tio: s r--.^ othe __-ond asp_s. an-. t:-- crir^.

prey nt-o!: sore;, or t_r.' . En'- _ as:*c, c.. emb_..-i-.- material is embedded in the recessed portion of t..e crime prevention screw and is prevented from coming off. The So 'c;;ing ';o kinds Or exb--; -lg.iat-ria's an- -?, red to the crime preen ion. screw- c One second as__.

One is an embedding material that a protrusion, which has a size with an allowance such that it is pushed into the engagement portion formed on the bottom of the recessed portion and is easily buckled, is formed at an end portion of an embedding material main body having a shape such that it can be just embedded in the recessed portion of the crime prevention screw. The protrusion is formed by a soft metal material such as lead, copper, zinc, aluminum or tin, or alloy mainly containing one kind or plural kinds of them.

The other one is an embedding material which is composed of two members: an embedding material main body; and a connecting member. The embedding material main body has a shape such that it can be just embedded in the recessed portion of the crime prevention screw and is formed with a recessed engagement portion, which is opposed to the engagement portion of the crime prevention screw, on its lower surface. The connecting member has a size with an allowance such that it is pushed into both the engagement portions and is formed by a soft metal material, which is easily buckled, such as lead, copper, zinc, aluminum or tin, or alloy mainly containing one kind or plural kinds of them.

The former embedding material which is in the state tha. its pro-rusicn is pushed into ine engagement portion formed on the- bottom of the crime prevention screw is a?_: be a Her '2 the e..b-:l'.--n Material rater b,dv _.. Is. ; . t:_ _: _ _.c _ result, the protrusion is buckled in t:-!_ engagement portion to be expanded sideways, and the em'oedding Material Min 'code -s fixed s-- rely i: to a-.-._ on- Of it.

As for the latter embedding material, in the state Gina one end portion of the connecting me.,ber is put into the engagement portion of the embedding material main body, the other end of the- connecting member is pushed into the recessed engagement portion of the crime prevention screw, and the embedding material main body is tapped by a hammer until it is flush with the surface of the screw head. As a result, both ends of the protrusion are buckled in both the engagement portions so as to be expanded sideways and engaged with them so that the embedding material main body is fixed securely so as not to come out of it.

As to which embedding material is used, it depends upon the size of the crime prevention screw and the height of the screw head. The former embedding material is suitable for the case of a comparatively small screw, and the latter embedding material is suitable for the cases of a comparatively large crime prevention screw and a crime prevention screw that the screw head is comparatively high.

The inside of the engagement portion is wider than its entrance so that the soft metal material is buckled in the engagement portion of the crime prevention screw of the second aspect. The shape of the engagement portion is r.o par icularly limited as ions as the shape can prevent the above-mentioned coming-off. For example, Ah S iamb A.-. A_ It I'-- s - ra' s,_.<et i-t. r?. -i<, -_ h - r.- do,- - A; -- ;.

_, _._. _, _.: . . A type of the crime pre-;e-.-ion screws of the fire'.

and second aspects is not necessarily limited as long as i- sorer, has at leas- the -. m-ntifa*:' en<are..e-r F rcion. Suitable e..amples On various crime pre-ie:-i lo;.

screws having such an engagement portion are a machine screw, a set screw, a square screw, an embedded screw, a bolt and a wood screw, and one of them can be selected.

The machine screw is a small screw which is threaded into a tapped hole. Examples of the machine screw having various screw head shapes are a flat fillister head screw, a round head screw, an oval fillister head screw, a pan head screw, a binding head screw, a truss head screw, a flat countersunk head screw and an oval head screw. The square screw is a screw having square spiral groove and thread. The bolt is a screw corresponding to a nut, and in the present invention the bolt the above- mentioned recessed portion should be formed on the screw head of the bolt. However, in the case where a bolt having a hexagonal screw head is used, a screw-use crime prevention seat, mentioned later, should be used so as to prevent the bolt from being loosened and being removed by a spanner.

The respective recessed portions of the crime prevention screw of the first aspect having such a shape are formed by cutting by means of a tool such as a special gullet cutting edge or a tap or an automatic machine having the cutting edge of these tools at the manufacturing step. Hcwever, a screw in the market can be finished throw r! sac- a process.

- After the crime prevention screw is tightened in d-s r- F aces as e.<p r-d abcv-, We embed.- r mte---.1 i_ e--ed-:. -I:-- re--.^s_- Cur- - c Ah.s I- h^-- o- the crime prevention screw so as not to come out o it.

us a result, the cr-me prevention screw cannot be :;---.ed or -:o--ed b-, us -. a so - Cam- s-_-ner.^ a drive-, and.-lence v--ios c- Yes and pra..ks car He prevented.

Even if the square bar spanner or the d-e- canno be used, in the case here the screw head o- the crime prevention screw has a shape such that the screw head can be pinched by a tool such as pincers or pliers, namely, a shape with comparatively less roundness like a flat fillister head screw, an oval fillister head screw or a pan head screw or in the case of a high set screw with a hexagon socket, these screws can be pinched and rotated by the tool. For this reason, it is desirable that the crime prevention screws having the screw heads of such shapes are changed so as to have a shape such that the screw heads hardly pinched by the tool such as pincers or pliers.

Therefore, as one of its countermeasures, a fourth aspect of the present invention specifies that the screw head of the crime prevention screw of the firs. or second aspect has a curved surface shape such the the screw head is hardly pinched by a pinching tool such as pincers. Namely, the entire screw head has roundness like a round head screw or has an almost flat shape like a flat countersunk head screw.

