Pin for injecting a grout material

A pin for injecting a grout material comprising an upper structure (I) into which an upper half portion (1') wherein a screw thread (2) and a lengthwise hole (3) are formed, a packing (4), a washer (5) and a knock pin (11) for knocking a grout pin (10) are inserted, and a lower structure (II) into which a lower half portion (1"), both tongued pieces (7', 7") of a slit wherein said slit (7) and a knurling portion (8) are formed and in the space formed by both tongued pieces (7', 7"), through the lengthwise hole (3) of said upper structure, the grout pin and the knock pin for knocking said grout pin are inserted.

FIELD OF THE INVENTION 
The present invention relates to a pin for injecting a grout material for 
reparing or preventing surface peel-off of mortar coated walls or 
strengthening the inside of a structure destroyed due to weakness thereof. 
BACKGROUND OF THE INVENTION 
In general, the wall surface to which mortar is coated is apt to peel-off 
after a long period of time owing to a peel-off phenomenon caused between 
the mortar wall surface and the wall itself; and at last the so-called 
peel-off phenomenon may often be observed. Furthermore, it is necessary to 
integrate the deteriorating mortar wall surface with the wall itself by 
filling up the space thus caused owing to the cracked or seceded portion 
of concrete or bricks by employing a suitable adhesive agent. 
According to conventional execution of workings, a number of anchor bolts 
are knocked into almost the entire area estimated as being destroyed; and 
thereafter a grout material such as cement mortar is injected into a 
position or place in the vicinity of the estimated destroyed area. 
However, in the case of the above conventional execution of workings, it 
was impossible to retain the mortar wall surface as it was owing to a high 
pressure action at the time of the injection of the grout material and 
accordingly a space between the mortar wall surface and the wall itself 
increased owing to the action of the grout material thus injected, which 
inevitably caused the enlargement of cracks. 
SUMMARY OF THE INVENTION 
An object of the present invention is to constitute a pin for injecting a 
grout material without causing the defects of the conventional execution 
of workings. The above-mentioned object can be attained with a pin for 
injecting a grout material which comprises an upper structure of a 
cylinder provied with a screw thread and a lengthwise hole respectively 
arranged at an upper-half portion which is somewhat shorter than half of 
the whole thereof, a packing and a washer respectively made of an elastic 
material such as a rubber or synthetic material etc., being fitted into 
said shorter, upper-half portion in order to prevent the counter flow of a 
grout material, a washer based nut being screwed into said screw thread 
and a knock pin for knocking a grout pin into said hole and a lower 
construction consisting of a slit formed directly below said packing being 
arranged at a lower-half portion which is longer than approximately half 
the length of the whole of said cylinder, a knurling portion being formed 
on both tongued pieces of said slit of the front end of said lower-half 
portion and further a knock pin knocking the grout pin being inserted into 
a space formed by said tongued pieces just like said grout pin through the 
lengthwise hole of said peel construction. 
The present invention is an improvement of a pin for injecting a grout 
material as disclosed in Japanese Utility Model Application No. Sho 
55-80277 (Utility Model Publication No. Sho 60-40766) filed in the name of 
the present applicant; and according to the present invention, it is 
possible to inject the pin for injecting the grout material in deeper 
portions as far as a space of the lengthwise hole in comparison with the 
aforementioned publicly known pin for injecting a grout pin.

DETAILED DESCRIPTION OF THE PREFERED EMBODIMENTS OF THE INVENTION 
As shown in FIG. 1, a pin for injecting a grout material according to the 
present invention comprised a cylinder 1. Said cylinder 1 consists of two 
constructions (I) and (II). Said constructions consist of an upper-half 
portion 1' which is shorter than approximately half the length of the 
whole of the whole of said cylinder 1 as the construction (I) and a 
lower-half portion 1" which is longer than said portion 1' as the 
construction (II). 
On said upper-half portion 1', a lengthwise hole 3 is perforated to 
penetrate through the central portion of a screw thread 2 and said 
cylinder 1. Said hole 3 may serve to insert thereinto a grout pin 10 
formed approximately in the shape of a trapezoid and a pin 11 for knocking 
said grout pin 10 onto said shorter upper-half portion 1', a packing 4 
made of, for example, such an elastic material as a rubber or synthetic 
material etc., for preventing the counter flow of the grout material and 
provided with a central hole having approximately the same diameter as 
said cylinder so as to be self-suspended by said cylinder and further a 
washer 5 abutting said packing 4 are fitted. Furthermore, at the time of 
an operation, a washer based nut 6 is screwed into a screw thread 2 in 
order to check the aforementioned constitutional elements. In this case, 
the washer 5 can retain the pin for injecting a grout material to be a 
suspended condition because said washer 5 has a larger diameter than that 
of the hole perforated in the construction into which the pin for 
injecting the grout material is inserted. 
In the lower half portion 1" which is longer than approximately half the 
length of the whole of said cylinder 1, a slit 7 is formed directly below 
the lower portion of said packing 4, while on the other hand two tongued 
pieces 7', 7" forming a slit 7 are formed at the front portion of said 
lower half portion 1" and furthermore the knurling portion 8 is formed on 
said tongued pieces 7', 7" in order to permanently anchor said cylinder to 
a constructing body when the cylinder is expanded by knocking the grout 
pin 10 thereinto by means of the knock pin 11. 
In carrying out an actual operation, the grout pin 10 is inserted through 
the lengthwise hole 3 of the aforesaid construction and the knock pin 11 
is also inserted in order to knock same thereinto. 
Hereinafter, embodiment of the use of the pin for injecting a grout 
material according to the present invention will be described in detail 
with reference to the FIG. 2 to FIG. 8. 
At a central portion of the peeled-off mortar (or a bond), a hole with a 
diameter somewhat larger than that of the pin for injecting a grout 
material is perforated; and thereafter said pin is inserted thereinto. The 
packing 4 and the washer 5 fitted onto said packing 4 are inserted, 
thereby softly fixing the washer based nut 6 thereto by the screw thread 
2. Thus, the grout pin 10 is knocked into the base of the cylinder by 
means of the knock pin 11. At that time, the front portion of the pin, 
i.e. both tongued pieces 7', 7" are expanded to open, thereby thrusting 
the pin into the concrete (FIG. 2). At that time, the nut 6 is clamped so 
as to fix the packing 4 thereto under pressure. Under such conditions as 
above, the pin for injecting a grout material is kept in a suspended 
condition. Then, a grout pipe 9 is connected thereto so as to inject the 
grout material (FIG. 3). Thus, the grout material is injected into a space 
to be treated formed on the whole of the end faces of the tongued pieces 
7', 7" from every position of the slit. As a result of said injection, the 
grout material causes the excretion of water which exists in the spaces of 
the grout material. After confirming the hardening of an adhesive agent, 
the nut and packing 4 are respectively taken off (FIG. 6). In this manner, 
the adhesive agent can be filled up the spaces without causing rises of 
the mortar surface (a tile) layer to be thus treated owing to an injection 
pressure in carring out the execution of workings. 
Lastly, a head portion of the grout pin is cut to a concave shape by means 
of a grinder (FIG. 5) and thereafter a pin with a disc head is knocked 
into the hole of the grout pin (FIG. 6). 
At that time, the head of the pin can retain the mortar layer; and at the 
same time the grout pin can serve as an anchor.