There will be explained below the embedding material of the present invention.

lr.e e._dding material has var __s shapes corresponding to the recessed portions of the screw head ^. to:._ crib_ o--ev_n On scr-.-;s, a-. :^.^.s v--r -us _.:gage..e-!- s A.:- Arc.: -ti-.g..- ce -,- a.-, mentioned above. The _nv- e-to.s udg-= .ha he present invention cannot be carried out only smith the above- me-. i-nsd crime preventicr. screws and t^._ expecting a ^i= I; lo- =__- c-^.-. c- -..- 'ems:, He embedding material is also constituted so as to cover the scope of right.

One example of such an embedding material is an embedding material of a screw according to a fifth aspect.

The embedding material of a screw head according to the fifth aspect (hereinafter, the embedding material) for embedding in the recessed portion for pushing a tool thereinto, composed of a square socket, a hexagon socket, a cross socket or a slot, the recessed portion being formed on the screw head of the crime prevention screw according to one of the first through fourth aspects, is characterized in that the embedding material has a shape and a size such that it can be buckled in and can embed in the recessed portion and at least an end portion of the embedding material is made of a soft metal material which can be buckled and mainly contains soft iron, lead, copper, zinc, aluminum or tin, or one kind or plural kinds of them.

In the present invention, the embedding material of a screw head according to the fifth aspect (hereinafter, the embedding material) have various shapes corresponding to the recessed portion of the crime prevention screws and has a size such that it is higher than the recessed port o. by assumed bloke Hi. shape o the assui-..ed buckled portion corresponds to a position in the recessed _ -: v^-e -if.-, e-.-.3e-- cr-^- is co-ed.

- - -; :.-. _ -his i; . nTelr _.

has end portions of two kings of shapes.

One shape corresponds to tr.- crime prevention screw :- -- e-. ---:-n pert Con '2 S arc. C '_ s de tall of the recessed portion. Ihe end portlo. o.-1_ embedding material corresponding to the engagement portion has a 1 A shape such that it has a; Ah along the entire bottom.

surface of the recessed portion and has a height for assumed buckling. On the contrary, the end portion of the embedding material corresponding to the crime prevention screw that the engagement portion is formed on the bottom of the recessed portion has a shape such that it has a width which can be inserted into the engagement portion and has a height for assumed buckling.

In the present invention, the embedding material of the fifth aspect is constituted so that at least the end portion for assumed buckling is made of the above- mentioned soft metal material. Namely, the entire embedding material is made of the soft metal material is also included in the present invention. The buckling means that a compressing force is applied from a lateral direction and one portion is deformed to be expanded sideways. For example, the case where one portion is cracked to be expanded sideways is also included in the buckling. As one method, the bottom of the embedding material may be slightly recessed so that the buckling becomes easy.

The embedding material having such a shape is selected according to a type of the crime prevention screw a-.d after the cir Prevent c- screw; i_ ticltened, the embedding material -s tapped- into the recessed peal. . Oi IGMe Or t'r,- sir_- -a. y a.-axer o-- the li'<:.^ a.- , be em'c\- - be.:: i-. t- - ---.^.e-sed F '!r-.2.^i-. O- w-.-e scrip head completely. Since the engagement cue to the buckling is carried out i- the inward end of the recessed port I- Ike embedding m- er al does rot cone Ott, and e-e.. if Or.= e.mbedd rig --a er at is fries to r_..o--ed forcibly by using an end portion of the driver, it does

JO

not come off.

An embedding material of a screw head of a sixth aspect depending from the embedding material of the fifth aspect is characterized in that the embedding material has a shape and a size such that it can be buckled in and can embed in the recessed portion for pushing a tool thereinto, which is formed on the screw head of the crime prevention screw and is composed of a square 'socket, a hexagonal socket, a cross socket and a slot, and is composed of two members: an embedding material main body which is formed with a recessed engagement portion having a shape such that an inside is wider than an entrance at its end surface; and a connecting member which is buckled in both this engagement portion and the recessed engagement portion formed on the bottom portion of the crime prevention screw that its inside is wider than its entrance so as to fix the embedding material main body in the recessed portion of the crime prevention screw and is made of a soft metal material mainly containing lead, copper, zinc, aluminum or tin, or one kind or plural kinds of them.

The embedding material according to the sixth aspect is composed of the two members: the embedding r..erial.-..a n Cody c-- e.=eddin.g in the recessed port on Of the screw head of the crime prevention screw; and the c-.r.^.-c. -. r^.. - --:' -. ..- e.eidi-. =.=e -I =.a-.

, ! -- - -^- .--' S = -- - - , t- 't-'- '' S - . ? ? .-; a. _ r -, be- corresponds to the crime prevention screw or the second aspec'.

The er.=d-r. --: -Sal m_-1 n body Ma, ---- fo-.m.ed by the ao;e-r.er.on_d Scot r.._al.-.a,eral, but -. is desirable that it is formed by a comparatively hard metal maternal sue-. as stainless, iron or super steel such the the shape is not broken when it is tapped into the recessed portion. When the embedding material main body is formed by the comparatively hard metal material, even if the embedding material is broken or chipped or by the end of the driver, it is not influenced at all. When the embedding material main body is formed by the material which is the same as the material of the crime prevention screw, the embedded portion is hardly recognized and the appearance becomes good.

The above-mentioned embedding material is buckled so as not to come off, but the embedding material of the present invention is not limited to this engagement structure.

One example of such an embedding material is an embedding material according to a seventh aspect of the present invention.

An embedding material of a screw head according to the seventh aspect (hereinafter, the embedding material) for embedding in the recessed portion, for pushing a tool thereinto, composed of a square socket, a hexagon socket, a cross socket or a slot and formed on the screw head of the varic s crime prevention screw is characterized in t.._t tr:e e.. beddir!g r-.a'cerial has a space and a size such ! , . that it can be pressed into the recessed portion and an - : :-; _ . _...i.:, i_. . i _. _ _ _ O _! ._ _. it -:--_.:.--c- -.i^- c:::-. ins: .- eng---.e::- per ice. c:..

first or second aspect with a force is applied to the orotrus 0.

-:i e.beddirg r.-.erial corresponds co tie crime preven.iv-. screen tnGc to- e.-.gagemer, por-ior. is crr._d o.-.

the side wall of the recessed portion in the above Mentioned crib.prevention screws. The embedding Material embeds in the recessed portionand the protrusion formed on the end portion on the side wall of the embedding material is pushed into the engagement portion so that the embedding material are prevented from coming off.

This embedding material is roughly classified into two types.

One of them is an embedding material such that four side edges of a metal spring plate are bent downward so as to have a shape corresponding to the inner wall of the recessed portion and the lower end edges is slightly bent outward, preferably obliquely upper outward and when the embedding material is put into the recessed portion, the protrusion as the slightly bent portion is engaged with the engagement portion of the crime prevention screw with a force is applied to the protrusion. The center surface of the embedding material embeds in the recessed portion, and this embedding material corresponds to the crime prevention screw having a large recessed portion due to a problem of figuration. The surface portion at least should not be protruded from the recessed portion.

The other one is a resin-made embedding material and this em_dtin m'erial also has the anproxima ely same shape and function as those of the above-mentioned --be^. no.;- e al f^rr=c by t..e mesa sprung c'--e.

=-_ the e b.-li- m_ -r-2 s e.-.be'---: in he r-::^sse portion of tincrime pr_-v-ntic:. sc-e-, i:- r_r sur-ce should be thick or a metal plate corresponding to a size o the recessed pGr Son should be f-xed 'c the upper s r -_= so :-- t.:- c. ' 7, I_:c'.--- b y the end portion of a driver. The embedding material of the seventh aspect is fixed only oy pressurizing it into the recessed portion of the crime prevention screw.

There will be explained below an embedding material of a screw head according to an eighth aspect of the present invention.

In the present invention, an embedding material of a screw head according to the eighth aspect (hereinafter, the embedding material) is characterized inthat the embedding material is a material for embedding in the recessed portion, for pushing a tool thereinto, composed of a square socket, a hexagon socket, a cross socket or a slot and has a shape and a size such that it can embed in the recessed portion through tapping or pressurizing-into and a suitable portion of its side wall is formed with rags or burrs for preventing the embedding material from coming off.

This embedding material is different from the above-mentioned embedding materials and can correspond also to screws of the conventional art in the market.

This embedding material has a shape such that it can be just fitted into the recessed portion formed on the screw head such as a square socket, a hexagon socket, a cross socket or a slot and is made of hard metal such as iron, stainless or sure- steel. Its side sir ace is formed with rags or burrs.

'.^e Bans. tilts- -otrus-ons ---sing a. acute n_le;^; - c.t into t:^ -^.^.-r w-:1 c t-- r-c_ss*- pccrion for:.e-i on the s_-evi heac and ar_ t--.-d to a direction where the embedding material does not come off.

I. size and a number a- t e -ads are.^G' particularly i;- -: as 2_-.g a._ a --s.;_ e..i_e_ _-. r:..er at __-n be pushed into the recessed portion and is strongly engaged Edith t'ne recessed portion so as nct to come out of it.

The burrs are substitutes for the rags and are formed sideways on a peripheral edge of the end portion of the embedding material.

Such an embedding material is convenient and economical because it can convert various screws conventionally in the market into crime prevention screws.

The above explanation referred to that when the screw head of the crime prevention screw is formed into a round shape, it is hardly pinched by a tool such as pincers or pliers. It is originally desirable that the shape of the screw head can be selected freely according to attaching places, and a shape such that the screw head can be pinched easily by pincers or pliers is occasionally required.

In order to cope with such a case, the present invention according to a ninth aspect is constituted so that even if such a screw is used, the tightened screw is prevented from being loosened or being drawn out by using a crime prevention seat.

A screw-use crime prevention seat of the ninth aspect (hereinafter, the crime prevention seat) having a doughnut strap_ viewed from top suc'.r t'. at the crime prevention seat is fitted into the screw main body of the Or m- Best n'iQn s-e-: according Lo On- Cat- he first :--C,.i-'-. -it - -s Is =.. Is ^ ill, t:-- so-_; :iec., is cr. aracterizci in that a rise porno'-. r.a.g rcund.iess, which surrounds the side wall of the screw head and is h rc_v nipped my - too; ski-- as wincers or pliers, is cr..;--^ arcing Ore s__z.

This crime prevention seat corresponding to a shape and a size of the screw head to be used is prepared. t is desirable that an outer peripheral portion of the rise portion is formed by a round tilted surface like a screw head of a round head screw and its height is about the same as a height of the screw head. A lower step portion surrounded by the rise portion has the approximately same diameter as an outer peripheral diameter of the screw head, and its center is formed with a hole fort inserting the main body of the screw thereinto.

When this crime prevention seat is used, the seat prevents the screw head from being pinched by the tool such as pincers or pliers. Further, even if the crime prevention seat is tried to be pinched by the tool, it cannot be pinched due to slipping. Moreover, the crime prevention seat is tried to be pinched forcibly, only the seat is rotated idly so that the crime prevention screw is not loosen or drawn out. For this reason, the screw cannot be drawn out mockingly or with the intention of crimes. As a result, the crime prevention seat is not required for the screw such as a round head screw having a shape such that its screw head is hardly pinched by the tools.

This crime prevention seat is used together with the crime preTe-.'ior. scr_ and the eredd-ng material of the present invention so as to display its: function.

;r ye A. _ A-. pr_ -e __v-' sect is c s-..^ into tr-^- :- -I so- sc---. --:-: Ohs crib pro nt--n s_r_; -- tighrened in desired places, it iS necessary to engage The end portion c the tool such as the square bar sc-n-e or th_ dri;sr with the reessd polio.. c_ the screw head and -a green the s_-e^. i.-. is b_cus_ -- In:-_ embedding material is not embedded in the recessed portion after the screw is tightened, the screw is loosened or drawn out by using the tool.

If the various screws including the above-mentioned crime prevention screws and the embedding materials are not combined as sets correspondingly, they are not convenient and are hardly sold. This is applied also to the crime prevention seat.

For this reason, in a tenth aspect, theinventors allows also a crime prevention screw set, which is composed of combinations of the crime prevention screw according to one of the first through fourth aspects or the other various screws, the embedding material of a screw head according to one of the fifth through eighth aspects and/or the screw-use crime prevention seat according to the ninth aspect, to cover the present invention.

In the present invention, as for various screws, various screws conventionally in the market can be used suitably.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a front view of an automobile showing a state that a number plate is attached to a car body by using screws of 'he convent anal art.

Fig. 2 is an enlarged diagram showing a main s=_t cn. o Elf. . :. -s = e-s-cive ei s-o;--. a s-_ e grid is attached to a window flame by using the screws of the conventional art.

Fig. :(- is a side c-cs^- se-t-onal view showing an enlarged main sect an c_ -lo. _.

Fig. 4(b) is a side cross sectional view showing an enlarged main sectio.. of Fig. 3.

Fig. 5 is a perspective view showing a crime prevention screw according to a first embodiment of the present invention and a corresponding embedding material according to the first embodiment.

Fig. 6(a) is a front cross sectional vie, showing the first step of a using method of the crime prevention screw and the embedding material.

Fig. 6(b) is a front cross sectional view showing the final step of the using method of the crime prevention screw and the embedding material.

Fig. 7 is a perspective view showing a crime prevention screw according to a second embodiment of the present invention and a corresponding embedding material according to the second embodiment.

Fig. 8(a) is a front cross sectional view showing the first step of a using method of the crime prevention screw and the embedding material.

Fig. 8(b) is a front cross sectional view showing the final step of the using method of the crime prevention screw and the embedding material.

Fig. 9 is a perspective view showing a crime prevention screw according to a third embodiment of the present invention and a c^.resconinc3 e-. bedin material according to the-third embodiment.

En'. .(_) is - Amp- cress sect o'.-2 viny sho,rin- c-,- Is s ^-i c_, -1;. ^ t:- : ._ c--;en.=l^,- screw and the e-.=eddi.-.g uteri_.

Fig. lO(b) is a front cross sectional view showing the final step of the using method Or the crime __;_.. _Q;! _:__,r: : i._ _:_c_: ._ _.

Fig. 11 is a perspective view showing a crime prever.tior. screw according to a -worth embodiment of the present invention and the corresponding embedding material according to the first embodiment.

Fig. 12(a) is a front cross sectional view showing the first step of a using method of the crime prevention screw and the embedding material.

Fig. 12(b) is a front cross sectional view showing the final step of the using method of the crime prevention screw and the embedding material.

Fig. 13 is a perspective view showing a crime prevention screw according to a sixth embodiment of the present invention and the corresponding embedding material according to the fourth embodiment.

Fig. 14(a) is a front cross sectional view showing the first step of a using method of the crime prevention screw and the embedding material.

Fig. 14(b) is a front cross sectional view showing the final step of the using method of the crime prevention screw and the embedding material.

Fig. 15 is a perspective view showing the crime prevention screw according to the third embodiment of the present invention and a corresponding embedding material according to a fifth embodiment.

Fig. 16(a) is G frort crass sectional view shoring the first step of a using method of the crime prevention sew a:!d the e.._e-:ding r-ie'2_.

_.. Go.) _s,, _:I:,s s__ _o a_ s L. _; i ' . y The final step of -rye using m_:^.o o- An- c- .._ prevention screw and the embedding material.

g. 17 is a perspective -,-' en shoving a crime pre-,-en=2c:; so:-_; hGvring G -'_'; _ 5_ -_.: '.__ _ s.r.-'. a corresponding embedding material according to a sixth embodiment.

Fig. 18(a) is a front cross sectional view showing the first step of a using method of the crime prevention screw and the embedding material.

Fig. 18(b) is a front cross sectional view showing the final step of the using method of the crime prevention screw and the embedding material.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The objects and structures of the present invention are as mentioned above. There will be detailed below concrete embodiments of a crime prevention screw, an embedding material and a crime prevention seat of the present invention with reference to the examples shown in the attached drawings. In the attached drawings, the same reference numerals are given to overlapped portions

and the description thereof is omitted.

There will be explained below a crime prevention screw according to a first embodiment of the present invention and an embedding material of a screw head corresponding to this cr. me prevention screw with reference to Figs. 5, 6(a) a-.d 6(b).

As shown in Figs. 5 and 6(a), the crime prevention scre; 33 according to the f -so embodiment of the present invention (hereinafter, the crime prevention screw of the _--s e.boi.en) is -- c,--: -:-=zc sure;; th-. ?. C'.-'_i2r ( v _ _ _ Q - ) S. _., L _ _: i _., _ S. .j, ' C 3? S _ portion G_ a screw main odds 33= a- I;-- -^ CL spir-i g-:i-v-^ is er.gaved. A hexagonal recessed portion 33c is formed on an Upper center surface:r the screw head 33b, and a _;ess_- e..g_c.-::-_; Lactic. go;i s n i-: -h a bottom 33e of the recessed portion 33c is formed laterally around an inward e?.- portion of an inne- wall 33d of the recessed portion 33c. This hexagonal recessed portion 33c is a socket for engaging an end portion of a hexagonal bar spanner (called also as a hexagonal bar wrench), not shown, for rotating to tighten the crime prevention screw 33. In this embodiment, the engagement portion 33f is a space with a slight height which becomes wider upward.

An embedding material 14 of the screw head corresponding to the crime prevention screw 33 of the first embodiment (hereinafter, the embedding material of the first embodiment) is just fitted into the recessed portion 33c and has a size such that its one portion is projected from the recessed portion 33c. The embedding material 14 is formed by a soft metal material which can be buckled and is mainly composed of soft iron, lead, copper, zinc, aluminum, tin, or one kind or plural kinds of these materials.

The crime prevention screw 33 of the first embodiment having such a structure is, as shown in Fig. 6(a) for example, used for the case where two members 50, are fixed. When they are fixed, a tapped hole 60a is formed on a base member 60 and a countersink 50a is ope..ed on the member 50 to be fixr-d' and ho:: the holes 50a, 60a are matched with each other so that the screw ::a - ,c.y- Qa A-- ci-=c --all. -;-- ant erase< - rat _C the --: Beat: hole 6r_. 2- 'S Cut.G:. S e-r--- -? -shng the end portion of the hex_:onal bar wrench, no shown, into the recessed portion 33c formed on the screw head 33b and rotatin- the hexagons bar wren -.

lute- t.._;c ?...:S hi, Cal -I; - :- . l.e crime prevention screw 33 of the first embodiment in such a manner, as shown in Figs. 6(a) Lo 5(b), the embedding material i4 of the first embodiment is pushed into the recessed portion 33c of the screw head 33b so as to be embedded in the recessed portion 33c.

As for the embedding operation of the embedding material 14, the embedding material 14 is put into the recessed portion 33b and as shown in Fig. 6(b) the upper end of the embedding material 14 which is projected upward from the recessed portion 33b is tapped by a hammer or the like so that the embedding material 14 is embedded in the recessed portion 33b completely. As a result, since the embedding material 14 is formed by the soft metal material, a lower portion of the embedding material 14 is pushed into the bottom 33e of the recessed portion 33b strongly to be buckled and the buckled portion spreads sideways. The spread portion 14a goes into the space as the engagement portion 33f in the recessed portion 33b so as to be caught in the engagement portion 33f. Moreover, since the entire embedding material 14 is pushed against the recessed portion 33c by the tapping, the embedding material 14 cannot slip out of the recessed portion 33c or cannot be drawn out forcibly.

The crime prevention screw 33 of the first embodiment and 'he e.-.-edd_n ma-_rial t o -e first embodiment may be sold separately, but a screw set G1 com?o--ed o - c--.e c-e--_r. Oh sir_;; 33 and the = i--i-- =.-.- i=.1 s c-. -- _-.-- He = A-_ s_re; S_.: prevents consumers from boding CalLosing a-. in_pjrop--iate embedding material.

There -ill be e<inid colon a c ime prevention a_-_- acacr-_ng. G 5 _ 2i._; ; . '_'.'i..._ -. _ C _ Go,_ p re - - .,_ invention and an embedding material of a screw head correspond ng to this crime prevention screw with reference to Figs. 7, 8(a) and &(D) . As shown in Figs. 7 and 8(a), the crime prevention screw according to the second embodiment of the present invention (hereinafter, the crime prevention screw of the second embodiment) 34 is a round head screw that a round (viewed from top) screw head 3G.b is formed on a base portion of a screw main body 34a on which a spiral groove is engraved. A linear (viewed from top) recessed portion 34c composed of a slot is formed on an upper center surface of the screw head 34b, aid a recessed engagement portion 34f which is integral with a bottom 34e of the recessed portion 34c is laterally formed on an inward end portion of an inner wall 34d of the recessed portion 34c.

The recessed portion 34c composed of the slot is a socket for engaging an end portion of a minus driver (called also as a flat screwdriver), not shown, for rotating to tighten the crime prevention screw 34. In the present embodiment, the engagement portion 34f is a space with slight height formed so as to be expanded sideways.

The crime prevention screw 34 of the second embodiment having such a structure is, as shown in Fig. 8(a) for example, used for the case where two members 50, are fixer.. This t^ixin_ open_ or. is performed in the approximately same procedure as the above-mentioned _.::_- i^ _si:^e --my or.

-.e^ the -ail- ---I-:- it a:- -exact -i.-i.: to;-?.

cr. me prevenlio.. screw 34 c -. e second embod dent in such a manner, as shown in Figs. 8(a) to 8(b), an e,_e.-d-ng material 15 of the s_-_: ^ead (hereinafter, the e-.--_A -.j m Celia c_.-e s-_s:- e^.-__ m_-) is -pi s-:-i_ into the recessed portion 34c o the screw head 34b so as to be embedded in the recessed portion Sac.

The procedure for embedding the embedding material of the second embodiment is the approximately same as that of the first embodiment. The embedding material 15 is inserted into the recessed portion 34c of the screw head 34b and the uppe- end portion of the embedding material 14 projected from the recessed portion 33c is tapped by a hammer or the like so that the Embedding material 15 is embedded in the recessed portion 34b completely.

With such a structure, the lower portion of the embedding material 15 is strongly pushed against the bottom 34e of the recessed portion 34b so as to be buckled and the buckled portion spreads sideways. The spread portion 15a goes into a space as the engagement portion 34f in the recessed portion 34b so as to be engaged with the engagement portion 34f. Moreover, since the entire embedding Material 14 is pushed against the recessed portion 34c by the tapping, the embedding material 15 cannot come out of the recessed portion 34c.

It is preferable that the crime prevention screw of the second embodiment and the embedding material 15 of the second embodiment are sold as a crime prevention s rew set G2 si=.ilar2, -a the first embodiment.

There will be explained below a crime prevention

-

s.::- c.. or.i. .c r, _ C O d =e _ O f.r.e -s=- ;'.-! ,' =- ^.''. C:. e: :--.: o a s--e; ;_^ according to snorer ___ a.--. c_r-eso_r.d no.o.is crime prevention soreFaith reference to Pigs. 9, lO(a) and lO(b).

is a_;. :.: _c_. _:._ _ _, _ c _e p__.e:_o screw 35 of the third embodiment is the round head screw the a s_re''i head 3Sb is formed roundly and a hexagonal recessed portion 35c is formed on the center of the screw head 35b. Since the other portions are the same as those of the above-mentioned crime prevention

screw (33), the description thereof is omitted.

An embedding material 16 of a screw head according to another embodiment to be used here (hereinafter, the embedding material of the third embodiment) is slightly different from the embedding material of the first embodiment. The embedding material 16 has an outer peripheral shape such that it is just fitted into the recessed portion 35c and is constituted so that a buckling member 16b having a lower height than that of an embedding material main body 16a is fixed to a lower surface of the embedding material main body 16a having a slightly Lowe- height than the height of the recessed portion 35c. The embedding material main body 16a is made of comparatively soft metal such as iron, copper, brass or aluminum. The buckling member 16b is made of a soft metal material which can be buckled and mainly contains soft iron, lead, copper, zinc, aluminum or tin or one kind or plural kinds of them.

Sin-e the use objects and the embedding method and ties pr_;^ni n of slipping-of of the embedding r..ateial 16 of the third embodiment are the approximately same as t..- ;-.s 0..s e.

_.A _. L: _; . . d_s__ it:. t. L _ _ ec_ _s - - T O, ; O L - e.. . material 16 is made of hard metal, parcicularly-, t - s_.=e met-3 r..ateri- as tha. of the screw head 35b, It appears that the embedds.r.. portion of the embedding material 16 is inter rat Vi- t-...DTD: -.s screw A_-_ _. for..-s re___,n, -. e appearance is good and even if the embedding material 16 is i- ed to oe forcibly broken by an end portion of a drive-, it cannot be broken. As a result, the case that the crime prevention screw 35 is drawn out can be prevented more efficiently...DTD: It is desirable that the embedding material 16 is combined with the corresponding screw 35 to be sold as a crime prevention screw set G3.

There will be explained below a crime prevention screw according to a fourth embodiment of the present invention and an embedding material of a screw head of another embodiment corresponding to this screw with reference to Figs. 11, 12(a) and 12(b).

As shown in Figs. 11 and 12(a), the crime prevention screw 36 according to the fourth embodiment of the present invention (hereinafter, the crime prevention screw of the fourth embodiment) has a form such that the outer peripheral end of the screw head (33b) of the crime prevention screw (33) of the first embodiment shown in Fig. 5 is cut roundly. The other portions are the same as those of the crime prevention screw (33) or the first embodiment, and 36c denotes a recessed portion and 36f denotes an engagement portion.

In addition, the embedding material la of a screw he_ 30o corresponding to tr.e _rm prevention screw 36 of- the fourth embodiment which is the same as the _m _ ng I-- eria ('.4' t-. fir.- e-ocdime.. is used an -is -I this e-o- dimer. it s desir ?.2 le t:h&- the cri.e pe;-e-.tion scre. 36 and the e;;o_dair.c; material 1- are sold as a crime prevention screw set G4.

Since their using method is the approximately same as that in he above exp_G-t-t-o.., -:-_ c_scr-p--icr. o the method is omitted. The crime prevention screw 36 of the fourth e'oodiment, as mentioned above, has the screw head 36b with round outer peripheral end and has a doughnut shape (viewed from top). It is more desirable that the crime prevention screw 36 is combined with a screw-use crime prevention seat 40, which is formed with a rise portion 40a having roundness which surrounds a side wall of the screw and is hardly pinched by a tool such as pincers or pliers, so as to be sold as a crime prevention screw set G5.

When the screw-use crime prevention seat 40 is used, the screw head 36b is housed in the rise portion 40a of the screw-use crime prevention seat 40 so as not to be pinched by the tool such as pincers or pliers.

Further, even if the crime prevention seat 40 is tried to be pinched and rotated by using such tools, it cannot be pinched due to slipping. Moreover, even if the crime prevention seat 40 is forcibly pinched and rotated, only the crime prevention seat 40 is rotated idle. For this reason, the screw cannot be drawn out mockingly or with the intention of crime.

There will be explained below a crime prevention screw according to a fifth embodiment of the present invention and an embedding material of the fourth embodiment correspond-.,g to thins c-i.-.._ prevent on screen? with reference to Figs. 13, 14(a) and 14(b).

Is sho-i- in - USA 13 a..d 14 gal. w:.-n a-; crim- pr- -_n_'. 0? sire-; 37 I- Am- r-- ,? 2_ - i_. - ao-^m,^- coed crime prevention screw 36 of the fourth e.bciment, a structure of an engagement portion 37f of a recessed portion 37c is difr-<ent. The recessed portion 37c or.ed on the screwhead 37c Cal c.he c it-e ?e---nt on screw 37 of the fifth embodiment is formed by a hexagon socket, and the recessed engagement portion 37f in which its inside is wider than its entrance is foamed on a bottom 37e.

An embedding material 17 of the screw head of the fourth embodiment corresponding to the crime prevention screw 37 (hereinafter, the embedding material of the fourth embodiment) has a shape and a size such that it can embed in the recessed portion 37c. Theembedding material 17 is composed of two members: an embedding material main body 17a formed with a recessed engagement portion 17c having a shape such that its inside is wider than its entrance at an end surface of the embedding material 17; and a connecting member 17b made of a soft metal material which is buckled in both the recessed portion 17c and the engagement portion 37f of the crime prevention screw 37 and fixes the embedding material main body 17a into the recessed portion 37c of the crime prevention screw 37.

As for the using method of the embedding material 17, one end of the connecting member 17b is pushed into one of the engagement portions 37f, 17c and the other end of the connecting member 17b is pushed into the other engagement portion so that the embedding material main body 17a is put into t'.ne recessed portion 37c. The upper end of the embedding material main body 17a which is pick G e Spear-' rcm t-.e +^-ese-. heir ice. 3,c s tapped by a harden or t-.* 1 2'.?. and tic? cOnr.^o- .'" re.e^ 17b -s buckled in both the enyagem_n pore c..5 37f, 17c so as not to come off.

With such a structure, similarly to:'-ne above _I___,:.___s, .;:* ;.y A____ l, (substantially the embedding material main body 17a) is embedded in the recessed portion 37c of the screw head 37b so that the embedding material 17 cannot be drawn out.

It is desirable that the embedding material 17 is also combined with the corresponding crime prevention screw 37 and the above-mentioned screw-use crime prevention seat 40 so as to be sold as a crime prevention screw set G6.

There will be explained below an embedding material of a screw head according to a fifth embodiment of the present invention with reference to Figs. 15, 16(a) and 16(b).

The embedding material 18 of a screw head according to the fifth embodiment of the present invention corresponds to the crime prevention screws of the above embodiments other than the crime prevention screw of the fourth embodiment. In Figs. 15, 16(a) and 16(b), the crime prevention screw is shown as the crime prevention screw 35 of the third embodiment.

As shown in Figs. 15 and 16(a), the embedding material of a screw head according to the fifth embodiment of the present invention (hereinafter, the embedding material of the fifth embodiment) is a material for e beddirlg in the recessed Portion 35c composed of the hexagon socket formed on the screw head 35b of the crime pre--^n On Is-- 3D. Q._ em^e- ina.aeria 1: is -orbed 6, _ S _ hi S 'by. - _ = :-. 1 S,. _ C, - ' ^ - 'I. c shape for covering rue re_ess-d portion 3c is in -g-ai vith standing portions 18b having the approximately same shape as both the inner s de walls of the recessed portion 3-c. Pro ru_ o.s;;_ G-C -or.ed on e-_ -_- ions of the outer walls of the standing portions 18b, and a force which outr.araly repulses pressurizing forces to t.e inner directions (approaching directions) is applied to the standing portions 18b.

As for the using method of the embedding material 18, as shown in Figs. 16(a) to 16(b), the embedding material 18 may be simply pressurized into the recessed portion 35c formed on the screw head 35b with the side on which the protrusions 18c are formed faces towards the recessed portion 35c.

In such a manner, the embedding material 18 embeds in and cover the recessed portion 35c, and the protrusions 18c with the applied force go into a space as the engagement portion 35f in the recessed portion 35c so that the embedding material 18 cannot be come out of the recessed portion 35c. It is desirable that the embedding material 18 is also combined with the

corresponding crime prevention screw 35 so as to be sold as a crime prevention screw set G7.

There will be explained below an embedding material of a screw head according to a sixth embodiment of the present invention with reference to Figs. 17, 18(a) and 18(b).

.n e ed-ng ha trial 13 of a screw head a cording to the sixth embodiment of the present invention :-,2-?, t'.= e!2-'- a.-, t'.c.te'- _2' 0- .he s. _:- - it') ca- c ---^-3 t^ --:-: call t-- . prevention screws of -.r.e ao- v-e emboclments by also screws conventionally in the market. For this reason, in Figs. 17, 18(a) and 18(b), the embedding material 19 corresponds -cc..1_ sc_'i c to-_ o.--e-._cn- G '.. C- 2^. e hexagonal recessed portion 36c is formed on the screw heat Bob.

The embedding material 19 is formed by a soft metal material such as iron, copper, stainless, aluminum or tin having a size for embedding in the recessed portion 36c formed on the screw head 36b. Small rags 19a having an acute angle which are slanted and raised from the embedding direction to the opposite direction are formed on the side walls of the embedding material 19.

When the embedding material 19 is formed in such a manner, as shown in Fig. 18(b), the embedding material 19 is embedded in the recessed portion 36c by pressurizing the embedding material 19 thereinto through tapping via a hammer or the like. Further, the rags 19a come deeply into the side wall 36d of the recessed portion 36c so that the embedding material 19 does not come off.

It is desirable that the embedding material 19 is also combined with the corresponding screw 36 so as to be sold as a crime prevention screw set G8.

The above-mentioned embodiments explained mainly about the screws that their recessed portion formed on their screw heads are hexagonal and about the corresponding embedding materials. However, in the respective embodiments, screws that their recessed portions hav ^g anomie' she es, such as a square shape, a cross shape and a slot shape, and corresponding embedding a'_ri-.'s m=.- be use_.

::^ ^. - .-i_ preverion stews, -;^ e--e. n^ n;__eri-_s c so_-_: .---.-s an-i:-e a_-_;- s_ c- -;.

prevention seats according to the present invention are used to ether, the embedding materials can _- er.oedded in r e::_s-_- -c--c:-_ I- c^ - ::--;---- so _- r, ^ to come off after the screws are tightened. For this reason, the drawing-ou of the screws moc7. 'ingly or with the intention of crime can be prevented. Concretely, the present invention shows effects such that crimes, such as car stealing through removal of a number plate of an automobile by drawing out the screws, resale and export of stolen automobiles, stealing and kidnapping using a stolen car, stealing of a car stereo and a car navigation device in an automobile, can be prevented.

In addition, the present invention shows an effect such that a criminal is previously prevented from drawing out screws for fixing an outer grid of a window and a key of a door in a house and from intruding through the window or the door into the house and from committing stealing and bestial crime.

Claims

Claims: 1. A crime prevention seat for use with a crime prevention screw

having a screw head, said screw head having a recessed portion composed of a square socket, hexagonal socket, cross socket or a slot for engaging and rotating an end portion of a tool such as a square bar spanner or a driver, and a recessed engagement portion formed on part of an inner wall of the recessed portion for engaging with an embedding material in the recessed portion such that removal of the embedding material can be prevented, wherein the crime prevention seat has a doughnut shape when viewed from above to allow a main body of a crime prevention screw to pass through it and receive the screw head, and wherein a rounded rise portion is formed around the seat such that it surrounds the side wall of the screw head when it has been received by the seat such that it is difficult to nip the screw head with a tool such as pincers or pliers.
2. A crime prevention seat for a screw head substantially as hereinbefore described, with reference to any one of Figs. 11, 12(a) and 12(b), and Figs. 13, 14(a) and 14(b) of the accompanying drawings.
3. A crime prevention screw, wherein a recessed portion which is composed of a square socket, a hexagon socket, a cross socket or a slot for engaging and rotating an end portion of a tool such as a square bar spanner or a driver is formed on a screw head, and a recessed engagement portion is formed on a partial place of an inner wall of the recessed portion such that one of an expanded portion formed by buckling a part of an embedding material for embedding in the recessed portion and a protrusion to which a force is applied to the side of the embedding material for embedding in the recessed portion comes into the engagement portion, whereby the embedding material is prevented from coming off.
4. A crime prevention screw, wherein a recessed portion which is composed of a square socket, a hexagon socket, a cross socket or a slot for engaging and rotating an end portion of a tool such as a square bar spanner or a driver is formed on a screw head, and a recessed engagement portion where its inside is wider than an entrance is formed on a bottom portion of the recessed portion such that one of a protrusion formed at an end of an embedding material for embedding in the recessed portion and one end portion of a connecting member for connecting the embedding material to the screw head comes into the engagement portion, whereby the embedding material is prevented from coming off.
5. The crime prevention screw according to claim 3 or 4, wherein said crime prevention screw is one selected from a machine screw, a set screw, a square screw, an embedded screw, a bolt or a wood screw.
6. The crime prevention screw according to claim 3 or 4, wherein the screw head of said crime prevention screw is formed into a curved surface shape which is hardly pinched by a pinching tool such as pincers.
7. An embedding material of a screw head for embedding in the recessed portion for pushing a tool thereinto, composed of a square socket, a hexagon socket, a cross socket or a slot, the recessed portion being formed on the screw head of said crime prevention screw according to one of claims 3 through 6, wherein said embedding material has a shape and a size such that it can be buckled in and can embed in the recessed portion and at least an end portion of said embedding material is made of a soft metal material which can be buckled and mainly contains soft iron, lead, copper, zinc, aluminum or tin, or one kind or plural kinds of them.
8. The embedding material of a screw head according to claim 7, wherein said embedding material has a shape and a size such that it can be buckled in and can embed in the recessed portion for pushing a tool thereinto, which is formed on the screw head of the crime prevention screw and is composed of a square socket, a hexagonal socket, a cross socket and a slot, and is composed of two members: an embedding material main body which is formed with a recessed engagement portion having a shape such that an inside is wider than an entrance at its end surface; and a connecting member which is buckled in both this engagement portion and the recessed engagement portion formed on the bottom portion of said crime prevention screw that its inside is wider than its entrance so as to fix the embedding material main body in the recessed portion of said crime prevention screw and is made of a soft metal material mainly containing soft iron, lead, copper, zinc, aluminum or tin, or one kind or plural kinds of them.
9. An embedding material of a screw head, for embedding in the recessed portion for pushing a tool thereinto, composed of a square socket, a hexagon socket, a cross socket or a slot, said recessed portion being formed on the screw head of said crime prevention screw according to claim 3 or 4, wherein said embedding material has a shape and a size such that it can embed in the recessed portion and an end portion of said embedding material is formed with a protrusion which comes into the engagement portion of claim 3 or 4 with a force is applied to the protrusion.
10. An embedding material of said crime prevention screw of one of claims 8 through 6, wherein said embedding material is a material for embedding in the recessed portion, for pushing a tool thereinto, composed of a square socket, a hexagon socket, a cross socket or a slot and has a shape and a size such that it can embed in the recessed portion through tapping or pressurizing-into and a suitable portion of its side wall is formed with rags or burrs for preventing said embedding material from coming off.
11. A screw-use crime prevention seat having a doughnut shape viewed from top, said seat being fitted into the screw main body of said crime prevention screw according to one of claims 3 through 6 and being received by the screw head, wherein a rise portion having roundness, which surrounds the side wall of the screw head and is hardly nipped by a tool such as pincers or pliers, is formed around said seat.
12. A crime prevention screw set composed of the combinations of said crime prevention screw according to one of claims 3 through 6 or another various screws and said embedding material of a screw head according to one of claims 7 through 10 and/or said screw-use crime prevention seat according to claim 11.